Bacteriophage Ecology Group
Reference Abstracts (1990)
Dedicated to the ecology and evolutionary biology of the parasites of unicellular organisms (UOPs)
© Stephen T. Abedon
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© Phage et al. last updated on Wednesday, December 26, 2001
  1. Introduction of genetically modified organisms into the environment. Anonymous (1990). Wiley, New York.[TOP OF PAGE]

  2. Bacteriophage therapy of pseudomonas burn wound sepsis. Abdul-Hassan, H.S., El-Tahan, A., Massoud, B., Gommaa, R. (1990). Annals of the Mediterranean Burn Club 3, 4:262-264. [TOP OF PAGE]

  3. Selection for lysis inhibition in bacteriophage. Abedon, S.T. (1990). J. Theor. Biol. 146:501-511. For Escherichia coli cells that have been infected by T-even bacteriophages (phages T2, T4, and T6), the adsorption of a second T-even phage results in an increase in the length of the original phage infection and an associated increase in the number of phages produced by the same infected cell. This is a phage encoded response called lysis inhibition. In this study the ecological significance of lysis inhibition is explored. In particular it is argued that lysis inhibition is an adaptive response to environments containing high concentrations of infected cells and low concentrations of uninfected cells. [TOP OF PAGE]

  4. The Ecology of Bacteriophage T4. Abedon, S.T. (1990). University of Arizona. In this dissertation I explore the ecology of bacteriophage T4, a virus of Escherichia coli. In particular, I argue that the life history of bacteriophage T4 can be divided into the growth and survival of T4 phages in three distinct environments. I argue that these environments are distinguished by at least two T4 phage sensory systems. These include (i) the sensing of secondary adsorption by infecting phages and (ii) the determination of the concentration of monovalent cations and free tryptophan in solution about free T4 phage particles. The first environment consists of high concentrations of uninfected, logarithmic phase E. coli cells. These concentrations are approximately 106 E. coli cells/ml and greater. This environment occurs in the prefecal colonic lumen of animals. Here T4 phages exhibit unimpeded logarithmic growth. The second environment contains high concentrations of infected E. coli cells, low concentrations of uninfected E. coli cells, and high concentrations of free T4 phage particles. This second environment also occurs in the prefecal colonic lumen of animals and represents the maturation of environments supporting logarithmic T4 phage population growth. Such phage phenotypes as secondary exclusion and lysis inhibition characterize T4 phage growth in this environment. The third environment consists of extra-colonic waters. Here T4 phages avoid infecting E. coli cells and exhibit strategies that maximize their stability. These strategies in extra-colonic waters increase the potential of T4 phages to disseminate successfully from colon to colon. I employ this enhanced understanding of T4 phage ecology, outlined above, in an exploration of the ecology of the repair of DNA damage by T4 phages. [TOP OF PAGE]

  5. Isolation and primary characterization of a new bacteriophage of obligate methylotrophic bacteria. Almumin, S., Kadri, M., Mamat, U., Engel, J. (1990). Journal of Basic Microbiology 30:627-633. .vf.KISR 1, a new bacteriophage of obligate methylotrophic bacteria, was isolated from a local pilot plant. The phage belongs to the Podoviridae family of viruses characterized by a short non-contractile tail and double-stranded DNA. The size of phage genome was determined on the basis of electron micrographs and restriction enzyme analysis to be about 46 kb. The host range of .vf. KISR 1 is restricted to three very closely related methanol-utilizing KISR strains belonging to the genus Methylophilus. The phage does not originate from the methylotrophic KISR strains which were tested for lysogeny. [TOP OF PAGE]

  6. Further biological and molecular characterization of actinophage VWB. Anne, J., Van, M.L., Decock, B., Van, D.J., Van, A.A., Herdewijn, P., Eyssen, H. (1990). Journal of General Microbiology 136 ( Pt 7):1365-1372. The development cycle of the temperate actinophage VWB was investigated. Adsorption of most phage particles occurred within 30 min and the adsorption constant was 0.6 x 10(-8) ml min-1. The latent and rise periods were 140 and 100 min, respectively, and the burst size was estimated to be 130-250 p.f.u. Although phage VWB could infect only Streptomyces venezuelae ETH 14630 (ATCC 40755), of six different S. venezuelae strains tested, phage DNA could be introduced by transfection into most non-infectible strains. Upon transfection, phage DNA was propagated in these non-infectible strains and phage particles were released. In addition, the transfected strains could be lysogenized. By comparison of restriction fragments of VWB DNA, either free or integrated in the chromosomal DNA of the S. venezuelae ETH 14630 lysogen, the attachment site was localized. PAGE of the phage proteins revealed at least 17 different proteins with three major bands estimated as 16.5, 27.2 and 43 kDa in size. The N-terminal amino acid sequence of these supposed major head and tail proteins was determined. The corresponding DNA sequences on the phage genome were localized using oligonucleotides synthesized on the basis of the N-terminal amino acid sequences. The genes coding for the major structural proteins were shown to be clustered, as has been observed for other bacteriophages. [TOP OF PAGE]

  7. Sensitivity to phages of Streptomyces coelicolor strains harbouring type II restriction endonucleases. Aparicio, J.F., Barbes, C., Hardisson, C., Sanchez, J. (1990). Microbiologia 6:71-75. The role of type II restriction endonucleases in phage development in two different strains of Streptomyces coelicolor has been analyzed. Two of ten phages tested (phi A4 R4c 1) presented a low efficiency of plating (e.o.p.) in the studied strains. The isolation of host-range mutants of phi A4 and R4c 1, with improved e.o.p. and higher adsorption capability in these two bacterial strains, suggests that the presence of host endonucleases is not the main barrier for these phages, but rather adsorption inability. [TOP OF PAGE]

  8. USING BACTERIOPHAGE FOR SLIME CONTROL IN THE PAPER MILL. ARAKI, M., HOSOMI, M. (1990). TAPPI (Technical Association of the Pulp and Paper Industry) Journal 73:155-158. Using bacteriophage for slime control in the paper mill.Conventional biocides can lose their effectiveness over time, and their nonselective attack on microorganisms can impair the efficiency of activated-sludge waste-treatment systems. As an alternative, the authors propose using bacteriophage-a type of virus that selectively destroys its host bacteria - as a slime-control agent in the paper mill. Slime-forming bacteria and their associated bacteriophages were isolated in the white water from a fine-paper mill. In vitro experiments showed that growth of slime-forming bacteria was greatly retarded in the presence of its corresponding bacteriophage. These results indicate that addition of bacteriophage to mill white water may be an effective technique for slime control. Simultaneous addition of bacteriophage with conventional biocides also was found to be effective. Practical application of this technique on a commercial scale awaits completion of fundamental studies in several key areas. [TOP OF PAGE]

  9. Isolation and characterization of bacteriophages from Myxococcus virescens. Azuaga, M.J., Munoz, J., Gonzalez, F., Arias, J.M. (1990). Microbios 61:83-88. Four bacteriophages from Myxococcus virscens were isolated from manure and fertilized soil samples. They were designated Mv-1 g1, Mv-1 g2, Mv-8 g1 and Mv-8 g2. Both phages Mv-1 produced clear plaques and consisted of a polyhedral head (78 .times. 87 nm) and a tail of 105 nm with a baseplate. Phages Mv-8 were smaller, with an isometric head of 78 nm and a tail of 50 nm and produced turbid plaques. Although the bacteriophages Mv-1 g1 and Mv-1 g2 were morphologically very similar, the adsorption of the former was strongly increased by Ca2+, while that from the latter was not so affected by this ion. Phages Mv-8 could be distinguished one from the other because Mv-8 g1 adsorbed on Myxococcus coralloides D, but this was not so for Mv-8 g2. [TOP OF PAGE]

  10. Evidence of neutralizing activity against T3 coliphage in oyster Crassostrea gigas hemolymph. Bachere, E., Hervio, D., Mialhe, E., Grizel, H. (1990). Dev. Comp. Immunol. 14:261-268. To investigate defense reactions of bivalve molluscs against viruses, experimental in vitro assays have been developed using T3 coliphage as a test virus. A native neutralizing factor in oyster Crassostrea gigas serum showed high individual variability and was enhanced significantly by repeated sampling of hemolymph from the same oysters. The responsible factor is apparently thermolabile and sensitive to EDTA treatment. Because of an inhibitory effect by the enzymatic inhibitor, phenylmethylsulphonyl fluoride (PMSF), the T3-neutralizing factor may be related to serine protease. [TOP OF PAGE]

  11. Comparative survival of enteric viruses and coliphage on sewage irrigated grass. Badawy, A.S., Rose, J.B., Gerba, C.P. (1990). J. Environ. Sci. Hlth. 1425:937-952. [TOP OF PAGE]

  12. Modeling bacteriophage transport through porous media; laboratory experiments with silica beads. Bales, R., Hinkle, S., Kroeger, T., Stocking, K. (1990). Eos, Transactions, American Geophysical Union 71:1324 [TOP OF PAGE]

  13. [Interactions of the phytopathogenic bacteria Erwinia with phage P1 CRL100 CML]. Beliasova, N.A., Prokulevich, V.A., Fomichev, I. (1990). Molekuliarnaia Genetika, Mikrobiologia, i Virusologa 14-18. The bacteriophage P1 Cm clr100 lysogenises the bacteria E. chrysanthemi, E. aroideae, E. atroseptica being localized in the cytoplasm, replicating but causing no cell lysis. The prophage induction results in transformation of the lysogenic bacteria E. chrysanthemi into nonviable filamentous cells. However, a portion of cells gets rid of the prophage and gives rise to normal heritage inheritors permitting to use the bacteriophage as an efficient vehicle for introducing the transposons into the chromosome of E. chrysanthemi. The transposon Tn9 has been found to insert into the different chromosomal sites causing no inactivation of the genes, while the transposition of Tn5 from the bacteriophage P1::Tn5Cmclr100 induces the different mutations with the frequency up to 3%. The bacteriophage P1Cmclr100 may also serve a tool for construction of the homology regions in the chromosome of E. chrysanthemi and Flac+ plasmid for further construction of Hfr-type donors. [TOP OF PAGE]

  14. A note describing a bacteriophage aerosol model of droplet infection to assess the viral barrier properties of filters. Betts, W.B., Mould, A., Clough, G. (1990). Microbios Letters 45:57-60. A model system to mimic droplet transmission of viruses was developed using an aerosol of bacteriophage infecting Serratia marcescens. Phage was sprayed as a water suspension onto Petri dishes with lids replaced by test filters. The viral barrier properties of the filters was assessed by observing plaques in the lawn of susceptible host bacteria grown previously in the Petri dish. All plates covered by filters showed no plaques indicating effective barriers to phage. Control plates with lids were also negative but plates without lids or filters exhibited much lysis of the bacterial lawns, indicating the validity of the model system. The system is safe, rapid, economical, convenient and is widely applicable. [TOP OF PAGE]

  15. Coliphages as an indicator of faecal pollution in water. Their survival and productive infectivity in natural aquatic environment. Borrego, J.J., Cornax, R., Moriñigo, M.A., Martinez-Manazanare, E., Romero, P. (1990). Water Res. 24:111-116. [TOP OF PAGE]

  16. Enumeration and biomass estimation of planktonic bacteria and viruses by transmission electron microscopy. Børsheim, K.Y., Bratbak, G., Heldal, M. (1990). Appl. Environ. Microbiol. 56:352-356. [TOP OF PAGE]

  17. Viruses as partners in spring bloom microbial trophodynamics. Bratbak, G., Heldal, M., Norland, S., Thingstad, T.F. (1990). Appl. Environ. Microbiol. 56:1400-1405. [TOP OF PAGE]

  18. Fitness of RNA virus decreased by Muller's ratchet. Chao, L. (1990). Nature 348:454-455. Why sex exists remains an unsolved problem in biology. If mutations are on the average deleterious, a high mutation rate can account for the evolution of sex. One form of this mutational hypothesis is Muller's ratchet. If the mutation rate is high, mutation-free individuals become rare and they can be lost by genetic drift in small populations. In asexual populations, as Muller noted, the loss is irreversible and the load of deleterious mutations increases in a ratchet-like manner with the successive loss of the least-mutated individuals. Sex can be advantageous because it increases the fitness of sexual populations by re-creating mutation-free individuals from mutated individuals and stops (or slows) Muller's ratchet. Although Muller's ratchet is an appealing hypothesis, it has been investigated and documented experimentally in only one group of organisms--ciliated protozoa. I initiated a study to examine the role of Muller's ratchet on the evolution of sex in RNA viruses and report here a significant decrease in fitness due to Muller's ratchet in 20 lineages of the RNA bacteriophage phi 6. These results show that deleterious mutations are generated at a sufficiently high rate to advance Muller's ratchet in an RNA virus and that beneficial, backward and compensatory mutations cannot stop the ratchet in the observed range of fitness decrease. [TOP OF PAGE]

  19. APPLICATION OF DIRECT PLAQUE ASSAY FOR DETECTION AND ENUMERATION OF BACTERIOPHAGES OF BACTEROIDES-FRAGILIS FROM CONTAMINATED WATER SAMPLES. Cornax, R., Morinigo, M.A., Paez, I.G., Munoz, M.A., Borrego, J.J. (1990). Appl. Environ. Microbiol. 56:3170-3173. Application of direct plaque assay for detection and enumeration of bacteriophages of Bacteroides fragilis from contaminated-water samples.The direct double-agar-layer plaque assay for the detection and enumeration of specific bacteriophages of Bacteroides fragilis from contaminated-water samples was performed. Several factors that affect the methods, such as conditions of the bacterial culture, composition of the assay medium, addition of divalent cations, and decontamination techniques applied to the sample, were evaluated. The results obtained show that the direct assay technique provided to be more efficient than the most-probable-number technique. A higher recovery of bacteriophages was obtained from 17 of 24 samples with the direct assay. The two methods only showed similar results from samples with a low degree of pollution. [TOP OF PAGE]

  20. Ecophysiology of bacteriophage S5100 infecting Halobacterium cutirubrum. Daniels, L.L., Wais, A.C. (1990). Appl. Environ. Microbiol. 56:3605-3608. Increasing salinity reduces burst size and increases the latent period of infection of Halobacterium cutirubrum by lytic bacteriophage S5100. Cells become reversibly and persistently infected at saturation-level concentrations of NaCl. We propose that high salinity provides a natural refuge for sensitive host bacteria and that phage S5100 acts as a scavenger, proliferating when host viability is threatened by dilution of the environment. [TOP OF PAGE]

  21. Temperate bacteriophages and lysogeny in lactic acid bacteria. Davidson, B.E., Powell, I.B., Hillier, A.J. (1990). FEMS Microbiol. Rev. 87:79-90. [TOP OF PAGE]

  22. BACTERIOPHAGE TYPING OF RHIZOBIUM-LEGUMINOSARUM INFECTING CALIFORNIA NATIVE CLOVERS. DENIS-ARRUE, R., HARDING, E.E. (1990). Abstracts of the Annual Meeting of the American Society for Microbiology 90:256 [TOP OF PAGE]

  23. INFLUENCE OF ANIONIC DETERGENTS SDS AND ALKYLBENZOLSULFONATE ON ADSORPTION AND TRANSPORT BEHAVIOR OF SEVERAL ENTEROTROPIC VIRUSES IN SOIL UNDER STIMULATED CONDITIONS. Dizer, H. (1990). Zentralblatt fuer Hygiene und Umweltmedizin 190:257-274. Influence of anionic detergents SDS and alkylbenzolsulfonate on adsorption and transport behavior of several enterotropic viruses in soil under stimulated conditions.The adsorption of poliovirus 3, coxsackievirus B1, and coliphage f2 on soil from an irrigation field loaded for years with waste water and sandy soil from an aquifer was investigated under the influence of two anionic detergents, sodium dodecylsulphate (SDS) and alkylbenzolsulphonate (ABS). The investigation was carried out through batch and column experiments under simulated conditions. The concentrations of both detergents found generally in surface water (0,2-10 mg/l) had no effect on the adsorption of tested viruses. The concentration of 100 mg/l was the lowest intensity that led to an impaired adsorption of viruses on the sediments. The desorbing effect of SDS was relatively higher than ABS. Both detergents gave rise to a desorption and migration of viruses. Especially in soil from an irrigation field the effect was stronger at pH 7.2 than at pH 5.1. Despite low concentrations of detergents in surface water, such procedures as bank filtration, waste water irrigation for the enrichment of groundwater, and the use of sewage sludge on agricultural fields or forest grounds can cause an accumulation of detergents or their metabolites which impairs the binding of viruses to sediments. Therefore, the danger occurrence of a groundwater contamination with enteroviruses should be considered in those sectors. [TOP OF PAGE]

  24. THE PRESENCE OF BACTERIAL VIRUS IN GROUNDWATER AND TREATED DRINKING WATER. Dutka, B.J., Palmateer, G.A., Meissner, S.M., Janzen, E.M., Sakellaris, M. (1990). Environmental Pollution 63:293-298. The presence of bacterial virus in groundwater and treated drinking water.Ten raw urban well water samples and twelve water samples collected from distribution lines after the well waters were treated were examined for bacteriological and coliphage/bacteriophage populations. The raw well waters were found to contain <1/100 ml total coliforms and fecal streptococci, but they all contained varying concentrations of coliphage and bacteriophage. The treated waters were all found to have <1 total coliforms and fecal streptococci per 100 ml with the exception of one treated water sample from Community C. However, even though the treated water samples contained free and total chlorine levels varying from 0.05 to 1.5 ppm, they were all found to contain usually greater amounts of coliphage and bacteriophage than the raw well waters. [TOP OF PAGE]

  25. CONTROL OF SOFT ROT ERWINIAS WITH BACTERIOPHAGES. Eayre, C.G., Concelmo, D.E., Bartz, J.A. (1990). Phytopathology 80:994 [TOP OF PAGE]

  26. Eimeria species which infect the chicken contain virus-like RNA molecules. Ellis, J., Revets, H. (1990). Parasitology 101 Pt 2:163-169. There is increasing support for the presence of viruses and virus-like particles inside protozoan cells. This study describes viral-like RNA molecules that have been detected in two species of Eimeria that infect the chicken. The RNA molecule identified in E. maxima has been characterized: subcellular fractionation studies have shown that the RNA is present in the cytoplasm, probably as an abundant ribonucleoprotein that is insensitive to RNAse A treatment. Electron microscopy has demonstrated that this RNA molecule is double stranded. In addition, all E. maxima strains examined so far contain this RNA molecule. [TOP OF PAGE]

  27. Parasite Communities. Patterns and Processes. Esch, G.W., Bush, A.O., Aho, J.M. (1990). Chapman and Hall, New York.[TOP OF PAGE]

  28. Adsorption of viruses by diatomaceous earth coated with metallic oxides and metallic peroxides. Farrah, S.R., Preston, D.R. (1990). In Grabow, W.O.K., Morris, R., and Botzenhart, K. (eds.), HEALTH-RELATED WATER MICROBIOLOGY 1990. Diatomaceous earth coated with oxides of aluminium, calcium, iron, magnesium, or manganese were not found to be useful for recovering viruses from water. The oxide coatings were not stable water or only adsorbed viruses in small volumes of water. Further modification of coating of magnesium oxide to make magnesium peroxide produced a modified diatomaceous earth that efficiently adsorbed viruses in water. Filters containing 3.5 g of diatomaceous earth adsorbed an average of greater than 90% of MS2, polio 1, coxsackie B5, and echo 5 in tapwater at approximately pH 8.5, even after 100 liters of tapwater had passed through the filters. From 15 to 40% of MS2 or enteroviruses could be recovered from tapwater using filters containing diatomaceous earth coated with magnesium peroxide. [TOP OF PAGE]

  29. Isolation of an LC-specific Escherichia coli bacteriophage. Fralick, J.A., Diedrich, D.L., Casey Wood, S. (1990). J. Bacteriol. 172:1660-1662. We isolated an OmpF-specific bacteriophage whose host range mutant, SQ108h2, requires the presence of the Lc porin for its attachment and which can be used to screen or select for Lc- defective mutants among Escherichia coli K-12 strains lysogenic for the PA-2 converting phage. [TOP OF PAGE]

  30. Transfection of the Giardia lamblia double-stranded RNA virus into Giardia lamblia by electroporation of a single-stranded RNA copy of the viral genome. Furfine, E.S., Wang, C.C. (1990). Mol. Cell. Biol. 10:3659-3663. [TOP OF PAGE]

  31. Biological and physical dosimeters for monitoring solar UVB light. Furusawa, Y., Suzuki, K., Sasaki, M. (1990). J. Radiat. Res. 31:189-206. [TOP OF PAGE]

  32. Prey-derived signals regulating duration of the developmental growth phase of Bdellovibrio bacteriovorus. Gray, K.M., Ruby, E.G. (1990). J. Bacteriol. 172:4002-4007. The filamentous elongation typical of growth-phase cells of the predatory bacterium Bdellovibrio bacteriovorus is mediated by regulatory signals that are derived from the prey cell itself. These signals regulate the differentiation of growth-phase cells into the attack phase and appear to be required for continued filamentous growth by prey-dependent wild-type bdellovibrios and their prey-independent mutant derivatives alike. Using a prey-independent bdellovibrio strain, we have developed an assay for the detection and quantification of the growth-extending signal activity present in extracts of prey cells. This prey-derived regulatory activity was shown to be independent of its nutritional contribution to the bdellovibrios and was found to occur in heat-stable, proteinlike compounds of a variety of native molecular weights within the soluble fraction of extracts from both gram-negative and gram-positive bacteria. [TOP OF PAGE]

  33. Inability of a bacteriophage pool to control beef spoilage. Greer, G.G., Dilts, B.D. (1990). Int. J. Food Microbiol. 10:331-342. The biological control of beef spoilage, with a bacteriophage (phage) pool, was evaluated under simulated retail conditions. A pool of seven phages was selected with the potential to lyse 78% of 86 Pseudomonas test strains. Subsequent host range studies with 1023 pseudomonads from three meat species (beef, pork, lamb) and five abattoirs showed that 585 (57.2%) isolates were susceptible to the phage pool. Depending on bacterial origin, bacterial sensitivity to lysis by the phage pool varied from 25 to 72%. When added to ribeye steaks, the phage pool produced a significant reduction in Pseudomonas growth but this was not sufficient to produce any significant effect upon the retail shelf life of beefj. The inability of phages to control beef spoilage was not attributed to a loss of phage virulence since sufficient densities (log pfu/cm2 - 5 to 6) of virulent phage could be re-isolated from beef, 14 days after treatment. It was concluded that the efficacy of the current phage pool was limited by a narrow range of specificity. [TOP OF PAGE]

  34. EFFECT OF SEASONS ON THE PRODUCTION OF TEMPERATE PHAGES BY STRAINS OF PSEUDOMONAS-SYRINGAE AND XANTHOMONAS-CAMPESTRIS. Gvozdyak, R.I., Samoilenko, V.I. (1990). Mikrobiologicheskii Zhurnal (Kiev) 52:42-44. Effect of seasons on the production of temperate phages by strains of Pseudomonas syringae and Xanthomonas campestris.It has been established by long-term studies that a season affects isolation of temperate bacteriophages from cultures of phytopathogenic bacteria of genera Pseudomonas and Xanthomonas. Practically it is possible to isolate phages from cultures only in summer (June-August). [TOP OF PAGE]

  35. F-specific RNA bacteriophages and sensitive host strains in faeces and wastewater of human and animal origin. Havelaar, A.H., Pot-Hogeboom, W.M., Furuse, K., Pot, R., Hormann, M.P. (1990). J. Appl. Bacteriol. 69:30-37. Faeces of humans, pigs, cattle and chickens were investigated for the presence of somatic coliphages, F-specific bacteriophages and Escherichia coli strains sensitive to infection by F-specific phages. Attention was given to the possible effect of age and use of antibiotics on the prevalence of the FRNA phages and sensitive E. coli strains. Somatic coliphages were often detected in high numbers in all types of faeces. In contrast, FRNA phages were rarely detected in faeces from humans and cattle but more often in faeces from pigs and adult chickens. Samples from young chickens (with or without antibiotics) were consistently positive for FRNA phages (up to 3 x 10(6) pfu/g). F-specific RNA phages were found in substantial numbers (greater than 10(3) pfu/ml) in a variety of wastewaters: domestic, hospital, slaughterhouses and occasionally in 'grey water'. Their origin in wastewater was not clear. Strains from faeces usually belonged to serogroups I and IV. These types were also found in wastewater, as were group II and III strains. Serogroup II phages were abundant in wastewater of human origin but rare in faeces. Escherichia coli strains sensitive to infection by F-specific phages were common in faeces (overall 290/1081: 27%). No strains with fully depressed F-pilus synthesis were detected among the sensitive strains. It is concluded that the occurrence of F-specific RNA bacteriophages in water points to sewage pollution rather than faecal pollution; the mechanism of replication of these organisms in wastewater is not understood. [TOP OF PAGE]

  36. INACTIVATION OF BACTERIOPHAGE MS2 IN WASTEWATER EFFLUENT WITH MONOCHROMATIC AND POLYCHROMATIC UV LIGHT. Havelaar, A.H., MEULEMANS, C.C.E., Pot-Hogeboom, W.M., KOSTER, J. (1990). Water Res. 24:1387-1394. Inactivation of bacteriophage MS2 in wastewater effluent with monochromatic and polychromatic UV light.A model using bacteriophage MS2 for the calculation of the effective dose in u.v.-disinfection by polychromatic light from a medium pressure mercury lamp was studied. The model was based on first-order inactivation kinetics, the u.v.-absorption spectrum of MS2-RNA as the action spectrum and Lambert-Beers' law for light absorption by the effluents. The u.v.-sensitivity of the phage was calibrated with a low pressure mercury lamp; the inactivation rate constant (k) was 0.0106 m2/J, which corresponds well with previously reported data. The model fitted actual data in most experiments, although tailing effects were observed. In some experiments a different value of k was necessary to fit the actual inactivation curves, varying between 0.0077 and 0.012 m2/J. The MS2 phage was found suitable for calibration of u.v. sources. [TOP OF PAGE]

  37. NEW METHODS FOR EXTRACTION OF STREPTOMYCETE SPORES FROM SOIL AND APPLICATION TO THE STUDY OF LYSOGENY IN STERILE AMENDED AND NONSTERILE SOIL. Herron, P.R., Wellington, E.M.H. (1990). Appl. Environ. Microbiol. 56:1406-1412. New methods for extraction of streptomycete spores from soil and application to the study of lysogeny in sterile amended and nonsterile soil.A new method for the isolation and enumeration of streptomycete spores from soil was developed. This method makes use of a cation-exchange resin to disperse soil particles. It allowed the detection of 10 spores in 100 g of sterile soil, while ca. 103 could be accurately enumerated in 100 g. This method was applied to studying the fate of a marked actinophage in soil. In sterile amended and nonsterile soil, relatively high numbers of actinophages were only found during the first few days of the experiment when the hot streptomycete was in the mycelial form. Later, after sporulation, lysogens could be detected in sterile amended soil and could still be found 60 days after inoculation. Although no lysogens were found in nonsterile soil, the introduced phage could still be detected in the free state after 60 days, albeit at a low titer. [TOP OF PAGE]

  38. Influence of rhizophage on the gorwth of rhizobium-leguminosarum. HICKISH, B., AMRIR, A. (1990). Zentralblatt fuer Mikrobiologie 145:95-98. Influence of rhizobiophage on the growth of Rhizobium leguminosarum.A Rhizobiophages test on soil samples taken from plots with different crop species was carried out. Rhizobiophages were identified under legumes only. Rhizobiophages could not be dedected in Rhizobium strains from stain depots. A Rhizobium strain isolated from Vicia fabe revealed clearly inhibited growth in the presence of Rhizobiophage in the culture medium. [TOP OF PAGE]

  39. Characterization of the bacteriophages infecting marine luminous bacterium Vibrio harveyi (Kaiyosei hakko-saikin Vibrio harveyi ni kansensuru bakuteriofaji no seijo). Hidaka, T., Kobayashi, M., Arimura, S. (1990). Memoirs of the Faculty of Fisheries Kagoshima University 39:159-166. Characterization of bacteriophages infecting marine luminous bacterium Vibrio harveyi.Bacteriophages infecting marine luminous bacterium Vibrio harveyi have been isolated from seawater and fish in Kagoshima Bay [Japan], during 1980 to 1985. The eighty-five of isolated bacteriophages were divided into three groups with their lytic pattern to host bacteria. The representative three V. harveyi-phages were observed about the host range, plaque morphology, particle structure, stability, one step growth characteristics, and serological property. They are phages with a long and noncontractile tail, and also stable phages with double-stranded DNA as genetic material. The test phages varied in host range, plaque morphology, one-step growth characteristics, and serological property. These phages may provide a rapid and sensitive means of differentiating V. harveyi strains by phage typing method. [TOP OF PAGE]

  40. Evidence for the exchange of segments between genomes during the evolution of lambdoid bacteriophages. Highton, P.J., Chang, Y., Myers, R.J. (1990). Molecular Microbiology 4:1329-1340. Heteroduplexes between the DNA molecules of 12 lambdoid phages were analyzed by electron microscopy. The positions of the regions of base sequence homology between the DNA molecules divide them into 35 segments, most of which have a number of alternative forms (alleles), which in general must be functionally homologous but which differ in base sequence and length. The positions of the boundaries between segments in phage .lambda. show that each segment is probably a gene of a group of genes, and that each phage genome is a different combination of the alleles of the segments. The frequency of the occurrence of the different alleles indicates that the total number of the natural population may be small. The different combinations of alleles of separate segments, found among the phages, indicate the exchange of segments between the phages during their evolution. [TOP OF PAGE]

  41. Cloning, expression, and sequence determination of a bacteriophage fragment encoding bacteriophage resistance in Lactococcus lactis. Hill, C., MILLER, L.A., Klaenhammer, T.R. (1990). J. Bacteriol. 172:6419-6426. A number of host-encoded phage resistance mechanisms have been described in lactococci. However, the phage genome has not been exploited as a source of additional resistance determinants. A 4.5-kb BamHI-HindIII fragment of phage nck202.50 (phi 50) was subcloned in streptococcus-Escherichia coli shuttle plasmid pSA3 and introduced into Lactococcus lactis NCK203 and MG1363 by protoplast transformation. This cloned phage fragment directed a bacteriophage resistance phenotype designated Per (phage-encoded resistance). Both phi 50 and a distantly related phage, nck202.48 (phi 48), formed small plaques on strain NCK213 at a slightly reduced efficiency of plaquing on the Per+ host. The per locus was further reduced to a 1.4-kb fragment through in vitro deletion analysis. The 1.4-kb fragment was sequenced, and the Per phenotype was found to be associated with a ca. 500-bp region rich in direct and inverted repeats. We present evidence that the Per region contains a phage origin of replication which, in trans, may interfere with phage replication by titration of DNA polymerase or other essential replication factors. It was demonstrated that the Per+ phenotype is not a result of reduced adsorption or action of a restriction and modification system. Per+ activity was not detected against six independent phages which were previously shown to be sensitive to the Hsp+ mechanism. The mutually exclusive resistance mechanisms could be combined to confer resistance to both types of phages (Hsp resistant and Per resistant) in a single host. This is the first description in lactococci of a phage resistance phenotype, other than superinfection immunity, originating from a lactococcal phage genome. [TOP OF PAGE]

  42. Comparison of the action of ionizing radiation and UV-light on lambda phage. Influence on phage adsorption, DNA injection, replication, and DNA repair. Hradecna, Z., Kittler, L. (1990). Acta Virol. 34:401-409. The influence of gamma radiation, X-rays, UV-light at 254 nm and 365 nm, the latter combined with furocoumarin sensitizers has been studied on plaque forming ability, phage adsorption, DNA injection, and replication processes. UV-light (365 nm) plus furocoumarin treatment of phage particles gave rise to two types of DNA crosslinks. Type I crosslink corresponded to furocoumarin mediated covalent linkage between adjacent sites in opposite strands of the double helix. Crosslink type II (hairpin crosslink) required a highly condensed DNA and corresponded to the covalent linking of adjacent sites in double helical segments of a folded DNA molecule. The relationships of the type I crosslinks to inhibition of DNA replication and of the type II crosslinks to suppression of the DNA injection process are discussed. Pronounced deviations in phage inactivation have been obtained by X-ray radiation alone compared with UV-light (254 nm) pretreated and subsequently X-ray irradiated probes. The observed protective effect of the latter was described in terms of an inducible repair mechanism. The same protection has been observed by combination of gamma radiation with a sublethal UV-light (254 nm) dose. [TOP OF PAGE]

  43. Isolation of Bdellovibrio bacteriovorus. Hu, L., Liu, B.Y. (1990). Chinese Journal of Microbiology and Immunology (Beijing) 10:95-98. Bdellovibrio bacteriovorus (Bd.b) is a unique gram- negative bacteria living on other bacteria. They were isolated from aquatic and terrestrial intestinal ecosystems, but have not yet been successfully isolated from human being by previous workers. With tape water double-layer agar medium, we have successfully isoalted 8 strains of Bd.b. out of 86 stool samples from Beijing youngsters. Checking up with plaque characteristics, Gram stain, phase and electron microscopy, the strains which we isolated were found to possess typical biological characteristics of Bd.b. We defined their optimal cultural conditions. The optimal growth was achieved at 37.degree. C, pH7.0, in aerobic or microaerophilic environment. Our strains behaved as parastitic and bacteriolytic and is able to lyse a variety of gram-negative bacteria (including Shigella, E. coli, Salmonella typhimurium and Vibrio cholerae) under facultative aerobic condition, and Bacteroides fragilis under micro-aerophilic condition. Infected with a simple coreal test in guinea-pig was used to evaluate their protective effect on a experimental animals. We found that the human intestinal strain of Bd.b could prevent the animal from experimental infection with pathogenic Shigella flexneri 2a. [TOP OF PAGE]

  44. PRESENCE OF CERTAIN BACTERIOPHAGES IN MOSQUITO LARVAL HABITATS INHIBITING THE LARVICIDAL ACTIVITY OF BACILLUS-THURINGIENSIS AND BACILLUS-SPHAERICUS. Hussein, M.E., Merdan, A., Abdel Razik, N.A., Morsy, S., Botros, M. (1990). Journal of Applied Entomology 109:513-519. Presence of certain bacteriophages in mosquito larval habitats inhibiting the larvicidal activity of Bacillus thuringiensis and Bacillus sphaericus.Twelve water and/or mud samples from different mosquito habitats were tested for the presence of phages specific to Bacillus spp. Thirty seven plaque morphologies were detected on B. thuringiensis H-14, B. thuringiensis Berl. B. sphaericus 1593, B. sphaericus IF-114. Samples number 1, 11, 12, 5 and 10 decreased the mortality rates of B. thuringiensis H-14 when added to the larvicidal bioassay system of Culex pipiens. Samples number 5, 11, 9, 12 and 6 inhibited the larvicidal activity of B. sphaericus. Ultrafiltrates of water samples, which harboured high numbers of the detected phages exerted more inhibition in the larvicidal potentiality of the tested entomopathogenic bacteria. [TOP OF PAGE]

  45. Isolation and propagation of phages naturally associated with the aizawai variety of Bacillus thuringiensis. Inal, J.R.M., Karunakaran, V., Burges, H.D. (1990). J. Appl. Bacteriol. 68:17-22. This study describes the isolation of a phage, using mitomycin C and u.v. light, from each of four strains (HD67, HD130, HD228 and HD248) of Bacillus thuringiensis H-serotype 7 ( var. aizawai). It also describes the isolation of two indicator strains (12.13 and HD102) for these phages (.vf.HD67, .vf.HD130, .vf.HD228 and .vf.HD248) and the ideal conditions, using these indicator strains, for maximum phage production. [TOP OF PAGE]

  46. A simple elution and reconcentration technique for viruses concentrated on membrane filters from drinking water samples. Jothikumar, N., DWARKADAS, A., KHANNA, P. (1990). Water Res. 24:367-372. A simple elution and reconcentration technique for viruses concentrated on membrane filters from drinking water samples.An optimum concentration of urea (1.5 M)-arginine phosphate (0.2:0008 M) buffer (U-APB) has been designed in this research as an eluent at pH 9.0 for effective desorption and elution of viruses from negatively charged membrane filters. The primary eluate is further reconcentrated by the precipitation of MgHPO4(s) on addition of MgCl2. The flocs are centrifuged, the pellet is dissolved in McIlvaines buffer (pH 5) and neutralized with sodium bicarbonate (8.8%) prior to assay on cell culture. The efficacy of the method has been tested at different inoculum levels and also for different volumes of water samples seeded with viruses. U-APB gives 92-100 and 88-93% recovery for Poliovirus 1 and bacteriophage, respectively, as against a 30-40% recovery of Poliovirus 1 and bacteriophage, respectively, and a meagre 30-40% recovery of Poliovirus 1 in the organic flocculation of beef extract method presently in use. Further, the eluent (U-APB) is easy to constitute and it performs elution and reconcentration of viruses without any pH adjustment. [TOP OF PAGE]

  47. Use of bacteriophages and antibiotics for prevention of acute postoperative empyema in chronic suppurative lung diseases. Kaczowski, H., Weber-Dabrowska, B., Dabrowski, M., Zdrojweicz, Z., Cwioro, F. (1990). Wiad. Lek. 43:136-141. [TOP OF PAGE]

  48. The difficulty of using coliphages as "indicators" and "index" organisms. Karst, M., Dutkiewicz, R., Hahn, T., Botzenhart, K. (1990). In Grabow, W.O.K., Morris, R., and Botzenhart, K. (eds.), HEALTH-RELATED WATER MICROBIOLOGY 1990. Different types of coliphages (T2, T4, T7, MS2 Phi X174, coliphages from surface water) were concentrated by a MgCl2 flocculation and a filtration (Virosorb 1MDS) method. Phage type as well as water quality had an influence on recovery rates of the concentration methods. None of them were superior when single phage types were used. Also various conditions had an influence on recovery rates in the direct plaque assay. Different phage aggregates are probably responsible for the range of recovery rates. Therefore it is probably not possible to standardize methods for isolating and detecting coliphages and they may be used as "indicators" or "index" organisms not at all or only in a strictly defined system. [TOP OF PAGE]

  49. Virus-like particles in an ultraoligotrophic lake on Vancouver Island, British Columbia. Klut, M.E., Stockner, J.G. (1990). Can. J. Fish. Aquat. Sci. 47:725-730. [TOP OF PAGE]

  50. Role of submicrometre particles in the ocean. Koike, I., Hara, S., Terauchi, K., Kogure, K. (1990). Nature 345:242-244. [TOP OF PAGE]

  51. [Comparative evaluation of Escherichia coli strains as markers for the study of bacteriophages]. LIBERTI, R., Bonadonna, L., Volterra, L. (1990). BOLLETTINO - SOCIETA ITALIANA BIOLOGIA SPERIMENTALE 66:479-485. The count of coliphages in polluted waters was found to be dependent on many experimental factors. The host-strain used for their enumeration is among the most important. In this paper we report a comparative investigation on the variability of counts of coliphages in sewage as a result of variations in host-strains of Escherichia coli and in methodologies. Two methods were used for enumerating them: the M.P.N. and the direct count. E. coli C, B1, Hfr and E36 consistently produced more plaques than any other host tested. [TOP OF PAGE]

  52. COMPARISON OF ESCHERICHIA-COLI STRAINS FOR THE RECOVERY OF BACTERIOPHAGES. LIBERTI, R., Bonadonna, L., Volterra, L. (1990). Bollettino Societa Italiana Biologia Sperimentale 66:479-486. Comparison of Escherichia coli strains for the recovery of bacteriophages.The count of coliphages in polluted water was found to be dependent on many experimental factors. The host-strain used for their enumeration is among the most important. In this paper we report a comparative investigation on the variability of counts of coliphages in sewage as a result of variations in host-strains of Escherichia coli and in methodologies. Two methods were used for enumerating them: the M.P.N. and the direct count. E. coli C, B1, Hfr and E36 consistently producted more plaques than any other host tested. [TOP OF PAGE]

  53. Characterization of bacteriophages and bacteria indigenous to a mixed-strain cheese starter. LODICS, T.A., Steenson, L.R. (1990). Journal of Dairy Science 73:2685-2696. Characterization of bacteriophages and bacteria indigenous to a mixed-strain cheese starter.To understand the types of phages and bacteria that coexist in a phage-carrying starter, we characterized isolates from milk fermented by a commercial mixed-strain culture. The bacterial population was 62% Lactococcus lactis ssp. cremoris, 19% Lactococcus lactis ssp. lactis biovar. diacetylactis, 2% Lactococcus lactis ssp. lactis, 16% Leuconostoc cremoris, and 1% unknown species. Plasmid analyses indicated 24 groups of L. lactis ssp. cremoris strains, 4 groups of L. lactis ssp. lactis biovar. diacetylactis, 1 group of L. lactis ssp. lactis, and 1 group of Leuc. cremoris. Fermentation times and sensitivity to outside phages varied between strains. Seven phages were isolated from the starter. Six attacked L. lactis ssp. cremoris strains, and one attacked L. lactis ssp. lactis biovar. diacetylactis. Three L. lactis ssp. cremoris phages crossreacted on starter hosts, and their DNA patterns were similar after restriction endonuclease digestion and agarose gel electrophoresis. Electron microscopy and DNA/DNA hybridization revealed two distinct small isometric phage types. One type attacked L. lactis ssp. cremoris and had a collar, whiskers, hexagonal tail-base structure, and 151-nm long tail. The other type attacked L. lactis ssp. lactis biovar. diacetylactis, had a tail fiber and a 215-nm long tail. Bacteria within and between plasmid groups demonstrated various degrees of resistance to these phages. Although lytic phages and sensitive hosts were both present, the mixed-strain culture functioned as a fast acid-producing starter. [TOP OF PAGE]

  54. Bacteriophage typing of Listeria species. Loessner, M.J., Busse, M. (1990). Appl. Environ. Microbiol. 56:1912-1918. A bacteriophage typing scheme for differentiating Listeria isolates from dairy products and various other foodstuffs was developed. Sixteen selected phages isolated from both environmental sources and lysogenic strains were used for typing and, according to their lytic spectra, divided into four groups. Thus far, 41 distinct patterns of lysis were seen when this set was used in typing 57 defined reference strains, representing all five confirmed species and 16 serotypes in addition to 454 Listeria isolates of primarily foodborne origin. Overall, typability was 84.5%; i.e., a strain was lysed by at least one phage at 100x routine test dilution. Strains belonging to serovar 3 were mostly resistant to lysis by the phages employed. The results were highly reproducible, as determined in retyping trials several weeks later. Some phages isolated from environmental sources showed a wider lytic spectrum than did those isolated from lysogenic strains. In accordance with this, the phages were found in different clusters within a computer-generated linkage map. Species specificity and serovar specificity of the lytic reaction were not found. None of the phages was able to lyse strains of Listeria grayi, Listeria murrayi or Jonesia denitrificans. This phage typing system may provide important information for a means of recognizing and eliminating sources of contamination by Listeria spp. within dairy plant equipment. [TOP OF PAGE]

  55. ASSESSMENT OF STANDARD METHODS FOR THE DETECTION OF FECAL CONTAMINATION IN THE MONITORING OF STREAMS IN AN EQUATORIAL RAIN FOREST. Loh, C.L., Zain, H.M., Ngeow, Y.F., Wang, C.W., Ho, Y.C. (1990). Malayan Nature Journal 44:77-84. Assessment of standard methods for the detection of fecal contamination in the monitoring of streams in an equatorial rain forest.Faecal coliform, faecal streptococci, hydrogen sulphide producing bacteria and coliphages were detected in the waters of the rivers and springs tested in the Kinchin River Basin, Pahang, Malaysia. With the exception of the coliphage test, the other tests did not appear to the suitable for the detection of human contamination of pristine waters. [TOP OF PAGE]

  56. PROPERTIES OF THE TRANSDUCING PHAGE M1 OF RHIZOBIUM-MELILOTI. MALEK, W. (1990). Journal of Basic Microbiology 30:43-50. Properties of the transducing phage M1 of Rhizobium meliloti.A temperate phage M1, infective towards some R. meliloti strains, was isolated from soil taken from local fields. It is morphology, host range, transducing ability and the locations of restriction endonuclease cleavage sites on the genomes were determined. Phage M1 was classified as belonging to B BRADLEY's group bacteriophages because of the hexagonal outlines of its head and its long, flexible and non-contractible tail. The molecular weight of phage DNA was estimated to be 54.1 .+-. 1 kilobases (kb) and it corresponded to the value expected for capsid size.sbd.70 nm. Phage M1 carries out general transduction and forms stable lysogens with the R. meliloti strain L5.30. [TOP OF PAGE]

  57. Isolation and characterization of bacteriophage PM2 from Aeromonas hydrophila. Merino, S., Camprubi, S., Tomas, J.M. (1990). FEMS Microbiol. Let. 56:239-244. PM2 is an Aeromonas-specific bacteriophage isolated on A. hydrophila strain AH-3. The bacteriophage receptor for this phage was found to be the lipopolysaccharide (LPS), specifically a low-molecular weight LPS fraction (LPS-core oligosaccharides). Mutants resistant to this phage were isolated and found to be devoid of LPS O-antigen and altered in the LPS-core. No other outer-membrane (OM) molecules appeared to be involved in phage binding. [TOP OF PAGE]

  58. MICROBIAL DEPURATION OF THE BIVALVE MYTILUS-EDULIS. MESQUITA, M.M.F. (1990). Revista Brasileira de Biologia 49:933-942. Microbial depuration of the bivalve Mytilus edulis.This study aims to contribute to a better understanding of the depuration process, used in some countries as the main form of commercial treatment of bivalves harvested from microbially contaminated waters. The elimination ratios of three bacterial indicator groups (Escherichia coli, faecal streptococci, and sulphite-reducing spore-forming clostridia) and two bacteriophage groups (somatic coliphage and F-specific phage) were compared in naturally contaminated mussels. The elimination ratios of some of these indicators were equally compared in mussels previously subect to artificial contamination. The effect of environmental factors such as contamination dose and exposure period in the efficency of depuration was also studied. A long period of exposure to contaminants, even at a low dose, has shown to cause a marked retention of part of the bacteriophage in mussel tissues during depuration. The same is not true for the bacteria. The results obtained confirm the little reliability of E. coli as sanitary indicator and encourage the use of other indicators herein tested since these are apparently better models of the microbial pathogens behaviour in depurating bivalves. Suggestions are made to decrease the risk of bivalve consumption at the present moment. [TOP OF PAGE]

  59. BACTERIOPHAGES AS VIRAL MODELS IN STUDIES OF WATER AND SHELLFISH QUALITY. Mesquita, M.M.F.D. (1990). Revista Brasileira de Biologia 49:923-932. Bacteriophages as viral models in studies of water and shellfish quality.Bacterial groups traditionally used as indicators of the presence of pathogenic bacteria in effluents, polluted aquatic environments and shellfish, although reasonably efficient for this purpose, as enteric virus indicators are far from being ideal. This fact together with the non-existence of routine methods for detection and enumeration of epidemiologically significant viruses, have caused a search for alternative solutions. In recent years, some bacteriophage groups (coliphages and F-specific phages) due to their similarity with viruses, have been the subject of many studies and they may in the future be a solution, even if partial, for the indicator problem. Their utility, limitations and potential as models of viral behaviour in various situations are discussed here. Some suggestions for further research are equally made. [TOP OF PAGE]

  60. Cyanophages which impact bloom-forming cyanobacteria. Monecue, R.L., Phlips, E.J. (1990). J. Aquat. Plant. Manage. 28:92-97. Not sure if following constitutes abstract: Describes isolation of cyanophages that affect L. wollei and two other cyanobacteria. Futher studies: see Monegue and Phlips (1991). (quoted from http://nosferatu.cas.usf.edu/chemistry/info_research_resources/ies/LYNGBYA.html). [TOP OF PAGE]

  61. Receptor-recognizing proteins of T-even type bacteriophages. The receptor-recognizing area of proteins 37 of phages T4. Montag, D., Hashemolhosseini, S., Henning, U. (1990). J. Mol. Biol. 216:327-334. [TOP OF PAGE]

  62. A new temperate cyanophage NP-1T lysogenizing cyanobacterial cultures belonging to the genera Nostoc and Plectonema. Muradov, M., Cherkasov, G.V., Akhmedova, D.U., Khalmuradov, A.G. (1990). Mikrobiologiya 59:1038-1045. A new temperate cyanophage NP-1T growing on Nostoc and Plectonema cyanobacterial cultures is described. Cyanophages of the NP type are widespread in Uzbekistan water basins. The cyanophage has a hexagonal head on a plane with a distance of 78 nm between the facets, but lacks a distinctly differentiated tail. Its adsorption takes 2.5 to 3 h. The lytic cycle takes 30 h with 14 h for the latent period. The phage yield is about 350 particles per infected cell. The DNA has 72 mol.% G + C. The mean contour length is 14.4 .mu.m and the molecular mass of DNA calculated in terms of its length is 28 MDa. When the cyanophage interacts with the host culture, lysogenic clones resistant to the cyanophage appear. [TOP OF PAGE]

  63. Comparative study of NP-IT cyanophages, which lysogenize nitrogen-fixing bacteria of the genera Nostoc and Pleconema (Russian?). Muradov, M.M., Cherkasova, G.V., Akhmedova, D.U., Kamilova, F.D., Mukhamedov, R.S., Abdukarimov, A.A., Khalmuradov, A.G. (1990). Mikrobiologiya 59:819-826. Comparative characteristics of NP-1T cyanophages causing lysis of nitrogen-fixing Nostoc and Plectonema cultures.The strain specificity of NP-1T cyanophages causing lysis of Nostoc and Plectonema cultures was exerted as differences in the time of formation and in the morphology of plaques. The specificity weas confirmed by the data of restriction analysis using the EcoRV enzyme that hydrolysed the DNA of the cyanophages to yield a different number of fragments. [TOP OF PAGE]

  64. Comparative study of NP-IT cyanophages, which lysogenize nitrogen-fixing bacteria of the genera Nostoc and Pleconema (English). Muradov, M.M., Cherkasova, G.V., Akhmedova, D.U., Kamilova, F.D., Mukhamedov, R.S., Abdukarimov, A.A., Khalmuradov, A.G. (1990). Microbiology (translation of Mikrobiologiya) 59:558-563. Comparative characteristics of NP-1T cyanophages causing lysis of nitrogen-fixing Nostoc and Plectonema cultures.The strain specificity of NP-1T cyanophages causing lysis of Nostoc and Plectonema cultures was exerted as differences in the time of formation and in the morphology of plaques. The specificity weas confirmed by the data of restriction analysis using the EcoRV enzyme that hydrolysed the DNA of the cyanophages to yield a different number of fragments. [TOP OF PAGE]

  65. Cyst formation in Bdellovibrio soil strain at parasitism on Microciclys major bacterial culture. Nikitina, E.S. (1990). Izvestiya Akademii Nauk SSSR Seriya Biologicheskaya 309-311. Cysts of Bdellovibrio have been found in old lysates of two- component Bdellovibrio/M. major cultures. They are considered as a resulting form of the parasite. Morphology of the cyst has been described. [TOP OF PAGE]

  66. COMPETITIVENESS OF ALFALFA RHIZOBIA IN THE PRESENCE OF A BACTERIOPHAGE. NOVIKOVA, N., I, SIMAROV, B., V (1990). Doklady Vsesoyuznoi Ordena Lenina i Ordena Trudovogo Krasnogo Znameni Akademii Selskokhozyaistvennykh Nauk Imeni V I Lenina 29-31. Competitiveness of alfalfa rhizobia in the presence of a bacteriophage.Data were presented on the capacity of Rhizobium meliloti strains to form nodules on alfalfa roots. The probability of inoculation with a phage-resistant strain increases by 10-30 times in the presence of a phage. It is recommended that specially-selected bacteriophages be used for eliminating undesirable Rhizobium stains. [TOP OF PAGE]

  67. RELATIONSHIP BETWEEN YERSINIA BACTERIOPHAGES AND BACTERIOPHAGES ISOLATED FROM SEWAGE. NOVOSEL'TSEV, N.N., MARCHENKOV, V., I, Sorokin, V.M., KRAVTSOV, A.N., DEGTYAREV, B.M. (1990). Molekulyarnaya Genetika Mikrobiologiya i Virusologiya 18-21. Relationship between Yersinia bacteriophages and bacteriophages isolated from sewage.The bacteriophage designated RD2 has been isolated from the sewage in Rostov-on-Don city and studied. The morphology of bacteriophage particles and the biological properties of the bacteriophage make it related to the plague bacteriophage isolated by D'Errel. The molecular masses of the compared bacteriophages are almost identical being 26,4 .+-. 0,4 Md for RD2 and 24,7 .+-. 0,2 Md for D'Errel bacteriophage. The DNAs of the bacteriophages share 80% of homology and possess 15 nonhomologous regions scattered along the genomes. The phages are serologically related. The DNAs of both bacteriophages give the similar pattern of hydrolysis by restriction endonuclease EcoRV, but have the different sensitivity to many other restriction endonucleases. The protein spector of bacteriophage RD2 contains 18 polypeptides (11 minor ones), while the one of D'Errel bacteriophage contains 7 polypeptides similar in molecular mass with the polypeptides of RD2. The bacteriophage RD2 cannot be considered one of the plague causative agents of bacteriophages since the region where it has been isolated has a long epidemiological and epizootical record of absence of plague. [TOP OF PAGE]

  68. LYTIC ACTIVITY OF YERSINIA-PESTIS PHAGE P SEROVAR 3. Novosol'tsev, N.N., Marchenkov, V.I., Kravchenko, A.N., Valentsev, V.E., Tinker, L.A. (1990). Zhurnal Mikrobiologii, Epidemiologii i Immunobiologii 12:15-18. Lytic activity of Yersinia pestis phage P, serovar 3.The lytic activity of plague phage II, serovar 3, with respect to 1,800 bacterial strains has been studied: 760 Yersinia pestis strains, 262 Y. pseudotuberculosis strains, 252 Y. enterocolitica strains, 166 Escherichia coli strians, 90 Shigella strains and 270 strains of other species. The phage has been found to lyze 81.8% of Y. pestis strains, 1 Y. pseudotuberculosis strain and 1 Y. enterocolitica strain. The representatives of other 19 bacterial species have proved to be resistant to the phage. Though having a wide range of action within Y. pestis, the phage does not lyze most of the strains of the causative agent of plague, isolated in certain natural foci. This fact offers promise for using the phage for the differentiation of Y. pestis. [TOP OF PAGE]

  69. Interactions between the soil-borne bacteriophage Fo-1 and Pseudomonas spp. on sugarbeet roots. O'Sullivan, M., Stephens, P.M., O'Gara, F. (1990). FEMS Microbiol. Ecol. 68:329-334. [TOP OF PAGE]

  70. Dynamic interactions of Pseudomonas aeruginosa and bacteriophages in lake water. Ogunseitan, O.A., Sayler, G.S., Miller, R.V. (1990). Microb. Ecol. 19:171-186. The persistence and interaction between newly isolated strains of Pseudomonas aeruginosa and resident bacteriophages indigenous to a freshwater environment was monitored over 45 days in lake water microcisms. The interaction between susceptible and resistant bacteria with pure phage (UT1) particles or a mixed phage population (M1) was investigated by following temporal changes in host density, phage-to-bacteria ratio (PBR), and the appearance of apparent prophage carriers within the host population. Decay rates of the phage (UT1) ranged form 0.054 hour- 1 in natural water to 0.027 hour-1 in filtered lake water. About 45% of sensitive bacteria incubated with phase UT1 were pseudolysogenic within 12 hours of incubation in natural lake water. This process was delayed until 72 hours in the sterile lake water control, suggesting that host-phage interaction is promoted in the presence of a viable natural microbial community. Phage UT1 appeared to stabilize the density of host bacteria in lake water at a level of 104 colony-forming units (cfu) ml-1. Bacterial coexistence with the mixed phage (M1) population resulted in an oscillating equilibrium with the pBR stabilizing at about 3. The presence of extraneous homoimmune phages appeared to be detrimental to the stability of the pseudolysogens, which were maintained at a lower population density than prophage-free cells in lake water containing the mixed phage (M1) population. [TOP OF PAGE]

  71. Viruses of protozoan parasites. Patterson, J.L. (1990). Exp. Parasitol. 70:111-113. [TOP OF PAGE]

  72. VIRUS TRANSPORT AND SURVIVAL IN SATURATED AND UNSATURATED FLOW THROUGH SOIL COLUMNS. Powelson, D.K., Simpson, J.R., Gerba, C.P. (1990). Journal of Environmental Quality 19:396-401. Virus transport and survival in saturated and unsaturated flow through soil columns.Water with entrained disease-causing virus entering soil normally passes through water-saturated and unsaturated regions before reaching the groundwater. The effects of saturated and unsaturated flow on the survival and transport of a virus, MS-2 bacteriophage, were compared. The viruses were added to well water and applied to soil columns 0.052 m in diameter and 1.05 m long. The soil material was Vint loamy fine sand (a sandy, mixed, hyperthermic Typic Torrifluvent) mixed with recent alluvium. Samples of the soil water were taken daily at 0.20, 0.40, and 0.80 m depths through porous stainless steel samplers and at 1.05 m from the percolate leaving the column. For saturated flow the virus concentrations reached the influent concentration is less than two pore volumes (PV). From unsaturated flow the concentrations remained at levels much lower than the influent, ranging from 27% of inflow at 0.20 m (18 PV) to 5% at 1.05 m (3.3 PV). At the end of the experiments soil samples from each depth were assayed to determine virus adsorption to the soil. The average distribution coefficient of the unsaturated columns, 0.27, indicates very little adsorption. The number balance showed that only 39% of the unsaturated flow virus were accounted for. It appears that under unsaturated flow conditions enhanced inactivation of this virus occurs. [TOP OF PAGE]

  73. TISSUE DISTRIBUTION OF A COLIPHAGE AND ESCHERICHIA-COLI IN MUSSELS AFTER CONTAMINATION AND DEPURATION. Power, U.F., Collins, J.K. (1990). Appl. Environ. Microbiol. 56:803-807. Tissue distribution of a coliphage and Escherichia coli in mussels after contamination and depuration.Experiments were undertaken to determine the tissue distribution of Escherichia coli and a coliphage after contamination of the common mussel (Mytilus edulis). Mussels were contaminated with high levels of feces-associated E. coli and a 22-nm icosahedral coliphage over a 2-day period in a flowing-seawater facility. After contamination, individual tissues were carefully dissected and assayed for E. coli and the coliphage. Contaminated mussels were also analyzed to determine the tissue distribution of the contaminants after 24- and 48-h depuration periods. The majority of each contaminant was located in the digestive tract (94 and 89% of E. coli and coliphage, respectively). Decreasing concentrations were found in the gills and labial palps, foot and muscles, mantle lobes, and hemolymph. Our results indicate that contamination above levels in water occurred only in the digestive tract. Contaminated mussels were depurated in a commercial-scale recirculating UV depuration system over a 48-h period. The percent reductions of E. coli occurred in the following order: digestive tract, hemolymph, foot and muscles, mantle lobes, and gills and labial palps. The percent reductions of the coliphage were different, occurring in the following order: hemolymph, foot and muscles, gills and labial palps, mantle lobes, and digestive tract. Our results clearly demonstrate that E. coli and the coliphage are differentially eliminated from the digestive tract. The two microorganisms are eliminated at similar rates from the remaining tissues. Our results also clearly show that the most significant coliphage retention after depuration for 48 h is in the digestive tract. Thus, conventional depuration practices are inappropriate for efficient virus elimination from mussels. [TOP OF PAGE]

  74. Viral mortality of marine bacteria and cyanobacteria. Proctor, L.M., Fuhrman, J.A. (1990). Nature 343:60-62. [TOP OF PAGE]

  75. EFFICIENCY OF REMOVAL OF COLIFORMS FECAL COLIFORMS AND COLIPHAGES IN THE TUBLI SEWAGE TREATMENT PLANT BAHRAIN. Qureshi, M.A., Qureshi, A.A. (1990). Water Res. 24:1459-1462. Efficiency of removal of coliforms, fecal coliforms and coliphages in the Tubli Sewage Treatment Plant, Bahrain.Total coliforms, fecal coliforms and coliphages in the raw sewage were detected in high numbers during the months averaging a maximum temperature of 20.degree. C. The secondary and tertiary effluents show a 99-100% removal of the three indicators of fecal pollution. A direct correlation between the fecal coliforms and coliphages suggests that coliphages alone may be used as an indicator for the presence of pathogenic bacteria in contaminated waters. [TOP OF PAGE]

  76. The incidence of Bdellovibrio spp. in man-made water systems: coexistence with legionellas. Richardson, I.R. (1990). J. Appl. Bacteriol. 69:134-140. Bdellovibrios have been isolated from surface waters but there are no reports of its occurrence in mains water supplies. One hundred and thirty five water samples from 81 sources were examined for the presence of Bdellovibrio bacteriovorus and Legionella spp. Bdellovibrios were isolated by a double-layer agar technique with two strains of Legionella pneumophila serogroup 1 as the host organisms. Bdellovibrio spp. were isolated from 57.8% and Legionella spp. from 9.5% of the samples. The two species occurred together in 4.4% of samples. The incidence of Bdellovibrio spp. and its occurrence with legionellas in man-made water systems is discussed. [TOP OF PAGE]

  77. Characterization of insertion sequence IS946, an Iso-ISS1 element, isolated from the conjugative lactococcal plasmid pTR2030. ROMERO, D.A., Klaenhammer, T.R. (1990). J. Bacteriol. 172:4151-4160. The self-transmissible plasmid pTR2030 mobilized nonconjugative heterologous cloning vectors pGK12 (Cmr Emr) and pSA3 (Emr) at frequencies of 10(-5) to 10(-6) per input donor. Transconjugants harbored a 51- or 58-kilobase (kb) plasmid not found in the parental strains that cotransferred at high frequency with Cmr Emr and pTR2030-encoded phage resistance (Hsp+) in second-round matings (10(-1) per input donor). Restriction endonuclease mapping and DNA-DNA hybridization identified the 51- to 58-kb plasmids as pTR2030::vector cointegrates. Examination of four cointegrates indicated that pGK12 and pSA3 had inserted within two locations on pTR2030. Resolution of the cointegrates generated vector derivatives containing a 0.8-kb insert of pTR2030 DNA. Restriction analyses of several resolution plasmids indicated that the 0.8-kb element had inserted into various positions within pGK12 and pSA3 and in certain cases had inactivated the Cmr or Emr marker of pGK12. A conjugative mobilization assay demonstrated that the 0.8-kb element, designated IS946, mediated transpositional recombination. Nucleotide sequence determination identified IS946 as an 808-base-pair (bp) insertion sequence sharing ca. 96% homology with lactococcal insertion sequence ISS1. IS946 differed by 27 and 31 bp from ISS1S and ISS1T, respectively, and in 2 of 226 amino acids in the deduced sequence of the putative transposase. IS946 has perfect 18-bp terminal inverted repeats, identical to ISS1, and similarly generated 8-bp direct repeats of the target site upon insertion. [TOP OF PAGE]

  78. Abortive phage infection and restriction/modification activities directed by pTR2030 determinants are enhanced by recombination with conjugal elements in lactococci. ROMERO, D.A., Klaenhammer, T.R. (1990). Journal of General Microbiology 136:1817-1824. Abortive phage infection and restriction/modification activities directed by pTR2030 determinants are enhanced by recombination with conjugal elements in lactococci.The recombinant plasmid pTK6 is composed of a 13.6 kb fragment from pTR2030 encoding phage resistance determinants for restriction/modification (R+/M+) and abortive phage infection (Hsp+) cloned into shuttle vector pSA3 (erythromycin resistance, EMr). Conjugal matings were performed to mobilize pTK6-encoded markers from Lactococcus lactis subsp. lactis MMS362 and MG1363. EMr transconjugants were recovered at 10-6 per input donor and harboured pTK6 or recombinant plasmids not found in either parental strain. The recombinant plasmids (pTRK78 and pTRK79) encoded EMr, Hsp+ and R+/M+, and transferred at high frequency in second-round matings. Mobilization of pTK6 from the otherwise plasmid-free donor, L. lactis MG1363, confirmed the presence of a conjugal element in this strain. Phage resistance in transconjugants containing pTRK78 and pTRK79 was markedly enhanced over pTK6-directed Hsp+ and R+/M+. In L. lactis LM2345 transconjugants, a reduction in plaque size was accompanied by a significant decrease in the efficiency of plaquing for phages c2 (10-2 to 10-6) and p2 (<10-9). L. lactis NCK203 transconjugants containing pTRK78 or pTRK79 exhibited an additional 100-1000-fold reduction in the plaquing efficiency of .vphi.48 (10-4 to 10-5) over pTK6 imposed restriction (10-2). Increased resistance to phage was a consequence of the physical interaction of pTR2030-derived sequences on pTK6 with a conjugal element resident in the donor strains. [TOP OF PAGE]

  79. PSEUDOMONAS-AERUGINOSA TRANSPOSABLE BACTERIOPHAGES D3112 AND B3 REQUIRE PILI AND SURFACE GROWTH FOR ADSORPTION. RONCERO, C., Darzins, A., CASADABAN, M.J. (1990). J. Bacteriol. 172:1899-1904. Pseudomonas aeruginosa transposable bacteriophages D3112 and B3 require pili and surface growth for adsorption.Pseudomonas aeruginosa transposable bacteriophages D3112 and B3 were found to require pili for infection. Seventy mutants of P. aeruginosa PAO selected by resistance to D3112 or B3 were also resistant to the phage not used in the selection and suggested that the receptors of these two phages are identical. Of five resistant mutants examined, all were defective in the production of pili and did not adsorb either phage. P. aeruginosa PAK strains altered in pilus expression, such as hyperpiliated or nonpiliated mutants, adsorbed the phage but were not productively infected, implying that an additional host function was required for infection. The cell-associated lipopolysaccharide was not required for D3112 or B3 infection, since mutants deficient in O side-chain and core biosynthesis were still capable of adsorption and productive infection. This is in contrast to Escherichia coli mutator phages Mu and D108, which are dependent on lipopolysaccharide for adsorption. The P. aeruginosa phages absorbed only to cells grown on soil media or in lipid media supplemented with agents that increase the macroviscosity, such as polyvinylpyrrolidone. Adsorption time course studies of D3112 and B3 using cells grown in solid media revealed similar but not identical adsorption patterns. These studies suggested that expression of the D3112 and B3 cell receptor is induced by growth on solid media. [TOP OF PAGE]

  80. CLONING OF PHAGE RESISTANCE GENES FROM LACTOCOCCUS-LACTIS-SSP-CREMORIS KH. Sanders, M.E., SHULTZ, J.W. (1990). Journal of Dairy Science 73:2044-2053. Cloning of phage resistance genes from Lactococcus lactis ssp. cremoris KH.A 17.5-kb plasmid conferring restriction and modification-type phage resistance in Lactococcus lactis ssp. cremoris KH was transformed into Lactococcus lactis LM0230 and cloned onto an origin of replication-deficient vector directly into L. lactis. Expression of phage resistance was seen in L. lactis but not in E. coli. A restriction map was generated of the cloned plasmid, and the region encoding phage resistance was localized by insertional inactivation and deletion analysis. [TOP OF PAGE]

  81. Transduction of linked chromosomal genes between Pseudomonas aeruginosa strains during incubation in situ in a freshwater habitat. Saye, D.J., Ogunseitan, O.A., Sayler, G.S., Miller, R.V. (1990). Appl. Environ. Microbiol. 56:140-145. Both transduction of single chromosomal loci and cotransduction of closely linked loci were observed between lysogenic and nonlysogenic strains of Pseudomonas aeruginosa in a freshwater habitat. Transductants were recovered at frequencies of 10- 6 to 10-5 transductants per CFU. Transductants of lysogenized strains were recovered 10- to 100-fold more frequently than were transductants of nonlysogenic parents. Lysogens are thus capable of introducing phages which mediate generalized transduction into the natural microbial community and serving as recipients of transduced DNA. It would appear that lysogeny has the potential of increasing the size and flexibility of the gene pool available to natural populations of bacteria. The ability to generate and select new genetic combinations through phage-mediated exchange can be significant in the face of a continually changing environment and may contribute to the apparent fitness of the lysogenic state in natural ecosystems. [TOP OF PAGE]

  82. Bacteriophages in Helicobacter pylori. Schmid, E.N., von Recklinghausen, G., Ansorg, R. (1990). J. Med. Microbiol. 32:101-104. Bacteriophages in different stages of maturation were found in thin sections of a clinical isolated of Helicobacter (Campylobacter) pylori. Mature phage heads measured 70 .times. 60 nm and the tail at least 120 nm. Lysogeny was maintained during subculture on blood agar for more than 3 months after isolation from a gastric biopsy. [TOP OF PAGE]

  83. Changes of traits in a bacterial population associated with protozoal predation. Shikano, S., Luckinbill, L.S., Kurihara, Y. (1990). Microb. Ecol. 20:75-84. [TOP OF PAGE]

  84. Bacteriophage-enhanced sporulation: Comparison of the spore converting bacteriophages PMB12 and SP10. Silver-Mysliwiec, T., Bramucci, M.G. (1990). J. Bacteriol. 172:1948-1953. [TOP OF PAGE]

  85. Characteristics of phage abortion conferred in lactococci by the conjugal plasmid pTR2030. Sing, W.D., Klaenhammer, T.R. (1990). J. Gen. Microbiol. 136:1807-1815. [TOP OF PAGE]

  86. A SIMPLE MEMBRANE FILTER METHOD TO CONCENTRATE AND ENUMERATE MALE-SPECIFIC RNA COLIPHAGES. Sobsey, M.D., SCHWAB, K.J., HANDZEL, T.R. (1990). American Water Works Association Journal 82:52-59. A simple membrane filter method to concentrate and enumerate male-specific RNA coliphages.The purpose of this study was to develop and evaluate a simple membrane filter method for concentrating and enumerating F-specific coliphages in raw and finished drinking water wtih a view to using these phages as a viral indicator. The method developed was field-tested by determining the concentrations of F-specific coliphages in several souce waters and comparing them with concentrations of fecal indicator bacteria. The results suggest that the new membrane filter method for enumerating F-specific coliphages sould be useful for assessing fecal contamination of natural and treated waters. Additional studies are needed to determine whether these coliphages are reliable indicators of enteric viruses in water. [TOP OF PAGE]

  87. USE OF ECOLOGICALLY HARMLESS PESTICIDES IN CROP INDUSTRY ITS STATUS PROBLEMS AND PROSPECTS REPORT 2. PATHOGEN OF FUNGAL AND BACTERIAL DISEASES. SOKOLOV, M.S. (1990). Agrokhimiya 124-145. [TOP OF PAGE]

  88. CHARACTERIZATION OF PHI-GA1 AN INDUCIBLE PHAGE PARTICLE FROM BREVIBACTERIUM-FLAVUM. SONNEN, H., Schneider, J., KUTZNER, H.J. (1990). Journal of General Microbiology 136:567-572. Characterization of .phi.GA1, an inducible phage particle from Brevibacterium flavum.Eighteen related strains of Arthrobacter, Brevibacterium and Corynebacterium were used as indicator strains in an attempt to isolate corynephages from a large number of soils and from waste-water samples. Although no phages capable of producing plaques were isolated, one of the indicator strains used, Brevibacterium flavum ATCC 14067, was lysogenic for the inducible phage .vphi.GA1. This phage was not observed to form plaques on any of the strains tested. .vphi.GA1 is of B1-morphotype with a linear double-stranded DNA genome of 48.1 kb with cohesive ends; a restriction map is presented. [TOP OF PAGE]

  89. Stochastic three species systems. Sridhara, R., Watson, R. (1990). Journal of Mathematical Biology 28:595-608. This paper examines the coexistence of three species. In particular, stochastic models for (i) two predators and one prey, (ii) two prey and one predator, and (iii) a prey, a predator and a parasite to the predator are considered. It is found that coexistence is possible in each case. A large population approximation is developed which enables accurate description of the long run behaviour of stochastic models. [TOP OF PAGE]

  90. Infection of phytoplankton by viruses and reduction of primary productivity. Suttle, C.A., Chan, A.M., Cottrell, M.T. (1990). Nature 347:467-469. Natural marine waters contain roughly 106 to 109 virus particles per ml, yet their role in aquatic ecosystems and the organisms that they infect remain largely unknown. Electron microscopy has been used to study interactions between viruses and their hosts, focusing mainly on pathogens to prokaryotic organisms. The authors demonstrate that viral pathogens infect a variety of important marine primary producers, including diatoms, cryptophytes, prasinophytes and chroococcoid cyanobacteria. Also, addition to sea water of particles in the 0.002-0.2 &micro;m size range, concentrated from sea water by ultrafiltration, reduced primary productivity (14C-bicarbonate incorporation) by as much as 78%. Results indicate that in addition to grazing and nutrient limitation, infection by viruses could be a factor regulating phytoplankton community structure and primary productivity in the oceans. [TOP OF PAGE]

  91. CONTROL OF TOBACCO BACTERIAL WILT BY AN AVIRULENT STRAIN OF PSEUDOMONAS-SOLANACEARUM M4S AND ITS BACTERIOPHAGE. TANAKA, H., NEGISHI, H., MAEDA, H. (1990). Annals of the Phytopathological Society of Japan 56:243-246. [TOP OF PAGE]

  92. CHARACTERIZATION OF A TEMPERATE ACTINOPHAGE MPPHIWR-1 CAPABLE OF INFECTING MICROMONOSPORA-PURPUREA ATCC 15835. TILLEY, B.C., MEYERTONS, J.L., LECHEVALIER, M.P. (1990). J. Indust. Microbiol. 5:167-182. Characterization of a temperate actinophage, MPphiWR-1, capable of infecting Micromonospora purpurea ATCC 15835.A temperate actinophage was isolated from soil using the gentamicin-producing microorganism, Micromonospora purpurea ATCC 15835 as host. The characterization of the phage represents the initial step in its development as a cloning vector. The phage isolated, MPphiWR-1, formed red- to purple-pigmented turbid plaques. Cells isolated from these plaques were resistant to superinfection with lytic mutants of MPphiWR-1. Southern blots of genomic DNA from a resistant culture showed that MPphiWR-1 integrated into the host genome. The phage was UV- or Mitomycin C-inducible. The integration, resistance to superinfection and inducibility indicated a lysogenic relationship with the host. Using MPphiE-RCPM, a lytic derivative, the phage host range was demonstrated to include members of three genera: one species each of Ampullariella and Catellatospora, and 12 species of Micromonospora. The phage belonged to Ackerman's B1 morphotype having an isometric head and a flexible noncontractile tail. The density of the phage was 1.525 g/cc. Restriction site mapping demonstrated that the phage DNA was 57.9 kb long and had cohesive ends. Using EDTA enrichment, viable mutants with deletions of at least 3.5 kb were isolated and mapped. Phage adsorption, sensitivities and plating efficiency were investigated. Non-liposome PEG-mediated transfection was demonstrated. [TOP OF PAGE]

  93. STUDIES ON PHAGE-SENSITIVITY OF SOFT ROT BACTERIA. Togashi, J. (1990). Annals of the Phytopathological Society of Japan 56:309-314. [TOP OF PAGE]

  94. Principles of Bacteriology, Virology and Immunity. Topley, W.W.C., Wilson, G.S. (1990). B.C. Decker Publishing, London.[TOP OF PAGE]

  95. HIGH DIVERSITY IN DNA OF SOIL BACTERIA. TORSVIK, V., GOKSOYR, J., DAAE, F.L. (1990). Appl. Environ. Microbiol. 56:782-787. High diversity in DNA of soil bacteria.Soil bacterium DNA was isolated by minor modifications of previously described methods. After purification on hydroxyapatite and precipitation with cetylpyridinium bromide, the DNA was sheared in a French press to give fragments with an average molecular mass of 420,000 daltons. After repeated hydroxyapatite purification and precipitation with cetylpyridinium bromide, high-pressure liquid chromatography analysis showed the presence of 2.1% RNA or less, whereas 5-methylcytosine made up 2.9% of the total deoxycytidine content. No other unusual bases could be detected. The hyperchromicity was 31 to 36%, and the melting curve in 1 .times. SCC (0.15 M NaCl plus 0.015 M sodium citrate) corresponded to 58.3 mol% G + C. High-pressure liquid chromatography analysis of two DNA samples gave 58.6 and 60.8 mol% G + C. The heterogeneity of the DNA was determined by reassociation of single-stranded DNA, measured spectrophotometrically. Owing to the high complexity of the DNA, the reassociation had to be carried out in 6 .times. SCC with 30% dimethyl sulfoxide added. Cuvettes with a 1-mm light path were used, and the A275 was read. DNA concentrations as high as 950 .mu.g ml-1 could be used, and the reassociation rate of Escherichia coli DNA was increased about 4.3-fold compared with standard conditions. C0t1/2 values were determined relative to that for E. coli DNA, whereas calf thymus DNA was reassociated for comparison. Our results show that the major part of DNA isolated from the bacterial fraction of soil is very heterogeneous, with a C0t1/2 about 4,600, corresponding to about 4,000 completely different genomes of standard soil bacteria. The reassociation curves did not follow ideal second-order reaction curves, indicating that there are several different DNA fractions coresponding to common and more rare biotypes. This means that the C0t1/2 values give only approximate and probably low values for the genome number. Some of the DNA preparations had a rapidly reassociating fraction of about 5% of the total DNA. Th e reassociation rate for this fraction was about one-third of the rate of the E. coli genome. This fraction might be a population of plasmids and/or bacteriophages. Our results indicate that the diversity of the total bacterial community in a deciduous-forest soil is so high diversity indices based on DNA heterogeneity can be determined only with difficulty. Most of the diversity is located in that part of the community which cannot be isolated and cultured by standard techniques. [TOP OF PAGE]

  96. ISOLATION AND CHARACTERIZATION OF BDELLOVIBRIO PARASITIC TO GRAM-NEGATIVE FISH PATHOGENIC BACTERIUM AEROMONAS-HYDROPHILA. Tsay, S.-S., Wang, H.H. (1990). Taiwania 35:112-126. Isolation and characterization of Bdellovibrio parasitic to gram-negative fish pathogenic bacterium Aeromonas hydrophila.One strain of bacteria parasite-Bdellovibrio was isolated from cultured fish ponds in Taiwan. This strain is able to parasitize on Aeromonas hydrophila, designated as Bdellovibrio-A-1. The morphology of host and parasite were examined by means of electron microscopy. The effect of medium composition, initial pH of medium, incubation temperature, addition of divalent cation and kinds and concentration of host bacteria on the growth of Bdellovibrio were investigated. The optimum temperature for the growth of Bdellovibrio in liquid medium was 25-29.degree. C. The optimum initial pH of medium was pH 6.5. Growth of the parasite was dependent upon the addition of Ca2+ and Mg2+. The highest lytic action of Bdellovibrio was obtained by using a higher concentration of fish pathogenic-bacteria (4 .times. 108 cells/ml) as host. [TOP OF PAGE]

  97. A new model for the penetration of prey cells by bdellovibrios. Tudor, J.J., McCann, M.P., Acrich, I.A. (1990). J. Bacteriol. 172:2421-2426. Bdellovibrio bacteriovorus 109J and most other bdellovibrios cause prey cells to round following penetration. Bdellovibrio sp. strain W does not cause rounding of the prey. Analysis of enzyme activities during the early stages of bdellovibrio attack indicated that strain W differs from most other bdellovibrios in that there is no glycanase activity produced during penetration. Likewise, heat-killed prey were penetrated normally by strain 109J, but the resulting bdelloplast did not become round and no glycanase was detected, indicating that glycanase is not essential for penetration. Peptidoglycan from prey cells penetrated by strain W was sensitive to lysozyme, but these cells were not susceptible to attack and penetration by strain 109J, indicating that peptidoglycan deacetylation is not the primary exclusion mechanism. We propose a model in which it is the peptidase activity of the bdellovibrios which allows them to breach the peptidoglycan of their prey and in which the glycanase activity exhibited by strain 109J and other bdellovibrios is responsible for the rounding of the bdelloplast. [TOP OF PAGE]

  98. ??? Tudor, J.J., McCann, M.P., Acrich, I.A. (1990). J. Bacteriol. 172:2421-2426. [TOP OF PAGE]

  99. THE EFFECTS OF CHLORINE DISINFECTION ON THE RESISTANCE OF BACTERIOPHAGE F2 IN WATER. WU, Z.-C., JIANG, X.-J. (1990). Zhonghua Yufang Yixue Zazhi 24:196-198. The effects of chlorine disinfection on the resistance of bacteriophage f2 in water.Under defined conditions, Escherichia coli bacteriophage f2 was subject to repeated disinfection by chlorine 10 times. The survival bacteriophage f2 was compared with its original strain in resistance to chlorine. Experimental results showed that bacteriophage f2 increased its resistance after chlorine disinfection. The increased resistance varied under different conditions. The higher the pH, the greater the increased resistance. The survival bacteriophage f2 maintained its increased resistance though it was passaged 10 times in nutrient broth. The reason for the increased resistance of bacteriophage f2 after chlorine disinfection was probably the chlorine-induced mutation or spontaneous chlorine-resistant mutation. [TOP OF PAGE]

  100. Bacteriophage transport through porous media, effects of pH and hydrophobicity. Yahya, M., McGuire, K., Gerba, C.P. (1990). EOS 71:1326-??? [TOP OF PAGE]

  101. Evaluation of potassium permanganate for inactivation of bacteriophage MS-2 in water systems. Yahya, M.T., Landeen, L.K., Forshoefel, N.R., Kujawa, K., Gerba, C.P. (1990). J. Environ. Sci. Hlth. A25:81-100. [TOP OF PAGE]

  102. The effect of indigenous bacteria on virus survival in ground water. Yates, M.V., Stetzenbach, L.D., Gerba, C.P., Sinclair, N.A. (1990). J. Environ. Sci. Health A25:81-100. Over one-half of the waterborne disease outbreaks in the United States are due to the consumption of contaminated ground water. Although viruses are a major cause of illness in these outbreaks, very little is known about the factors which influence how long viruses can remain infective in ground water. Experiments were conducted using several ground water samples obtained from drinking water wells to determine the effects of the naturally-occurring bacteria on the survival of coliphage MS-2 and poliovirus type 1 inoculated into the samples. [TOP OF PAGE]

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