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At least 19 recordsLinked to original sources
PubMed1975

[Chemical induction of lysogeny of Staphylococcus aureus (author's transl)].

Concerning the chemical induction of lysogeny of Staphylococcus aureus only little is known. Therefore, we performed induction experiments on 43 Staph, aureus strains using nine mutagenic substances and 15 chemotherapeutics. Only three of the nine mutagenic substances (beta-propiolacton, nitrosoguanidin and mitomycin C) and six of the 15 chemotherapeutics (penicillin G, ampicillin, cephalothin, nebacetin, novobiocin and nalidixie acid) showed inducing effects. Our results demonstrated furtheron that the lysogeny inducing ability is dependent on strains and substances used.

Anti-Bacterial Agents↗
PubMedDate not supplied

[Lysogeny of Rhizobium japonicum and the sensitivity of these cultures to phages isolated from soil].

Twenty cultures of Rhizobium japonicum of various origin were tested for lysogeny using a cross technique with a preliminary UV induction and without it as well as by electron microscopy. None of the cultures was found in the lysogenic state. Phages active against Rh. japonicum were detected in four soil samples on which soybean plants were grown; 27 phages were isolated by the enrichment method and 3 phages without enrichment. The phages were capable of lysis of only Rh. japonicum cultures and differed in the spectrum of lytic action. Some of them were very specific: 9 phages caused lysis of only one among the 28 tested cultures, and 10 phages lysed 2 cultures. Phages with a broad spectrum of lytic action induced lysis of 7-9 cultures. Some of the phages isolated from soils of different type were identical and some were similar in the spectrum of lytic action. Among 28 cultures of Rh. japonicum, 8 cultures were sensitive to all of the 30 phages isolated from soil and 2 cultures were sensitive to most of the phages; the remaining cultures were sensitive to 1-8 phages. Phages and cultures have been selected which can be used for experimental preparation of lysogenic systems and further studies of lysogeny in Rh. japonicum.

Bacteriophage Typing↗
PubMed1975

The nature and incidence of lysogeny in Mycobacterium fortuitum.

Ten of 28 strain of Mycobacterium fortuitum (ranae) were found to be associated with bacteriophage; three were pseudolysogenic, one liberated a phage that lysed a sensitive indicator strain, two liberated morphologically complete phages that did not lyse any of the strains used in this study and four liberated morphologically defective phages. The lysogenic and defectively lysogenic strains showed anomalies in cultural, biochemical and antigenic properties and in susceptibility to superinfecting phages. In view of the high frequency of lysogeny found in M. fortuitum, the role of bacteriophage in the variation of properties, including pathogenicity, of mycobacteria of greater clinical importance merits further consideration.

Bacteriolysis↗
PubMed1992

Lysogeny and bacteriocinogeny in Xenorhabdus nematophilus and other Xenorhabdus spp.

Induction by mitomycin or high-temperature treatment resulted in the production of bacteriocins and phages in both phases of Xenorhabdus nematophilus A24, indicating lysogeny. Phage DNA purified from X. nematophilus A24 hybridized to several fragments of DraI-digested A24 chromosomal DNA, confirming that the phage genome was incorporated into the bacterial chromosome. Bacteriocins and phages were detected in cultures of most other Xenorhabdus spp. after mitomycin or high-temperature treatment. Xenorhabdus luminescens K80 was not lysed by these treatments, and no phages were seen associated with this strain. However, bacteriocins were detected in limited quantities in all Xenorhabdus cultures, including X. luminescens K80, without any induction. X. nematophilus A24 bacteriocins were antagonistic for other Xenorhabdus species but not for A24 or other strains of X. nematophilus.

Bacteriocins↗
PubMed1975

Chloramphenicol stimulation of lysogeny by lambda regulatory mutants.

Inhibition of protein synthesis in Escherichia coli by amino acid starvation or chloramphenicol addition increases the frequency of lysogeny by lambda phage two- to fourfold. Lambda cIII mutants, which normally lysogenize at very low frequencies, lysogenize at very high frequencies in the presence of chloramphenicol.

Bacterial Proteins↗
PubMed1975

Altered DNA synthesis in a mutant of Salmonella typhimurium that channels bacteriophage P22 toward lysogeny.

Pox-1, a mutant of Salmonella typhimurium, strongly channels P22 toward lysogeny. Viral DNA synthesis in this slow-growing mutant is delayed to a greater extent than viral protein synthesis. The relative enhancement of c2 repressor synthesis results in much higher repressor/DNA synthesis ratios in Pox-1 than in wild-type cells. This probably accounts for the high frequency of lysogenization.

DNA Replication↗
PubMedDate not supplied

[Lysogeny in heat-tolerant hydrocarbon-oxidizing actinomycetes of species Actinomyces griseomycini].

Six strains of thermophilic hydrocarbon-oxidizing Actinomyces griseomycini were tested for lysogeny. The lysogenic state was detected in the four strains and their phages were isolated. The phages isolated from the three strains were virulent and cause lysis of the host culture. All isolated phages were specific and did not cause lysis of other actinomycetes species. However, the phages had different activity towards the six studied strains of Actinomyces griseomycini. One phage induced lysis only of its indicator culture, other phages caused lysis of four strains, including those two from which no phage was isolated. All phages produced negative colonies of identical morphology. The morphology of their particles was also the same. The phages induced cross-resistance and were characterized by thermoresistance.

Actinomyces↗
PubMedDate not supplied

[The lysogeny of Vibrio parahaemolyticus of serovar O4:K12].

Lysogeny has been first established in strains of parahemolytic vibrios of serovar O4:K12. Moderate phages belonged to morphological group IV by home A. S. Tikhonenko's classification and were presented by one serological type. No correlation has been revealed between sensitivity to moderate phages of parahemolytic vibrios and specificity of "O"- or "K"-serotypes.

Gastrointestinal Diseases↗
PubMed1976

[Lysogeny in Pasteurella multocida].

Studied was the possibility of lysis-producing factors (the phenomenon of lysogeny) with 59 strains of Pastuerella multocida isolated in Bulgaria, Cuba, and Czechoslovakia. It was found that eleven of them were lysogenic in terms that a total of 12 bacteriophage strains were isolated from them; one of them yielded 2 phages. Established were three different indicator strains of Pasteurella multocida-97, SHD, and R-II--by means of which 3 different groups of P. multocida phages were isolated. The latter were stabilized and allowed to multiply up to 10(11) phage particles per 1 cc through continuous passaging, and they could be be stored at + 4 degrees C. In accordance with the host strain for multiplying the isolated P. multocida phages were divided into three different groups: phages 3, 4, 5, 6, 22, and Sl fell into group II, and phages 1075 and S-2--to group III.

Animals↗
PubMed1978

[Study of lysogeny in Bacillus thuringiensis and B. cereus].

Forty-eight strains of Bacillus thuringiensis and 12 strains of B. cereus were treated with ultraviolet light and mitomycin C. The former agent was the more effective inducer. Bacillus thuringiensis produces at least seven different phage particles with long, non-contractile tails. The frequencies of lysogeny and polylysogeny are 83 and 25% respectively. Morphologically defective phages occur in 25% of strains, whereas five of them produce low molecular-weight bacteriocins. One strain of B. cereus harbors "killer-particles." There is no apparent correlation between the presence of phage-like particles, phage senstivity, and serotypes, biotypes, or the origin of B. thuringiensis strains.

Bacillus cereus↗
PubMed1977

Phage-typing of Salmonella weltevreden based on lysogeny. I. The phage-typing system.

All of the 1070 strains of Salmonella weltevreden tested were lysogenic, temperate phage being demonstrable in 83.9% of the strains in broth culture, 6.4% in mixed culture and the remaining 9.7% after induction by UV-irradiation and MC treatment. A phage-typing scheme for Salmonella weltevreden based on the host range of temperate phages was developed. The strains could be classified into eight groups by means of the host range of their temperate phages on six indicator strains and a ninth group, the symbiotic phages of which failed to lyse any of the indicator strains.

Bacteriophage Typing↗
PubMed1977

Phage-typing of Salmonella weltevreden based on lysogeny. II. Epidemiological usefulness of the system and geographical distribution of its phage-types.

Nine hundred and forty-six strains of Salmonella weltevreden isolated in different states of India during 1958-1974 and 124 strains from Australia, Burma, Holland, Hong Kong, New Zealand, Papua New Guinea, the Philippines, Thailand, the United States and Vietnam during 1953-1971 were phage-typed according to the phage-typing scheme described in the first part of this paper (Sood and Basu, 1977). The epidemiological incidence and geographical distribution of phage-types of Salmonella weltevreden were studied. All the phage-types were present in India, the predominant phage-types being b, d and i. Phage-type g was isolated exclusively from India. All the 14 strains from Hawaii belonged to phage-type i. Phage-type h was the most predominant phage-type in Vietnam. The 15 strains isolated from Papua New Guinea in 1965, which were supposed to have originated from a single source, belonged to 3 phage-types. Except these cultures all the available epidemiologically related strains were of uniform phage-types - a finding which establishes the epidemiological validity of the scheme.

Animals↗
PubMed1976

Site c27 in phage P22 and control of the pathway to lysogeny.

Phage P22 mutation c27 defines a site required for establishment , but not maintenance of repressor synthesis. This study confirms that P22 c27 is able to synthesize repressor if active repressor is present. An interaction involving gene products of c1 and c3 and the site c27 retards expression of the lytic genes of P22. Mutations in gene c1 eliminate the retardation of lytic gene expression, but c27 does not alleviate the retardation. These results are used to construct a model that postulates that binding of c1 and c3 products to DNA at or near c27 is sufficient to cause retardation of lytic gene expression. The functioning of c27 is contrasted to that of the analogous cy mutants of lambda. The effect of the c27 mutation upon alleviation of "cl repression" was studied in a partial revertant of Salmonella typhimurium Pox-1 in which c1 repression is exaggerated. The higher frequency of lysogenization seen in the mutant host is related to enhanced cl repression.

Base Sequence↗