98 Lactococcus lactis strains were isolated from traditional fermented milk products in Turkey tested against 60 lactococcal lytic phages to determine their resistance levels. While 82 L. lactis strains were sensitive against lactic phages at different levels, 16 L. lactis strains showed resistance to all phages tested. Types of ...
PubMed
The lactococcal abortive infection mechanisms AbiA and AbiG were introduced into Streptococcus thermophilus 4035, and a range of phages capable of infecting this host were examined for sensitivity to these mechanisms. AbiA proved effective against six phages when examined at a growth ...
Abortive infection of certain strains of Escherichia coli or Shigella dysenteriae with phages of the T-even group or with phage T5 resembles the action of colicin E1 or K on sensitive bacteria, especially in the effects on biosynthetic processes. Tests on transport systems and on adenosine triphosphate levels ...
PubMed Central
AbiV is an abortive infection protein that inhibits the lytic cycle of several virulent phages infecting Lactococcus lactis, while a mutation in the phage gene sav confers insensitivity to AbiV. In this study, we have further characterized the effects of the bacterial AbiV and its interaction ...
The abortive infection of bacteriophage T7 in Shigella sonnei D2 371-48 is characterized by a premature inhibition of phage DNA replication and nucleolytic breakdown of all phage DNA. Mutations in T7 gene 10 which are recessive to the presence of the wild-type allele can alleviate the restriction of ...
An unusual, spontaneous, phage sk1-resistant mutant (RMSK1/1) of Lactococcus lactis C2 apparently blocks phage DNA entry into the host. Although no visible plaques formed on RMSK1/1, this host propagated phage at a reduced efficiency. This was evident from center-of-infection experiments, which showed that 21% of ...
Insertional mutagenesis with pGhost9::ISS1 resulted in independent insertions in a 350-bp region of the chromosome of Lactococcus lactis subsp. cremoris MG1363 that conferred phage resistance to the integrants. The orientation and location of the insertions suggested that the phage resistance phenotype was caused by a chromosomal gene turned on by a ...
A 6.3-kb fragment from pBF61 in Lactococcus lactis subsp. lactis KR5 was cloned and found to confer an abortive phage infection (Abi+) phenotype exhibiting a reduction in efficiency of plating and plaque size for small isometric- and prolate-headed bacteriophages sk1 and c2, respectively, and to produce a 10-fold decrease in c2 ...
Thirty-six mutants of fd, a virus that infects but does not kill Escherichia coli, were isolated; 35 mutants were categorized into six complementation groups. Abortive infection with mutants in genes 1, 3, 4, 5, and 6, but not in gene 2, produced a cessation of host cell growth, generally linked to low burst size and to the formation ...
In this commentary I consider use of the term �lysis from without� (LO) along with the phenomenon's biological relevance. LO originally described an early bacterial lysis induced by high-multiplicity virion adsorption and that occurs without phage production (here indicated as LOV). Notably, this is more than just high phage ...
The natural plasmid pSRQ800 isolated from Lactococcus lactis subsp. lactis W1 conferred strong phage resistance against small isometric phages of the 936 and P335 species when introduced into phage-sensitive L. lactis strains. It had very limited effect on prolate phages of the c2 species. The ...
Various mechanisms exist that enable bacteria to resist bacteriophage infection. Resistance strategies include the abortive infection (Abi) systems, which promote cell death and limit phage replication within a bacterial population. A highly effective 2-gene Abi system from the phytopathogen Erwinia carotovora ...
... Title : GENETIC ANALYSIS OF MICROORGANISM BY MIXED INFECTION OF ACTIVE PHAGE PARTICLES AND PHAGE OR BACTERIAL DNA. ...
DTIC Science & Technology
... Title : GENETIC ANALYSIS OF MICROORGANISM BY MIXED INFECTION OF ACTIVE PHAGE PARTICLES AND PHAGE OR BACTERIALDNA. ...
The lactococcal plasmid pNP40, from Lactococcus lactis subsp. lactis biovar diacetylactis DRC3, confers complete resistance to the prolate-headed phage phi c2 and the small isometric-headed phage phi 712 in L. lactis subsp. lactis MG1614. A 6.0-kb NcoI fragment of pNP40 cloned in the lactococcal Escherichia coli shuttle vector pAM401 was found to confer ...
BackgroundPseudomonas aeruginosa causes lung infections in patients suffering from the genetic disorder Cystic Fibrosis (CF). Once a chronic lung infection is established, P. aeruginosa cannot be eradicated by antibiotic treatment. Phage therapy is an alternative to treat these chronic P. aeruginosa infections. ...
Reverse transcriptases (RTs) are RNA-dependent DNA polymerases that usually function in the replication of selfish DNAs such as retrotransposons and retroviruses. Here, we have biochemically characterized a RT-related protein, AbiK, which is required for abortive phage infection in the Gram-positive bacterium Lactococcus lactis. In ...
The bacteriophage T4 unf gene, known to be involved in the arrest of transcription from cytosine-containing DNA, is unessential except in Escherichia coli strains containing plasmid pR386. Comparative genetic and biochemical analyses of parameters of unf+ and unf- phage growth in host cells isogenic except for the presence or absence of plasmid pR386 have shown that unf gene ...
Roseobacter is a dominant lineage in the marine environment. This group of bacteria is diverse in terms of both their phylogenetic composition and their physiological potential. Roseobacter denitrificans OCh114 is one of the most studied bacteria of the Roseobacter lineage. Recently, a lytic phage (RDJLPhi1) that infects this bacterium was isolated and a ...
A new strategy for starter culture rotations was developed for a series of phage-resistant clones genetically derived from a single strain of Lactococcus lactis subsp. lactis. Phage-resistant derivatives carrying different defense systems were constructed via conjugation with various plasmids encoding abortive ...
In a series of single burst experiments, the proportion of infected cells which gave rise to small numbers of phage progeny was high when young phage particles were used for infection but low when old phage particles were used. The proportion of cells inf...
National Technical Information Service (NTIS)
Flavobacteria and their phages were isolated from Finnish freshwaters and fish farms. Emphasis was set in finding phages infecting the fish pathogen Flavobacterium columnare for further purposes as phage therapy agents. Host ranges of the flavobacterial phages varied, ...
Clustered, Regularly Interspaced Short Palindromic Repeats (CRISPR) abound in the genomes of almost all archaebacteria and nearly half the eubacteria sequenced. Through a genetic interference mechanism, bacteria with CRISPR regions carrying copies of the DNA of previously encountered phage and plasmids abort the replication of phage ...
of bacterial hosts that bacterio- phage Mu can infect, and is mediated by the phage encoded site genome. Upon replication of the bacterial chromosome the phage DNA is also replicated and passed the phage genome to extend the phage's range of infection. ...
E-print Network
Ultraviolet effects on the biological function of MS2 phage were investigated. The adsorption of MS2 phage to the host cells is not affected by ultraviolet irradiation of the phage, but the penetration of phage RNA is reduced. Hydrated uridine was detected in the RNA molecules of ultraviolet-irradiated MS2 ...
Energy Citations Database
... Abstract : Leptospirosis can cause fetal abortion in pregnant mares. The number of abortions attributed to leptospiral infection in central Kentucky ...
Phage lambda is among the simplest organisms that make a developmental decision. An infected bacterium goes either into the lytic state, where the phage particles rapidly replicate and eventually lyse the cell, or into a lysogenic state, where the phage goes dormant and replicates along with the cell. Experimental ...
... It causes abortions (90%) in sheep, cattle and goats. Epizootics ... Respiratory infection with 23% having EBO antibody and abortion and premature ...
A pteroylpolyglutamate has been found to be a constituent of all Escherichia coli T-even bacteriophages and has been characterized with regard to its oxidation state, molecular weight, origin, and location on the phage particle. The phage compound has been shown to be a dihydropteroyl penta- or hexaglutamate on the basis of its chemical and physical ...
BackgroundPhages could be an important alternative to antibiotics, especially for treatment of multiresistant bacteria as e.g. Pseudomonas aeruginosa. For an effective use of bacteriophages as antimicrobial agents, it is important to understand phage biology but also genes of the bacterial host essential for phage ...
attached phages were pelleted with the bacterial cells, only unattached phages remained in the supernatant bacterial densities because phage transmission time between cells can become shorter than virus generation lesions that form when phage are allowed to infect bacterial lawns; a single ...
density of a mutant bacterial class by limiting the in situ production of mutant phage variants. For phage). The subsequent emergence of multi-drug resistant bacterial infections has provoked a resurgence in phage therapy. Phages also tend to infect a relatively limited ...
Phage display is a high-throughput technology used to identify ligands for a given target. A drawback of the approach is the absence of PTMs in phage-displayed peptides. The applicability of phage display could be broadened considerably by the implementation of PTMs in this system. The aim of this study was to investigate the possible ...
... Phage maturation in sensitized cells was followed by plating infected streptomycin- sensitive cells in the presence of streptomycin at various stages ...
... Phage SP-19(V) maturation in sensitized cells was followed by plating infected streptomycin-sensitive cells in the presence of streptomycin at ...
... from the 13 sta ins of plague bacterio- phage were determined ... that is, the number of phage particles liberated by one infected bacterial cell ...
... between 13 strains of plague bacterio- phage and with ... particles for one * infected bacterial cell comprised ... hardly differed from the plague phages. 2 ...
The use of phages is an attractive option to battle antibiotic resistant bacteria in certain bacterial infections, but the role of phage ecology in bacterial infections is obscure. Here we surveyed the phage ecology in septicemia, the most severe type of bacterial ...
... Abstract : Spores of Bacillus subtilis infected with transducing phage SP-10 served as convenient inocula for broth cultures from which transducing ...
Phage lysis of cyanobacteria could significantly influence nutrient availability in aquatic systems. We examined the requirements of phage infection in freshwater cyanobacteria
A search for the best production conditions of lambda vir and lambda clear phages in E coli K12 and E coli C sub 6 00 infected cells respectively is presented. By keeping fixed some parameters of the process as the bacterial and phage generation times and...
A procedure was devised to separate phage DNA from the cellular one, and to analyse patterns of DNA synthesis in phage epsilon 34kc-infected cells. The results suggest the followings: De novo synthesized phage DNA are at first of linear monomer, then reco...
The following studies are under way to analyse in detail the phage-host interrelations: (a) Studies on biochemical events in cells destined to lysogeny after phage infection; (b) Determination of the site of attachment of phage genome to bacterial chromos...
Fig. 1 shows a SEM of E. coli cells with phage particles attached to the outside of cells. Fig. 2 shows a SEM of E. coli cells with disrupted cell envelopes, presumably due to phage release.
NSDL National Science Digital Library
The exposure of lambda phage to triplet acetone is studied. The triplet acetone is obtained from aerobic oxidation of isobutanal catalysed by peroxidase. A decrease of lambda phage ability to infect Escherichia coli is reported, perhaps, partially due to ...
Bacteriophage T7 is a virulent phage that infects E. coli. The seventh of the set of T phages focussed on by the Cold Spring Harbor group of phage workers in the 1940's, T7 has been the object of considerable genetic and biochemical investigation. The T7 ...
2D and 3D cryo-electron microscopy, together with adsorption kinetics assays of Cb13 and CbK phage-infected Caulobacter crescentus, provides insight into the mechanisms of infection. Cb13 and CbK actively interact with the flagellum and subsequently attach to receptors on the cell pole. We present evidence that the first interaction of the ...
2D and 3D cryo-electron microscopy, together with adsorption kinetics assays of ?Cb13 and ?CbK phage-infected Caulobacter crescentus, provides insight into the mechanisms of infection. ?Cb13 and ?CbK actively interact with the flagellum and subsequently attach to receptors on the cell pole. We present evidence that the first interaction of the ...
? phage binds to E. Coli's lamB protein and injects its DNA into the cell. The phage quickly replicates and after a latent period the bacteria bursts, emitting mature phages. We developed a mathematical model based on the known physical events that occur when a ? phage infects an E.Coli cell. ...
NASA Astrophysics Data System (ADS)
The therapeutic potential of bacteriophage (phage) in a mouse model of acute B. cenocepacia pulmonary infection was assessed. Phage were administered by either intranasal (i.n.) inhalation or intraperitoneal (i.p.) injection. Bacterial density, macrophage inflammatory protein-2 (MIP-2), and tumor necrosis factor-? (TNF?) levels were ...
... perfringens was detected In an ileus case. It occasionally is cultured from infections of the uterus after childbirth, and abortion. Ac- ...
