Complete and Defective Bacteriophages of Classical Vibrio cholerae: Relationship to the Kappa Type Bacteriophage

The Classical Vibrio cholerae strain NIH 41 contains two temperate bacteriophages, designated VcA-1 and VcA-2, that are distinguished by immunity, plaque morphology, induction kinetics, and particle morphology. Both phage are serologically related to phage Kappa. However, only phage VcA-2 has the Kappa type host range and immunity. The induction kinetics and immunity patterns of Classical vibrios suggest that these strains may contain defective phage related to the phages isolated from NIH 41. Classical strain 569B releases phage-tail structures upon induction that are morphologically and serologically related to both phages VcA-1 and VcA-2. The possible reason for the defectiveness of these phages in 569B is discussed. It is concluded that complete or defective bacteriophages of the Kappa type morphology and serology are extremely prevalent in V. cholerae, regardless of biotype.     

Characterization of six Leuconostoc fallax bacteriophages isolated from an industrial sauerkraut fermentation

Six bacteriophages active against Leuconostoc fallax strains were isolated from industrial sauerkraut fermentation brines. These phages were characterized as to host range, morphology, structural proteins, and genome fingerprint. They were exclusively lytic against the species L. fallax and had different host ranges among the strains of this species tested. Morphologically, three of the phages were assigned to the family Siphoviridae, and the three others were assigned to the family Myovidae: Major capsid proteins detected by electrophoresis were distinct for each of the two morphotypes. Restriction fragment length polymorphism analysis and randomly amplified polymorphic DNA fingerprinting showed that all six phages were genetically distinct. These results revealed for the first time the existence of bacteriophages that are active against L. fallax and confirmed the presence and diversity of bacteriophages in a sauerkraut fermentation. Since a variety of L. fallax strains have been shown to be present in sauerkraut fermentation, bacteriophages active against L. fallax are likely to contribute to the microbial ecology of sauerkraut fermentation and could be responsible for some of the variability observed in this type of fermentation.     

Direct electron microscopy study on the morphological diversity of bacteriophage populations in lake plusssee

Direct electron microscopy of bacteriophages adsorbed to a carbon film without prior enrichment by specific host strains or concentration by physical or chemical methods was used to study the morphological diversity of natural bacteriophage assemblages in a North German lake. All samples contained a mixture of morphologically different tailed viruses, which were regarded as bacteriophages. Most of them had isometric heads and long noncontractile tails, belonging to morphotype B1 (Siphoviridae). In addition, members of morphotypes A1 (Myoviridae), B2 (Siphoviridae with elongated heads), and C1 (Podoviridae) were present in lower numbers. Only one cubic virus was detected, while no filamentous or pleomorphic phages were found. Up to 11 different phages per sample, and a total of 39 phages when all samples were considered together, could be distinguished by morphological criteria. The total number of phages was estimated to be on the order of 10/ml.     

Characterization of Bacillus subtilis bacteriophages

Brodetsky, Anna M. (University of California, Los Angeles), and W. R. Romig. Characterization of Bacillus subtilis bacteriophages. J. Bacteriol. 90:1655-1663. 1965.-A group of six phages, SP5, SP6, SP7, SP8, SP9, and SP13, which use the Marburg strain of Bacillus subtilis as host was characterized. These phages, referred to as group 1, were examined for the following properties: host range, plaque morphology, stability, adsorption kinetics, one-step growth characteristics, calcium requirements, serum neutralization, thermal inactivation, and inactivation by ultraviolet irradiation. Five unrelated B. subtilis phages, SP3, SP10, PBS1, SP alpha, and SP beta, were included in the studies. When first isolated, none of the group 1 phages was able to replicate efficiently on B. subtilis SB19, a mutant of the "transforming" B. subtilis 168. Host range mutants capable of growth in SB19 were isolated for all of the group 1 phages except SP13, and are designated the "star" phages (SP5* through SP9*). For characterization, SB19 was used as host for the star phages, and another B. subtilis mutant, 168B, was host for SP13.     

Some Properties of Five New Salmonella Bacteriophages

Five bacteriophages were isolated from lysogenic strains of Salmonella potdam. On the basis of plaque morphology, thermostability, serology, host range, one-step growth parameters, and phage morphology, they were divided into three groups: group A, phages P4 and P9c; group B, phages P3 and P9a; and group C, phage P10. Group A phages had a hexagonal head 55 nm in diameter with a short tail 15 nm long. These phages were particularly characterized by high thermostability, lack of serological relationship with any of the other phages, and restriction of lysis to other Salmonella strains of Kauffmann-White group C(1). Group B phages had a head identical in size and shape to that of the A phages, but they possessed a tail 118 nm long with a contractile sheath. A unique feature was the occurrence of tail fibers at the end of the core rather than at the base of the sheath. These phages were considerably less thermostable, had extended host ranges, and were serologically distinct from each other but unrelated to the A phages. The group C phage, P10, had a head identical to that of the A and B phages. It had a tail 95 nm in length, with tail fibers attached to a base plate at the end of a contractile sheath. P10 was highly sensitive to heat, lysed only smooth strains of Salmonella, and showed a degree of serological relationship to both B phages. The relationship of these phage groups to previous Salmonella phage grouping schemes is discussed.     

Bacteriophages of Bacillus polymyxa

Virulent bacteriophages of colistin--producing Bacillus polymyxa strains were studied. The phages were found to differ in lytic spectrum and were active only against strains of B. polymyxa. They did not attack other strains of the genus Bacillus. The virulent bacteriophages belong to two morphological groups differing in size. The size of the DNA of the bacteriophages of both groups is similar and ranges from 74.9 X 10(6) to 87.8 X 10(6) daltons. The cells of different B. polymyxa strains were also found to carry various defective phages which could be shown after mitomycin C induction of cell cultures. The antibacterial activity of mitomycin C induced cell lysates was not detected. Strains of B. polymyxa most probably devoid of defective bacteriophages (delysogenized) were isolated.     

Direct Electron Microscopy Study on the Morphological Diversity of Bacteriophage Populations in Lake Plußsee

Direct electron microscopy of bacteriophages adsorbed to a carbon film without prior enrichment by specific host strains or concentration by physical or chemical methods was used to study the morphological diversity of natural bacteriophage assemblages in a North German lake. All samples contained a mixture of morphologically different tailed viruses, which were regarded as bacteriophages. Most of them had isometric heads and long noncontractile tails, belonging to morphotype B1 (Siphoviridae). In addition, members of morphotypes A1 (Myoviridae), B2 (Siphoviridae with elongated heads), and C1 (Podoviridae) were present in lower numbers. Only one cubic virus was detected, while no filamentous or pleomorphic phages were found. Up to 11 different phages per sample, and a total of 39 phages when all samples were considered together, could be distinguished by morphological criteria. The total number of phages was estimated to be on the order of 10⁸/ml.     

Phages naturally associated with the aizawai variety of insect pathogen Bacillus thuringiensis and their relevance to strain identification

Of 36 strains of the ' aizawai ' variety of Bacillus thuringiensis (H-serotype 7) 16 were naturally associated with bacteriophages, 11 of which were isolated at titres of 10⁶ plaque-forming units/ml and above. These 11 phages had varied host ranges among Bacillus cereus and five strains of the ' aizawai ' variety of B. thuringiensis. Host range, plaque morphology and differences in cold lability indicated dissimilarities between the phages, which could be used taxonomically to differentiate between strains of this bacillus.     

Isolation and characteristics of new nonlysogenic bacteriophages of Pseudomonas aeruginosa

A large group of nonlysogenic bacteriophages specific for Pseudomonas aeruginosa was studied. According to their absorption characteristics and serological properties, the phages were subdivided into four groups: luminal diameter k, luminal diameter m, luminal diameter mnP78 and luminal diameter mnF82. Within each of the groups, the phages were similar in the morphology of their particles and certain physiological characteristics. The luminal diameter m phages were similar to the P. aeruginosa bacteriophage E79 in their adsorption properties and antigenic specificity. The phages of the other groups differed in the above characteristics from the known P. aeruginosa bacteriophages. The effect of some plasmids on the growth of bacteriophages luminal diameter k, luminal diameter m, luminal diameter mnP78 and luminal diameter mnF82 was studied. The growth of new bacteriophages on certain plasmid-containing strains was inhibited in some cases.     

Characterization of Xanthomonas phaseoli Bacteriophages

Ten bacteriophages for Xanthomonas phaseoli were characterized. On the basis of adsorption rates, latent period and burst size, plaque morphology, host range, efficiency of plating, ultrastructure, sensitivity to osmotic shock, streptomycin sensitivity, temperature effects on plating efficiency, and serology, the phages were separated into at least three groups. Some of the phages were infectious for Pseudomonas phaseolicola (four strains) and P. syringae (one strain) in a narrow temperature range. The taxonomic and ecological significance of this finding is discussed.     

Characterization of Six Leuconostoc fallax Bacteriophages Isolated from an Industrial Sauerkraut Fermentation

Six bacteriophages active against Leuconostoc fallax strains were isolated from industrial sauerkraut fermentation brines. These phages were characterized as to host range, morphology, structural proteins, and genome fingerprint. They were exclusively lytic against the species L. fallax and had different host ranges among the strains of this species tested. Morphologically, three of the phages were assigned to the family Siphoviridae, and the three others were assigned to the family Myoviridae. Major capsid proteins detected by electrophoresis were distinct for each of the two morphotypes. Restriction fragment length polymorphism analysis and randomly amplified polymorphic DNA fingerprinting showed that all six phages were genetically distinct. These results revealed for the first time the existence of bacteriophages that are active against L. fallax and confirmed the presence and diversity of bacteriophages in a sauerkraut fermentation. Since a variety of L. fallax strains have been shown to be present in sauerkraut fermentation, bacteriophages active against L. fallax are likely to contribute to the microbial ecology of sauerkraut fermentation and could be responsible for some of the variability observed in this type of fermentation.     

Diversity of temperate bacteriophages induced in bovine and ovine Mannheimia haemolytica isolates and identification of a new P2-like phage

The diversity of temperate bacteriophages was examined in 32 Mannheimia haemolytica, six Mannheimia glucosida and four Pasteurella trehalosi isolates. Phage particles were induced and identified by electron microscopy in 24 (75%) M. haemolytica isolates, but in only one (17%) M. glucosida and one (25%) P. trehalosi isolate. The M. haemolytica phages were relatively diverse as seven Siphoviridae, 15 Myoviridae and two Podoviridae-like phages were identified; the Myoviridae-type phages also exhibited structural variation of their tails. The bacteriophages induced in M. glucosida and P. trehalosi were of the Myoviridae type. Restriction endonuclease (RE) analysis identified nine distinct RE types among the M. haemolytica bacteriophages, providing further evidence of their relative diversity. A limited number of phages caused plaques on indicator strains and the phages exhibited a narrow host range. A subgroup of 11 bovine serotype A1 and A6 isolates contained Myoviridae-type phages of the same RE type (type A), but these differed in their abilities to infect and form plaques on the same panel of indicator strains. A P2-like phage (phiPHL213.1), representative of the RE type A phages, was identified from the incomplete M. haemolytica genome sequence. The phiPHL213.1 genome contains previously unidentified genes and represents a new member of the P2 phage family.     

Taxonomic and phylogenetic studies on a new taxon of budding, hyphal Proteobacteria, Hirschia baltica gen. nov., sp. nov

Four strains of budding, hyphal bacteria, which had very similar chemotaxonomic properties, were isolated from the Baltic Sea. The results of DNA-DNA hybridization experiments, indicated that three of the new isolates were closely related, while the fourth was only moderately related to the other three. Sequence signature and higher-order structural detail analyses of the 16S rRNA of strain IFAM 1418T (T = type strain) indicated that this isolate is related to the alpha subclass of the class Proteobacteria. Although our isolates resemble members of the genera Hyphomicrobium and Hyphomonas in morphology, assignment to either of these genera was excluded on the basis of their markedly lower DNA guanine-plus-cytosine contents. We propose that these organisms should be placed in a new genus, Hirschia baltica is the type species of this genus, and the type strain of H. baltica is strain IFAM 1418 (= DSM 5838).     

Morphology and General Characteristics of Lytic Phages Infective on Strains of <Emphasis Type="Italic">Bradyrhizobium japonicum</Emphasis>

Biological characteristics of three isolated phages (SR1, SR2, and SR3) lytic against three Bradyrhizobium japonicum strains were studied. These phages had no cross-infectivity among the host strains. Phage morphology indicates that they belonged to Siphoviridae (long noncontractile tail; SR1 and SR2) and Podoviridae (short tail; SR3) classes of bacteriophages. Lytic cycle of phages studied under identical conditions showed a distinct adsorption rate (67.3–99.1%), latent period (150–300 min), rise period (60–150 min), and burst size (110–200 pfu/cell). Stability in liquids and inactivation by osmotic shock, thermal, and ultraviolet irradiation were also distinct in this heterogeneous phage group. Influence of soil factors such as temperature, soil moisture, soil pH, and degree of phage adsorption to the soil on phage survival was determined. Major percent of free infective phages were obtained after desorption of phages from soil. Overall, temperature appeared to be the most important parameter affecting rhizobiophage survival in the soil.     

Characterisation of major biological properties of Bordetella bacteriophages

The main biological properties (morphology of negative colonies, parameters of adsorption and single development cycle) of B. pertussis and B. bronchiseptica phages, isolated spontaneously and by induction with mitomycin C, were studied. To compare these characteristics, one B. parapertussis indicator strain was used, and the experiments were carried out under identical conditions. Highly active sera were obtained with the use of complete Freund's adjuvant. B. pertussis phages isolated from the strains of different serovars were serologically related, but not identical, and differed in their constant characterizing their rate of neutralization with homologous antisera. The adsorption of the phages on homologous strains was more intensive than on the cells of B. parapertussis indicator strain. However, the authors failed to observe the further development of the phages in the host cells.     

Classification of 17 newly isolated virulent bacteriophages of Pseudomonas aeruginosa

Seventeen virulent bacteriophages specific to Pseudomonas aeruginosa strains were isolated by screening various environmental samples. These isolated bacteriophages were grouped based on results obtained from restriction fragment analysis of phage genomes, random amplification of polymorphic DNA (RAPD) typing, morphology observations under transmission electron microscope, and host range analysis. All 17 bacteriophages are double-stranded DNA viruses and can be divided into 5 groups based on DNA restriction profiles. A set of 10-mer primers was used in RAPD typing of phages, and similar conclusions were obtained as for restriction fragment analysis. One phage was randomly selected from each of the 5 groups for morphology observations. Four of them had an icosahedral head with a long contractile tail, belonging to the Myoviridae family, and one phage had an icosahedral head with a short tail, thereby belonging to the Podoviridae family. Host range experiments were conducted on 7 laboratory strains and 12 clinical strains of P.?aeruginosa. The results showed that 13 phages had the same infection profile, killing 8 out of 19 tested P.?aeruginosa strains, and the remaining 4 phages had different and unique infection profiles. This study highlights the diversity of bacteriophages specific to P.?aeruginosa in the environment.     

明永冰川融水中一株裂解性低温噬菌体的分离及特征

【目的】高山冰川是一类独特的生态系统,本研究探索从明永冰川地区分离和培养低温菌噬菌体,并对其特征进行研究。【方法】利用已分离的低温菌为宿主,采用"双层平板法"从明永冰川融水中分离纯化低温菌噬菌体;对噬菌体及其宿主进行电镜形态观察,并进行噬菌体基因组限制性酶切片段长度多态性分析、衣壳蛋白组成分析及噬菌体生理特征研究。【结果】从明永冰川融水中分离获得一株裂解性低温噬菌体,命名为MYSP03(Mingyong Flavobacterium Siphoviridae Bacteriophage),其宿主菌MYB03鉴定为Flavobacterium菌株。噬菌体MYSP03为长尾型,无囊膜,头部具典型的正多面体立体对称结构,直径约72 nm;尾管长约240 nm,直径约10 nm;4℃时具侵染活性,在4℃-20℃范围内均可产生边缘清晰、透明的噬菌斑,最适感染温度约10℃,pH耐受范围较广,最适感染pH约9.4,对氯仿不敏感,基因组为双链DNA,大小约66 kb。     

Molecular evidence for the lysogenic state of microorganisms belonging to the genus Bordetella and characterization of Bordetella parapertussis temperate bacteriophage 66(2.2)

A new bacteriophage phiK of microorganisms belonging to the genus Bordetella was isolated from cells of the earlier characterized strains 66(2-2) (1 and 2) obtained upon phage conversion of B. parapertussis 17903 cells by B. pertussis bacteriophage phi134. Bacteriophage phiK is identical to previously described Bordetella bacteriophages phiT, phi134, and phi214 in morphology and some biological properties but has a permuted genome different from all other phages. DNA of bacteriophage phiK is not integrated in the chromosome of B. parapertussis 17903, similar to DNA of bacteriophages phiT, phi134, and phi214 that are not integrated into B. pertussis and B. bronchiseptica chromosomes, but may be present in a small part of the bacterial population as linear plasmids. Sequences homologous to DNA of bacteriophage phiK were detected in the chromosome of strain 66(2-2) (1 and 2) and in chromosomes of all tested strains B. pertussis and B. bronchiseptica. Prophage integration in chromosomes of microorganisms of the genus Bordetella may vary in different bacterial strains and species. An assumption about abortive lysogeny of B. parapertussis bacteria for phiK phage and of B. bronchiseptica for closely related phages phiT, phi134, and phi214 has been advanced. The possibility of involvement of B. pertussis insertion sequences in the formation of the chromosomal structure in 66(2-2) convertants and in phage genomes is considered.     

An Attempt at Phage Typing in the Genus Serratia

S ummary : The present report gives the results of the effect of 10 bacteriophages of Serratia marcescens on 107 strains of the genus Serratia . The phage S103 was the most effective (80% strains lyzed), and the phage PK the least (12% strains lyzed). Only 13 strains were resistant to all the phages studied. The majority of the strains of the genus studied could be allocated to one of seven groups on the basis of their sensitivity to the phages.     

Characterization of Escherichia coli donor-specific RNA-containing bacteriophages

The biological properties of 9 clones of Ri bacteriophages isolated from sewage water in 1981 were studied. On the basis of the activity of Ri phages with respect to E. coli donor-specific strains K12, the type of negative colonies, the ultrastructure of the virion and its sizes, adsorption on the pili of host cells, the latent period, the amount of harvest obtained from one infected cell, the clones under study were classified with small spherical RNA-bacteriophages. The neutralization of Ri phages with antiphage sera to standard phages f2 and fr made it possible to classify them with the first serological group and to divide them into 3 subgroups.