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PubMed1979

Isolation, homogeneity, and properties of core particle from pyocin R1.

By a mild alkaline treatment of pyocin R1, the core particle was released from the contracted sheath. After sucrose density-gradient centrifugation, core-rich fractions were treated with anti-sheath serum and by a second density-gradient centrifugation, purified core particles were isolated. Homogeneity of the preparation was confirmed by observation under the electron microscope, immuno-precipitation reaction, and sucrose density-gradient centrifugation. The core particle exhibited a sedimentation coefficient of 37S. The quaternary structure of the core consists of a single kind of subunit protein with a molecular weight of 18,000. No contamination by other proteins was detected by SDS-disc electrophoreses. Amino acid analysis revealed that the core is rich in glycine, alanine, valine, leucine, aspartic acid (or asparagine), glutamic acid (or glutamine), and serine. This amino acid composition bears some resemblance to that of T-even bacteriophage tail-core.

Amino Acids↗
PubMed1983

The effect of defocusing on the electron microscopic image of the extended particle of pyocin R1.

The effect of defocusing on the electron microscopic image of the extended particle of pyocin R1 was examined with the aid of optical diffraction. The results show that the through-focus image of the cross-striated particle changed to a fishbone-like image with a little under-focusing, which had been considered to be a transitional state during the sheath contraction of phage G. In the optical diffraction pattern of the defocused image, a strong meridional reflection corresponding to the distance of cross-striations in the through-focus image almost disappeared, supporting the change to the fishbone-like image on defocusing.

Bacteriocins↗
PubMed1977

Epidemiological information from active and passive pyocine typing of Pseudomonas aeruginosa.

An investigation was carried out to determine the value of active and passive pyocine typing in the study of Pseudomonas aeruginosa infections acquired in hospital. Active typing was a more reliable and reproducible method than passive typing. Both methods were used in studies of nine outbreaks of infection. In six of these episodes there was good agreement between the two methods. Less clear-cut results were achieved in the remaining three episodes. In one of these, active typing gave more valuable information. However, both methods are easy, convenient and of value in epidemiological studies.

Bacteriocins↗
PubMed1984

Identification of an envelope mutation (env-10) resulting in increased antibiotic susceptibility and pyocin resistance in a clinical isolate of Neisseria gonorrhoeae.

A mutation (env-10) conferring increased susceptibility to drugs, dyes, and detergents was detected in a clinical isolate of Neisseria gonorrhoeae. In certain strains, env-10 also affected susceptibility to pyocins. This mutation was phenotypically similar to but genotypically distinct from previously described env mutations.

Anti-Bacterial Agents↗
PubMed1982

Pyocin-resistant lipopolysaccharide mutans of Neisseria gonorrhoeae: alterations in sensitivity to normal human serum and polymyxin B.

Pyocins from Pseudomonas aeruginosa were used to select several lipopolysaccharide (LPS) mutants of Neisseria gonorrhoeae strain FA19. Three classes of LPS mutans were found in the initial group selected for study. The LPS of one class lacked galactose. That of a second group lacked the typical heptose found in the parental LPS, was reduced in glucose, galactose, and N-acetylglucosamine content, appeared to contain a new unidentified sugar component, and consisted of two species of LPS separable on sodium dodecyl sulfate-polyacrylamide gels. The LPS of a third strain lacked the heptose, glucose, galactose, and N-acetylglucosamine found in the oligosaccharide portion of parental FA19 LPS. The minimal inhibitory concentration for polymyxin B of the mutant strains was 3 to 4 times that of the parental strain. The strains lacking only galactose were as resistant as the parent to the bactericidal action of normal human serum, but cells of the other two classes were quickly killed by serum. Gonococcal LPS thus appears to be important in determining phenotypic properties of the cells.

Blood Bactericidal Activity↗
PubMed1986

Neisseria gonorrhoeae survive intraleukocytic oxygen-independent antimicrobial capacities of anaerobic and aerobic granulocytes in the presence of pyocin lethal for extracellular gonococci.

The resistance of a piliated, transparent variant of Neisseria gonorrhoeae FA19 to intraleukocytic killing by human polymorphonuclear neutrophils (PMN) was examined. In both aerobic and anaerobic PMN monolayers, approximately 2% of the intracellular gonococci survived for as long as 165 min. Anaerobic PMN were as effective as aerobic PMN in the intracellular killing of gonococci. Hence, O2-independent antimicrobial systems of PMN performed a significant role in the intraleukocytic killing of gonococci were intracellular was supported by the elimination of extracellular bacteria by the addition of pyocin 103 and confirmed by the fluorescent antibody staining of intact gonococci after the PMN were permeabilized to antibody with a Formalin-acetone treatment of PMN monolayers. Our data indicate that while the majority of ingested gonococci are killed by O2-independent antimicrobial systems, a small number (about 2%), survive even when care is taken to eliminate extracellular bacteria.

Aerobiosis↗
PubMed1994

Genetic basis of pyocin resistance in Neisseria gonorrhoeae.

The genetic basis for pyocin resistance in Neisseria gonorrhoeae 1291d, 1291e, and FA5100 was determined by Southern blot and DNA sequence analyses. The genes defective in these strains are present as single copies in the gonococcal chromosome. The mutant regions of 1291d, 1291e, and FA5100 were amplified by the PCR. Sequence analysis of the mutant regions demonstrated that strain 1291d contains a 12-bp deletion that results in the loss of four amino acids in phosphoglucomutase, while strain 1291e contains a point mutation that results in the change of an uncharged glycine residue to a charged glutamic acid residue in the same protein. FA5100 contains a nonsense mutation in the gene encoding heptosyltransferase II. The gene previously described as lsi-1 was shown to complement an rfaF mutation in Salmonella typhimurium and has been renamed rfaF.

Amino Acid Sequence↗
PubMed1982

Specific cleavage at fibers of a bacteriophage-tail-like bacteriocin, pyocin R1, by successive treatment with organomercurial compounds and trypsin.

When pretreated with the organomercurial compound that reversibly blocks the adhesion of pyocin R1 to sensitive cells, this bacteriocin became susceptible to trypsin. Trypsinization resulted in the exclusive fragmentation of subunit protein no. 2 among 20 different subunit components and the disappearance of distal knobs from the fibers as well as in irreversible inactivation.

Bacteriocins↗
PubMed1987

Characterization by pyocine typing and serotyping of oral and sputum strains of Pseudomonas aeruginosa isolated from cystic fibrosis patients.

Oral and sputum isolates of Pseudomonas aeruginosa in patients with cystic fibrosis were investigated. Of the 17 patients studied, 12 patients (71%) yielded both mucoid and nonmucoid variants of Pseudomonas aeruginosa from sputum and (or) various oral ecological sites, such as buccal mucosa, tongue dorsum, dental plaques, and saliva. A total of 51 strains of mucoid and nonmucoid Pseudomonas aeruginosa were isolated from these patients and were phenotypically characterized by both pyocine typing and serotyping. Five patients (42%) were colonized or infected by a single strain of Pseudomonas aeruginosa, whereas 7 patients (58%) were cocolonized or coinfected by two or more phenotypically different strains of Pseudomonas aeruginosa. To understand the mechanisms involved in Pseudomonas aeruginosa colonization, it may be necessary to identify multiple isolates of Pseudomonas aeruginosa not only from the sputum but also from the various oral ecological sites and to further explore the role of the oral cavity in this colonization.

Adolescent↗
PubMedDate not supplied

[Serotyping and pyocin typing of Pseudomonas aeruginosa in a study of intrahospital infections].

Typing of Pseudomonas aeruginosa strains is the necessary precondition for the study and control of intrahospital infection caused by this microorganism. Since O-serotype is considered to be the basic epidemiological marker we have studied presence and distribution of some O-serotypes of 235 Pseudomonas aeruginosa strains isolated from 131 patients. The following O-serotypes have been most frequently found: O11 (21%), O6 (18%) and O12 (16%). The combination of sero and pyocin typing proved the presence of epidemic strains at departments of burns and orthopedics.

Bacterial Typing Techniques↗
PubMedDate not supplied

[Four new pyocine types of "Pseudomonas aeruginosa": epidemiological significance (author's transl)].

The pyocin-typing of 448 Ps. aeruginosa from several Hospitals in Lisbonne has been done with the Gillies and Govan method; 69% Portuguese strains are in pyocinotypes n degrees 1, 3, 5 and 7; 16 % are in 24 other pyocinotypes. Four new pyocinotypes were found in a group of 34 atypical strains. The relationship between serotype and pyocinotype was investigated and the most frequent serotypes in Portugal (0:11; 0:6; 0:3) has been subdivided into numerous pyocinotypes with epidemiological significance.

Bacteriocins↗
PubMed1978

[Modified procedure for pyocin typing of Pseudomonas aeruginosa (author's transl)].

The Procedure for pyocin typing of Pseudomonas aeruginosa isolations as proposed by GILLIES and GOVAN has been modified in the following aspects: strains are arranged in a symmetrical way, with a central producer zone and radial indicator streaks, optimal size of inocula for both producer (300 x 10(6)/ml) and indicators (50 X 10(6)/ml) was determined, unsupplemented Tryptic Soy Agar is used giving identical results to those when TSA is supplemented with 5% horse blood. The typing results obtained with this simplified and standardized procedure were identical with those from the cross streak method.

Bacteriocins↗
PubMed1973

Typing of Pseudomonas aeruginosa: comparison of the phage procedure with the pyocine technique.

Two hundred and sixty strains of Pseudomonas aeruginosa were isolated from patients of the Asaf Harofe Government Hospital. The strains were typed by phage technique and 64 of them were also typed according to pyocine sensitivity. The two methods proved complementary, and reduced the number of untypable strains. Phage typing was performed with both routine test dilution (RTD) and more concentrated phage suspensions. The most reliable results were obtained at 100 RTD.

Bacteriocins↗
PubMed1971

Susceptibility of recent isolates of Pseudomonas aeruginosa to gentamicin, polymyxin, and five penicillins, with observations on the pyocin and immunotypes of the strains.

The susceptibilities of recently isolated strains of Pseudomonas aeruginosa to gentamicin, polymyxin B, carbenicillin, ampicillin, penicillin G, and two newer penicillins were tested with the inocula-replicating technique by using undiluted and 10(-3) dilutions of the cultures. With either inoculum, polymyxin B was the most active agent, and a comparison with previous data from this laboratory showed that the susceptibility of P. aeruginosa to this antibiotic had not changed over the past 20 years. Gentamicin was nearly as active as polymyxin, all but 2 of the 141 strains tested with the diluted inoculum being inhibited by 6.25 mug/ml or less. AB-2288, an agent resembling carbenicillin, was four times more active than carbenicillin or BLP-1654; the last two were equally active against the 10(-3) inoculum. A more marked inoculum effect was noted with the penicillin analogues tested, the increase in minimum inhibiting concentration with the undiluted culture being eight-fold for carbenicillin and at least 16-fold for AB-2288 and BLP-1654. Pyocin typing and serotyping failed to demonstrate any clearly predominating types.

Ampicillin↗