Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Lysogeny”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources
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↗
PubMedDate not supplied

[Functional organization of prophage and lysogeny in Erwinia carotovora with participation of a temperate bacteriophage ZF40].

Functional organization of a prophage of the temperate bacteriophage ZF40 of Erwinia carotovora subsp. carotovora which includes its immunity and inducibility as well as its effect on the host phenotype. It was established that the prophage ZF40 forms several different states in E. carotovora which are distinguished by the indices of spontaneous and lysogenic induction. In contrast to other prophages, including the lambdoid ones, the prophage ZF40 is capable to establish cytoplasmic overimmunity which protects the lysogenic system from superinfection by virulent mutants or other homoimmune bacteriophages. An increase of sensitivity of ZF40-lysogens to killing activity of colicino-like carotovoricin (CCTV) and destabilization of defective lysogeny, or resistant MCTV-prophages are related to the phenomenon of the phage lysogenic conversion of E. carotovora.

Bacteriocins↗
PubMed1984

[Lysogeny studies of Vibrio cholerae NAG].

To establish the presence of phages specific for V. cholerae NAG, 673 strains, 166 water samples from ponds and sewage and 674 fecal samples from patients with acute intestinal diseases have been studied; as a result, 54 phage races have been isolated. The occurrence of true lysogeny in V. cholerae NAG has been found to be infrequent (0.9-10% among newly isolated strains). Pseudolysogeny has been detected in 0.75% of the strains under study. Of the total number of truly lysogenic strains of V. cholerae NAG, 10% have been found to carry V. cholerae phages of types I, III, V, VII, IX. The possibility of the simultaneous existence of V. cholerae phages and V. cholerae NAG phages in the environment has been shown. Of the isolated phages, 45 races have no serological relationship with V. cholerae phages, while possessing specific lytic activity with respect to V. cholerae NAG.

Acute Disease↗
PubMedDate not supplied

[Lysogeny among "Yersinia frederiksenii", "Y. kristensenii" and "Y. intermedia"].

We described the lysogeny among new species of Yersinia: Y. frederiksenii (47 strains), Y. kristensenii (57 strains) and Y. intermedia (133 strains). We found that 6.3% of the strains of Y. frederiksenii, 3.5% of Y. kristensenii and 2.2% of Y. intermedia were lysogenic for bacteriophages active on Y. enterocolitica (mainly the phenotypes incriminated in human pathology) and less frequently lysogenic for some strains of Y. frederiksenii, Y. kristensenii and Y. intermedia. One bacteriophage, isolated from the strain Y. frederiksenii 7291, should allow to discriminate between Y. enterocolitica phagovar IXa (susceptible) and IXb (resistant), and between the strains of Y. enterocolitica belonging to phagovar Xz and serovar 5 either biovar 1 (sometimes susceptible) or biovar 3 (always resistant).

Lysogeny↗
PubMedDate not supplied

[Lysogeny in Bacillus thuringiensis].

Different strains of several Bacillus thuringiensis serotypes were analyzed for lysogeny. All of the studied cultures released phages. Phages with an isometric capsid and a noncontractible tail were detected in preparations of the majority of the cultures. The growth of a group of related phages was limited upon lysogenization of the galleriae serotype with Tm2 phage isolated from a culture of the morrisoni serotype. The physico chemical parameters of the phages were determined.

Bacillus thuringiensis↗
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↗
PubMed1967

Typing of nontypable staphylococci by lysogeny.

Strains of coagulase-positive staphylococci which were nontypable with the routine typing set of phages could be typed by lysogeny with phage-propagating strains as indicators and with ultraviolet induction. About 10% of the strains could be typed without induction. About 36% of them could be typed by this method when ultraviolet irradiation was used as an inducing agent. The phage groups from which the majority of the nontypable staphylococci originated were easily identified by this method of typing.

Bacteriolysis↗
PubMed1983

[Lysogeny and lysogenic conversion in methylotrophic bacteria. II. Lysogenic conversion in facultative methanol-assimilating Acetobacter strains].

The lysogenic state of the methylotrophic strain Acetobacter MB 58/1 is completely demonstrated by curing and lysogenization experiments. During these investigations we found that some phenotypic characteristics are modified by the presence or loss of the prophage MO 1. It could be shown that changes of the serological behaviour, the adsorption of the phages and the sensitivity against oxytetracycline are caused by lysogenic conversion. The phenotypic alterations of the bacterial cells induced by the phage genome are the result of modifications of the lipopolysaccharide structures on the cell surface. In the case of oxytetracycline resistance, interactions between the modified lipopolysaccharide structures and specific transport proteins of the cell membranes must be assumed.

Acetobacter↗
PubMed1980

Further physical characterization of deletion and substitution mutants affecting the control of lysogeny in bacteriophage P2.

A deletion of phage P2, del6 (L.E. Bertani, 1980), thought to remove the structural gene int, and a deletion/substitution, vir94, thought to remove genes int, C and cox, were mapped by electron microscopy, using the heteroduplex technique. Four independent deletion/substitution mutations, all affecting the regulatory region of P2, were compared in all possible combinations with the same technique: two showed sequence homology in their substitution DNA. The results confirm the model proposed for the origin of these mutants, analogous to that for the origin of transducing variants in phage lambda, but suggest in first approximation that the exchange between the P2 DNA and the chromosome of the host bacterium may occur at several different bacterial sites. A map of the regulatory region of P2, based on all data available from the study of deletions and insertions, is presented.

Chromosome Deletion↗