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PubMed1996

[A case report of active aortic prosthetic valve endocarditis due to methicillin-resistant Staphylococcus epidermidis].

A 71-year-old woman with active aortic prosthetic endocarditis due to Methicillin-resistant Staphylococcus epidermidis (MRSE) and subannular mycotic aneurysm and paravalvular leakage and acute mitral regurgitation underwent emergent surgical treatment. The mycotic aneurysm was closed using a prosthetic patch after surgical debridement. Re-aortic valve replacement with a 21-mm Hancock II prosthesis was performed at the paraannular position by utilizing the patch. Mitral valve was also replaced with a 27-mm Hancock II prosthesis. Antibiotic therapy was provided by vancomycin combined with rifampicin and gentamicin. The following regimen was given, vancomycin 1 g i.v. q12h for 6 weeks plus gentamicin 80 mg/day i.v. for 4 weeks plus rifampicin 450 mg/day orally for 6 weeks. Vancomycin and gentamicin doses were modified appropriately according to the monitored serum levels in the patient with renal failure. Postoperative course was uneventful. The patient is doing well 11 months after surgery and no recurrence of infection has been seen. We conclude that prompt surgical removal of the infected sources and appropriate antibiotic therapy based on the bacteriology may be the only curative treatment for uncontrolled infection at the active phase of MRSE prosthetic endocarditis.

Aged↗
PubMed1990

Adherence of Staphylococcus epidermidis to fibrin-platelet clots in vitro mediated by lipoteichoic acid.

The adherence of two strains of Staphylococcus epidermidis to human fibrin-platelet clots in vitro was investigated. Both strains were noncapsulated, nonhemagglutinating, and nonslime producers. Binding was not related to surface charge, carbohydrate profile, or hydrophobicity of the bacteria. Adherence was reduced four- to sixfold (P less than 0.001) on pretreatment of bacteria with lipase, while neuraminidase, trypsin, phospholipase C, and sodium periodate did not alter their binding. Pretreatment of bacteria with substances known to bind lipoteichoic acid (LTA), such as human albumin and anti-LTA antibodies, also resulted in a fourfold (P less than 0.001) reduction in adherence. Prior incubation of clots with free LTA, but not with deacylated LTA, produced a fourfold (P less than 0.001) decrease in the adherence of homologous and heterologous strains of S. epidermidis. A similar reduction was also observed when LTAs derived from Staphylococcus aureus and Streptococcus pyogenes were used. These data provide evidence that the lipid moiety of LTA has a central role in the adherence of S. epidermidis to fibrin-platelet clots in vitro.

Bacterial Adhesion↗
PubMed2001

Lack of fbe, the gene for a fibrinogen-binding protein from Staphylococcus epidermidis, reduces its adherence to fibrinogen coated surfaces.

The significance of Fbe, a fibrinogen-binding protein in Staphylococcus epidermidis, was investigated. A fbe mutant was constructed by allelic replacement, where a Gentamicin resistance gene replaced a portion of the A region of fbe. Adherence assay to immobilized fibrinogen on polyethylene surfaces and peripheral venous catheters from patients showed that the fibrinogen binding ability of the mutant was reduced compared to its parental strain. This shows that Fbe is a major factor involved in adherence of S. epidermidis to fibrinogen. No difference was found between the wild-type and mutant in their affinity to immobilized fibronectin.

Alleles↗
PubMed2006

Depression of biofilm formation and antibiotic resistance by sarA disruption in Staphylococcus epidermidis.

AIM: To study the effects of disruption of sarA gene on biofilm formation and antibiotic resistance of Staphylococcus epidermidis (S. epidermidis). METHODS: In order to disrupt sarA gene, the double-crossover homologous recombination was applied in S. epidermidis RP62A, and tetracycline resistance gene (tet) was used as the selective marker which was amplified by PCR from the pBR322 and inserted into the locus between sarA upstream and downstream, resulting in pBT2delta sarA. By electroporation, the plasmid pBT2delta sarA was transformed into S. epidermidis. Gene transcription was detected by real-time reverse transcription-PCR (RT-PCR). Determination of biofilm was performed in 96-well flat-bottomed culture plates, and antibiotic resistance was analyzed with test tube culture by spectrophotometry at 570 nm respectively. RESULTS: A sarA disrupted strain named S. epidermidis RP62Adelta sarA was constructed, which was completely defective in biofilm formation, while the sarA complement strain RP62Adelta sarA (pHPS9sarA) restored the biofilm formation phenotype. Additionally, the knockout of sarA resulted in decreased erythromycin and kanamycin resistance of S. epidermidis RP62A. Compared to the original strain, S. epidermidis RP62Adelta sarA had an increase of the sensitivity to erythromycin at 200-400 microg/mL and kanamycin at 200-800 microg/mL respectively. CONCLUSION: The knockout of sarA can result in the defect in biofilm formation and the decreased erythromycin and kanamycin resistance in S. epidermidis RP62A.

Bacterial Proteins↗
PubMed1996

Detection and measurement of Staphylococcus epidermidis slime using an ELISA technique.

A polyclonal rabbit anti-serum against the strong slime-producing Staphylococcus epidermidis strain RP62A was absorbed with the slime-negative phase variant of this strain PV1 in order to remove not slime-specific antibodies. Using this antiserum we established an ELISA which enables detection of slime production in S. epidermidis extracts. The ELISA showed high absorbance when extracts from slime-positive strains (confirmed in the tissue culture tube test) were used as antigens. The high absorbance of slime-positive strains was greatly reduced by periodate oxidation of the extracts and was resistant to proteinase digestion suggesting that the detected antigen is composed of polysaccharides. In contrast to other rapid and simple laboratory detection methods for S. epidermidis slime, the slime-specific ELISA gave positive results in the presence of human serum.

Animals↗
PubMed1976

Susceptibility of Staphylococcus aureus and Staphylococcus epidermidis to 65 antibiotics.

The susceptibilities of 36 recent isolates of Staphylococcus aureus and 35 recent isolates of Staphylococcus epidermidis were determined against each of 65 antimicrobial agents and against two of them in combination. Rifampin was the most active of all the agents tested against both S. aureus and S. epidermidis. Among the penicillins, cloxacillin, dicloxacillin, and nafcillin were most active, although benzylpenicillin and phenoxymethyl penicillin were more active against susceptible strains. Cephaloridine was the most active of the cephalosporins, and sisomicin was the most active aminoglycoside. Minocycline was more active than the other tetracycline analogues tested. Among the macrolide-lincomycin compounds in clinical use, clindamycin was more active, and lincomycin was less active than erythromycin. The synergy of trimethoprim-sulfamethoxazole was more striking against S. aureus than against S. epidermidis. The median minimal inhibitory concentrations of the penicillins, cephalosporins, and aminoglycosides were lower against S. aureus, whereas the minimal inhibitory concentrations of the tetracyclines were lower against S. epidermidis.

Anti-Bacterial Agents↗
PubMed2002

Influence of Tn917 insertion on transcription of the icaADBC operon in six biofilm-negative transposon mutants of Staphylococcus epidermidis.

Insertion of Tn917 into the icaADBC operon determines a biofilm-negative phenotype in biofilm-producing Staphylococcus epidermidis due to the inactivation of the genes responsible for the synthesis of the polysaccharide intercellular adhesin. We previously characterized six isogenic biofilm-negative transposon mutants of S. epidermidis 1457 with Tn917 insertions in either icaA or icaC. Northern blot analysis using ica- and Tn917-specific probes revealed that ica sequences located upstream and downstream of the transposon insertion site were still transcribed in five mutants in which Tn917 was inserted in the same transcriptional orientation. Outward-directed transcription initiating from within the transposon resulted in the complete expression of individual ica genes. Our results indicate that not only the inactivation of the entire operon but the isolated interruption of individual icaA and icaC genes led to a biofilm-negative phenotype in S. epidermidis. Tn917 mutagenesis may also result in the activation of genes located downstream of the insertion site.

Amino Acid Sequence↗
PubMed2000

Identification of a second lipase gene, gehD, in Staphylococcus epidermidis: comparison of sequence with those of other staphylococcal lipases.

The identification and molecular characterization of a previously unidentified lipase, gehD, from the human cutaneous commensal Staphylococcus epidermidis is reported. A lipase-GehC-deficient but otherwise isogenic mutant of S. epidermidis 9 was constructed by allele replacement. However, the mutant was found to retain 50% of the wild-type lipase activity in liquid culture. Rescreening of a genomic library revealed the presence of a second lipase gene, gehD, which was subsequently mapped and sequenced. In common with other staphylococcal lipases, GehD appeared to be translated as a 650-700 amino acid precursor which is processed post-translationally to an extracellular mature lipase of 360 amino acids with a size of approximately 45 kDa. Comparison of the amino acid sequence of GehD with those of other staphylococcal lipases revealed a high level of conservation between the mature lipase domains of different species. By hybridization studies, both gehC and gehD genes were found to be present in S. epidermidis isolates from both clinical and non-clinical backgrounds, but neither hybridized to DNA isolated from other staphylococcal strains. Construction of a phylogenetic tree and calculation of amino acid sequence homologies between mature lipases, however, suggested that the lipases of S. epidermidis may be more closely related to those of Staphylococcus aureus than to each other.

Amino Acid Sequence↗
PubMed2005

Persistence of resistant Staphylococcus epidermidis after single course of clarithromycin.

We examined how a common therapy that includes clarithromycin affects normally colonizing Staphylococcus epidermidis. Samples from the nostrils of 5 patients receiving therapy were collected before, immediately after, 1 year after, and 4 years after treatment. From each patient and sample, S. epidermidis strains were isolated and analyzed for clarithromycin susceptibility and presence of the erm(C) gene. We show that macrolide-resistant strains of S. epidermidis were selected during therapy and that the same resistant strain may persist for 4 years, in the absence of further antimicrobial treatment.

Anti-Bacterial Agents↗
PubMed1997

Enzyme-linked lectinsorbent assay measures N-acetyl-D-glucosamine in matrix of biofilm produced by Staphylococcus epidermidis.

An enzyme-linked lectinsorbent assay (ELLA) was developed for quantification of in situ biofilm produced by Staphylococcus epidermidis in polystyrene 96-well tissue culture plates with phosphatase-labeled wheat germ agglutinin (WGA) as a specific probe for the GlcNAcbeta-1,4n component of exocellular matrix material (EMM) that is responsible for intercellular adhesion and accumulation. The ELLA and the modified Christensen dye assay were used to test 13 laboratory strains of coagulase-negative staphylococci and 10 clinical isolates of S. epidermidis. Four biofilm-positive laboratory strains of S. epidermidis were positive by both tests, and six biofilm-negative strains were negative by both. One strain of S. hemolyticus was positive by the ELLA only. Two of the 10 clinical isolates of S. epidermidis were positive by both assays, two were negative by both, and the remaining were positive by the ELLA only. The ELLA was objective, reproducible, specific, sensitive, and useful for screening strains for their capacity to adhere to plastic, produce EMM, and form biofilm.

Acetylglucosamine↗
PubMed2000

Biomaterial-associated persistence of Staphylococcus epidermidis in pericatheter macrophages.

Biomaterial surfaces may be modified to reduce bacterial adhesion. The susceptibility in mice to Staphylococcus epidermidis infection in tissue surrounding the commonly used catheter materials-silicon elastomer (SE), polyamide (PA), and their surface-modified polyvinylpyrrolidone (PVP)-grafted derivatives, SE-PVP and PA-PVP, respectively-was assessed. Abscesses developed around SE-PVP. Around SE, PA, and PA-PVP catheters, no signs of infection were observed, although mice carrying PA-PVP developed septicemia after 14-21 days. S. epidermidis was cultured from the tissue surrounding PA-PVP segments. Cells around PA-PVP segments containing large numbers of bacteria were identified as macrophages by use of immunohistochemistry and electron microscopy. This persistence of intracellular bacteria was also observed around SE-PVP, SE, and PA catheters, although to a lesser extent. The cytokine profiles around the 4 materials were different. Implanted biomaterial induces an inflammatory response favorable to the persistence of S. epidermidis. Intracellular persistence of bacteria inside macrophages may be a pivotal process in the pathogenesis of biomaterial-associated infection.

Animals↗
PubMed2002

Differential expression of methicillin resistance by different biofilm-negative Staphylococcus epidermidis transposon mutant classes.

Biofilm formation mediated by polysaccharide intercellular adhesin (PIA) is the major virulence factor of Staphylococcus epidermidis and is often associated with methicillin resistance. Transposon Tn917 insertions leading to a biofilm-negative phenotype in the biofilm-producing S. epidermidis strain 1457 (mecA-negative) were transferred into the methicillin-resistant, biofilm-producing S. epidermidis 1057 (mecA-positive) by transduction. According to their phenotypes and genotypes, the mutants could be separated into genetic classes I to IV (D. Mack, H. Rohde, S. Dobinsky, J. Riedewald, M. Nedelmann, J. K. M. Knobloch, H.-A. Elsner, and H. H. Feucht, Infect. Immun. 68:3799-3807, 2000). All transductants of S. epidermidis 1057 had phenotypes for biofilm formation similar to those of the corresponding mutants of S. epidermidis 1457. With a mecA-specific probe, identical hybridization patterns were observed for wild-type S. epidermidis 1057 and all the transductants. There were minor changes in oxacillin MICs for Class II and III transductants compared to those for wild-type S. epidermidis 1057. On population analysis, S. epidermidis 1057 displayed a heterogeneous expression type of resistance with an oxacillin MIC of > or =6 microg/ml for more than 90% of the cells. An almost identical profile was observed with biofilm-negative class I mutants, where the transposon insertions inactivate the icaADBC gene locus essential for PIA synthesis. In contrast, class III mutants were more sensitive to oxacillin with a MIC of < or =1 microg/ml for more than 90% of the cells. The class IV mutant displayed homogeneous resistance with a MIC of > or =50 microg/ml for more than 90% of the cells. On oxacillin gradient plates, the class II mutant displayed decreased resistance. Apparently, different independent mutations leading to a biofilm-negative phenotype of S. epidermidis by influencing expression of icaADBC on the level of transcription significantly influence the expression of methicillin resistance. However, transcription of mecA was not significantly altered in the different transductants compared to the wild type, independent of mecA induction with oxacillin, indicating that other mechanisms influencing phenotypic expression of methicillin resistance are involved.

Bacterial Proteins↗
PubMed1995

Effect of iron limitation on the amount of slime produced by strains of Staphylococcus epidermidis.

To investigate the effect of iron limitation on the amount of slime production by most strains of Staphylococcus epidermidis, ethylenediamine-di-o-hydroxyphenol acetic acid (EDDA), was added to the growth medium and twenty clinically relevant strains were assayed for slime production during growth in standard tryptic soy broth (TSB) and iron-limited TSB. Findings revealed that the density of the biofilm which formed on the base of microtitre plates was dependent on the degree of iron limitation, characteristics of the test strains and the stage of the growth cycle.

Biofilms↗
PubMed1991

Natural history of chronic Staphylococcus epidermidis foreign body infection in a mouse model.

The development and characterization of a mouse model of chronic Staphylococcus epidermidis foreign body infection was done with two clinical isolates that differed in degree of extracellular slime production. Segments of Silastic catheters bearing preformed S. epidermidis biofilms were implanted intraperitoneally, and mice were assessed after 3 and 6 months. Both test strains of S. epidermidis persisted at the implant site through the 6-month follow-up in 80% of the mice, regardless of the degree of slime production. There was no evidence of overt animal morbidity, and microbiologic assessment of other peritoneal sites did not reveal dissemination of bacteria from the infected focus. In comparison with control mice, animals harboring chronic foreign body infection presented marked peripheral neutrophilia and mild anemia.

Animals↗
PubMed2005

Rapid diffusion of fluorescent tracers into Staphylococcus epidermidis biofilms visualized by time lapse microscopy.

The transient diffusion of fluorescent tracers into biofilm cell clusters of Staphylococcus epidermidis was visualized by time lapse confocal scanning laser microscopy. Rhodamine B diffused into the center of cell clusters that were 200 to 600 microm in diameter within a few minutes. The apparent effective diffusion coefficient calculated from these data averaged 3.7 x 10(-7) cm(2) s(-1) or 11% of the value in pure water. Fluorescein diffused into biofilm more rapidly, with a diffusion coefficient that averaged 1.6 x 10(-6) cm(2) s(-1), or 32% of the value in water. This study provides direct, visual confirmation that solutes the size of many antibiotics and biocides can diffuse rapidly into biofilms.

Biofilms↗
PubMedDate not supplied

In vitro antibacterial activity of TOC-50, a new parenteral cephalosporin against methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis.

The in vitro activity of TOC-50, a new parenteral cephalosporin, was assessed against methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus epidermidis (MRSE). TOC-50 showed excellent activity, which was stronger than that of methicillin, cloxacillin, the cephalosporins tested, imipenem, gentamycin, minocycline, ofloxacin and ciprofloxacin against MRSA and had a minimum inhibitory concentration (MIC) comparable to that of vancomycin (the MICs of TOC-50 and vancomycin for growth inhibition of 90% of the strains tested were 3.13 and 1.56 micrograms/ml, respectively). Against MRSE, TOC-50 exhibited excellent activity, which was stronger than that of methicillin, ampicillin, the cephalosporins tested and imipenem, and was twice as active as vancomycin. In terms of the bactericidal effect against MRSA, TOC-50 was superior to vancomycin.

Anti-Bacterial Agents↗
PubMed1980

Identity and interspecific transfer of gentamicin-resistance plasmids in Staphylococcus aureus and Staphylococcus epidermidis.

The hypothesis that emergence of gentamicin-resistant strains of Staphylococcus aureus and Staphylococcus epidermidis in a neonatal special care nursery was the result of transfer of a single plasmid between these two species was examined. In experiments with mixtures of staphylococci, either in mixed cultures or on human skin, isolates of S. aureus and S. epidermidis transferred their gentamicin-resistance plasmids both intra- and interspecifically. By electron microscopy, the molecular masses of the plasmids from S. aureus and S. epidermidis were the same, 12.2 +/- 0.36 (standard deviation) and 12.3 +/- 0.56 megadaltons, respectively. Restriction endonuclease analysis of the plasmids from five isolates of S. aureus and two isolates of S. epidermidis, with use of the enzymes HaeIII, EcoRI, XbaI, and HindIII, showed no differences in the digestion patterns of the seven gentamicin-resistance plasmids. The results supported the hypothesis that plasmid transfer between S. aureus and S. epidermidis occurs in nature.

Conjugation, Genetic↗