Production and Purification of a Staphylococcus epidermidis Bacteriocin

Liquid cultures of Staphylococcus epidermidis 1580 contained rather small amounts of a bacteriocin, staphylococcin 1580, which was found both in the supernatant fluid and in the cell pellet. It could be extracted from the cells with 5% NaCl solution. The staphylococcin production could not be induced by ultraviolet irradiation or treatment with mitomycin C. Bacteria grown on semisolid medium produced a much larger amount of the compound with a high specific activity. The staphylococcin was purified by ammonium sulfate precipitation, ultracentrifugation, and chromatography on Sephadex columns. The purified material was homogeneous on polyacrylamide gel electrophoresis. The molecular weight was between 150,000 and 400,000. The bacteriocin was composed of protein, carbohydrate, and lipid and consisted of subunits exhibiting a molecular weight of about 20,000.     

Characterization of a Staphylococcus aureus Bacteriocin

The bacteriocin produced by a strain of Staphylococcus aureus has been isolated and designated staphylococcin (414), and a study was made of its chemical, physical, and biological properties. The staphylococcin is released in appreciable quantities after breakage of the cells and can be purified through differential centrifugation and column chromatography. In the native state, it appears to be a lipoprotein-carbohydrate complex with a molecular weight in excess of 200,000. The complex can be dissociated by sodium dodecyl sulfate into smaller subunits which retain activity. The gross chemical and physical properties of the bacteriocin closely resemble those ascribed to certain preparations of cell membranes. Staphylococcin (414) is not a lytic enzyme like lysostaphin and does not have the same spectrum of activity. Like other bacteriocins from gram-positive microorganisms, it does not inhibit any gram-negative bacteria, but does inhibit several other genera.     

Some Properties of the Beta-Lactamase Genes in Staphylococcus epidermidis

Eighty-three per cent of 200 different freshly isolated cultures of Staphylococcus epidermidis produced beta lactamase. Growth in the presence of acridine orange or ethidium bromide or growth at 44 C resulted in a high frequency of loss of the beta lactamase genes in some strains of S. epidermidis. The relationship between beta-lactamase production and resistance to mercuric, cadmium and arsenate ions differed from that observed in Staphylococcus aureus. It is postulated that the genes for beta lactamase in certain strains of S. epidermidis are on a plasmid.     

Staphylococcus epidermidis infections

The opportunistic human pathogen Staphylococcus epidermidis has become the most important cause of nosocomial infections in recent years. Its pathogenicity is mainly due to the ability to form biofilms on indwelling medical devices. In a biofilm, S. epidermidis is protected against attacks from the immune system and against antibiotic treatment, making S. epidermidis infections difficult to eradicate.     

Adhesion of Staphylococcus epidermidis and Staphylococcus saprophyticus to a hydrophobic biomaterial

The relative surface charge and hydrophobicity of 16 strains of Staphylococcus epidermidis showed large variations. For this species no relationship between the two surface parameters was found. A highly negative surface charge was observed in all seven encapsulated strains (one S. epidermidis and six Staphylococcus saprophyticus strains). The adhesion of the staphylococci to fluorinated polyethylene-propylene films was not related to the relative surface charge and the hydrophobicity of the bacteria. On films pre-exposed to human plasma, the bacterial adhesion was substantially reduced. Mechanisms involved in the adhesion of coagulase-negative staphylococci to this biomaterial are discussed.     

Phosphatase-negative Staphylococcus epidermidis

As a result of the study of a number of additional characteristics, more than a half of the cultures, formerly identified as phosphatase-negative S. epidermidis according to the scheme of the International Subcommittee on the Taxonomy of Staphylococci and Micrococci, have been shown to be more similar to S. Hominis and S. captis on account of their properties. The study of correlation between the main differentiating characteristics of S. epidermidis has shown that it is poorly pronounced. For this reason the decision to classify a phosphatase-negative culture with S. epidermidis should be based on the study of additional characteristics which differentiate this species not only from S. saprophyticus, but also from other phosphatase-negative staphylococci.     

Partial Purification and Properties of the Pyruvate-Uridine Diphospho-N-Acetylglucosamine Transferase from Staphylococcus epidermidis

A method for the partial purification of the pyruvate-uridine-diphospho-N-acetylglucosamine transferase from Staphylococcus epidermidis is presented. Some properties of the enzyme are discussed.     

Formation and Properties of Persister Cells of Staphylococcus capitis and Staphylococcus epidermidis,Bacteria Inhabiting Human Skin

Microbiology - Persisters (P) are the cells surviving, but not reproducing in the presence of lethal doses of antibiotics (AB). These are the cells of a scarce (0.001–1.0%) subpopulation,...     

Deoxyribonuclease-Positive Staphylococcus epidermidis Strains

Use of the agar plate test for the enzyme deoxyribonucleate 3′-nucleotidohydrolase (deoxyribonuclease) can result in frequent misdiagnosis of Staphylococcus epidermidis as S. aureus.     

Partial Purification and Some Properties of the Uridine Diphospho-N-Acetylglucosamine-Enolpyruvate Reductase from Staphylococcus epidermidis

A method for the partial purification of the uridine diphospho-N-acetylglucosamine-enolpyruvate reductase from Staphylococcus epidermidis is presented. Some properties of the enzyme, including its dependence on monovalent cation and flavine adenine dinucleotide, are discussed.     

Identification of a novel antigen from Staphylococcus epidermidis

A genomic DNA library of Staphylococcus epidermidis NCTC 11047 was constructed, using the Lambda Zap Express cloning vector, and screened with serum collected from a patient with S. epidermidis endocarditis. Sequence analysis of a 30 kDa cloned protein, termed staphylococcal secretory antigen, SsaA, identified a novel protein not previously reported in S. epidermidis. SsaA showed strong homology with two other staphylococcal proteins: SceB from Staphylococcus carnosus and a staphyloxanthin biosynthesis protein from Staphylococcus aureus. Further investigation revealed SsaA to be a highly antigenic protein that was expressed in vivo and could be recovered from whole cells and from the culture supernatant. A combination of Western blot analysis and PCR screening identified SsaA or a homologue in 103/103 staphylococcal strains. SsaA-like genes were not detected in other Gram-positive bacteria of medical importance or a number of Gram-negative organisms. Elevated anti-SsaA IgG antibody levels were detected in sera of five patients with S. epidermidis endocarditis but not in patients with other S. epidermidis infections, endocarditis of other aetiologies or patients with no evidence of infection. The expression of SsaA during episodes of S. epidermidis endocarditis suggests a virulence role specific to the pathogenesis of this infectious disease.     

Properties and Characteristics of a Bacteriocin from Serratia marcescens

A strain of Serratia marcescens was found to produce a bacteriocin that inhibits the growth of certain Escherichia coli strains. This inhibition was bacteriocidal rather than bacteriostatic and was not caused by a bacteriophage. Whereas the bacteriocin was inactive on the 7 Serratia strains tested, it killed 11 of the 20 E. coli strains tested for sensitivity. A relationship of the bacteriocin to a possible colicin cannot as yet be excluded, although E. coli mutants resistant to 1 or 2 of 15 different colicins remained sensitive to the bacteriocin. The bacteriocidal effect by the bacteriocin could be interrupted in a substantial fraction of the treated cell population by the addition of trypsin. The synthesis of the bacteriocin was inducible by ultraviolet light or by starvation for thymidine. Both procedures led to a similar increase in maximum bacteriocin titer relative to noninduced cultures.     

Isolation of Staphylococcus epidermidis from Tobacco

Staphylococcus epidermidis has been isolated in significant numbers from growing tobacco leaves. The organism is also present on cured and aged tobacco.     

Mouse Virulent Strain of Staphylococcus epidermidis

Using 10⁹ or 10⁷ colony-forming units of a strain of Staphylococcus epidermidis (strain 1142) in saline or 5% mucin, respectively, 90 to 100% of mice died within 24 to 48 hr after intraperitoneal challenge infection. These organisms gradually multiplied in the peritoneal cavity when injected intraperitoneally into mice, while the mouse avirulent strain (strain 1124) rapidly decreased and no organisms were found there 20 hr after injection. This strain was capable of inducing resistance against challenge with homologous strains. The resistance appeared as early as the first week and disappeared the 4th week after the immunization. However, no resistance was induced with strain 1124 against challenge with strain 1142. Also, hyperimmune rabbit serum prepared with strain 1142 passively protected against challenge with homologous strain in mice. The protective antibody was absorbed out with homologous organisms but not with strain 1124. Subsequently, a surface substance was obtained from strains 1142 or 1124 by the method of Morse. The 1142 surface substance was capable of inducing a resistance against challenge with the homologous strain but not with the 1124 surface substance. Also, this substance absorbed the protective antibody in hyperimmune rabbit serum prepared with the homologous strain but not with the 1124 surface substance nor with the Smith surface antigen extracted from the Smith strain of Staphylococcus aureus. Conversely, the protective antibody in rabbit anti-Smith strain serum against challenge with the homologous strain was absorbed with the Smith surface antigen but not with the 1142 surface substance. In the agar diffusion test, the 1142 surface substance and the Smith surface antigen produced single precipitin lines only against homologous antisera. Biochemical analysis of the 1142 surface substance showed that the substance contained neither nucleic acids nor proteins but is composed of hexosamine, glycerol, phosphorus, alanine, glycine and phenylalanine.