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PubMed2006

Expression of TNF-alpha, IL-1beta, and IFN-gamma in Staphylococcus epidermidis slime-positive experimental endophthalmitis is closely related to clinical inflammatory scores.

PURPOSE: The purpose of this study was to investigate the expression of inflammatory cytokines TNF-alpha, IL-1beta, and IFN-gamma in the vitreous after experimentally induced endophthalmitis by a Staphylococcus epidermidis slime-producing strain. METHODS: Seventy-two experimental Lewis rats received an intravitreal injection of 7000 viable organisms of Staphylococcus epidermidis slime-producing ATCC strain 35983, while 72 control rats received an intravitreal injection of sterile normal saline. Eyes were graded daily for signs of clinical inflammation and were removed 6, 12, 24, 48, 72 h, and 7 days after injection. Vitreous was obtained and titers of TNF-alpha, IL-1beta, and IFN-gamma were measured with established enzyme-linked immunosorbent assays. RESULTS: In the experimental group, the clinical inflammatory score reached maximum (4+) within 24 h, while inflammation was almost abolished by day 7 (score 0-0.5+). Statistically increased levels of TNF-alpha and IL-1beta were detected in the experimental vitreous with maximum levels observed at 12 h. IFN-gamma was also detected in the experimental vitreous and reached maximum levels at 48 h. None of the cytokines examined was detected in sera at any time point in experimental or control rats. CONCLUSIONS: The results of this study suggest that Staphylococcus epidermidis experimental endophthalmitis induces the expression of cytokines TNF-alpha, IL-1beta, and IFN-gamma in the vitreous. The time course of those cytokine expression levels is closely associated to the clinical presentation of this endophthalmitis model.

Animals↗

PubMed1998

Adhesion of Staphylococcus epidermidis and transposon mutant strains to hydrophobic polyethylene.

Staphylococcus epidermidis capsular polysaccharide adhesin (PS/A) and slime were studied as possible mediators of bacterial adhesion to NHLBI polyethylene (PE) under dynamic flow. This putative interaction was examined by quantifying the adhesion of M187 (PS/A+, slime+) parent strain and isogenic transposon mutant strain sn3 (PS/A-, slime-) to polyethylene (PE) under a range of physiologic shear stress conditions in both phosphate-buffered saline (PBS) and 1% platelet poor plasma (PPP). No significant differences in adhesion were noted between the M187 and sn3 strains in either test medium. However, adhesion of both strains in 1% PPP was decreased 75-95% compared to adhesion in PBS. In PBS, adhesion was shear stress dependent from 0-15 dyne/cm2, after which adhesion was comparatively shear stress independent. Adhesion in 1% PPP was independent of shear stress. Epifluorescent imaging of both strains labeled for slime confirmed the presence of slime on the surface of M187 and suggested that PS/A and slime promote the formation of large aggregates, as aggregates were totally absent in the images of the sn3 strain. The results suggest that PS/A and slime do not mediate S. epidermidis adhesion to bare PE or PE with adsorbed plasma proteins, but may be necessary for intercellular adhesion, which is important for biofilm formation.

Bacterial Adhesion↗

PubMed1986

Opsonic requirements of Staphylococcus epidermidis.

The opsonic requirements of 18 strains of Staphylococcus epidermidis were compared in pooled normal human serum and in peritoneal dialysate from patients undergoing continuous ambulatory peritoneal dialysis (CAPD). A serum concentration of 2.5% gave optimal opsonisation. The opsonisation of all strains was antibody- and complement-dependent, and there were no significant differences in the pattern of their opsonic requirements. Peritoneal-dialysis effluent from uninfected patients was a poor source of opsonins because of the low levels of immunoglobulin G and of the C3 component of complement it contained. Growth of S. epidermidis in peritoneal-dialysis effluent rather than in broth did not alter its opsonic requirements. Strains from patients undergoing CAPD and suffering from peritonitis were not more resistant to opsonisation and phagocytic killing than those from other sources.

Complement System Proteins↗

PubMed2007

Biofilm formation by Staphylococcus epidermidis on nitrogen ion implanted CoCrMo alloy material.

Staphylococcus epidermidis is the primary cause of medical device-related infections due to its adhesion and biofilm forming abilities on biomaterial surfaces. For this reason development of new materials and surfaces to prevent bacterial adhesion is inevitable. In this study, the adhesion of biofilm forming S. epidermidis strain YT-169a on nitrogen (N) ion implanted as well as on as-polished CoCrMo alloy materials were investigated. A medical grade CoCrMo alloy was ion implanted with 60 keV N ions to a high dose of 1.9 x 10(18) ions/cm(2) at substrate temperatures of 200 and 400 degrees C. The near-surface implanted layer crystal structures, implanted layer thicknesses, and roughnesses were characterized by XRD, SEM and AFM. The number of adherent bacteria on the surfaces of N implanted specimens was found to be 191 x 10(6) CFU/cm(2) for the 200 degrees C and 70 x 10(6) CFU/cm(2) for the 400 degrees C specimens compared to the as-polished specimen (3 x 10(6) CFU/cm(2)). The adhesion test results showed that S. epidermidis strain YT-169a adhere much more efficiently to the N implanted surfaces than to the as-polished CoCrMo alloy surface. This was attributed mainly to the rougher surfaces associated with the N implanted specimens in comparison with the relatively smooth surface of the as-polished specimen.

Bacterial Adhesion↗

PubMed2003

Emergence of a teicoplanin-resistant small colony variant of Staphylococcus epidermidis during vancomycin therapy.

Small colony variants of Staphylococcus aureus can cause persistent and recurrent infections. There are only a few reports of small colony variants of coagulase-negative staphylococci. Herein a case of infection with a teicoplanin-resistant small colony variant of Staphylococcus epidermidis is presented. The small colony variant was isolated from blood cultures of a patient with acute leukaemia and therapy-induced neutropenia who was treated with vancomycin for catheter-associated bloodstream infection. Despite removal of the catheter and adequate antibiotic therapy, the infection did not clear and the patient died 20 days after continuous antibiotic therapy.

Aged↗

PubMed1985

Formation of HCN by human phagocytosing neutrophils--1. Chlorination of Staphylococcus epidermidis as a source of HCN.

Phagocytosis of Staphylococcus epidermidis by human neutrophils is accompanied by HCN liberation. The amount of HCN evolved is significantly higher when the bacteria are damaged by penicillin. One of the substrates yielding HCN during phagocytosis are N-dichloroglycyl residues of bacterial peptidoglycan formed by the chlorinating myeloperoxidase-H2O2-Cl- system of neutrophils. HCN deriving from the bacterial structures constitutes 6-12% of total HCN liberated during phagocytosis, which indicates that there are other substrates for HCN production. Chlorination process within phagocytosing neutrophils seems to be essential for formation of both, total HCN and that deriving from bacterial structures.

Chlorine↗

PubMed1989

The effects of heparin on rifampin activity against Staphylococcus epidermidis biofilms.

Rifampin shows unique antimicrobial activity against Staphylococcus epidermidis biofilms, although in the in vitro situation rifampin resistance emerges rapidly by the selection of preexisting resistant mutants present in a small number in any large bacterial population. Fresh peritoneal dialysis solution is synergistic with rifampin suppressing rifampin resisters. The antimicrobial properties of rifampin are affected by heparin and protamine in entirely different directions. Heparin blocks the action of rifampin whereas protamine is synergistic producing a total bactericidal outcome. Protamine, when combined with heparin, unexpectedly did not influence the ability of heparin to antagonize rifampin. The mechanisms involved are unknown. The results are discussed in terms of known characteristics of the drugs and of the biofilm surface.

Bacterial Adhesion↗

PubMed1996

Selection of subpopulations resistnat to amikacin and netilmicin of gentamicin-resistant clinical strains of Staphylococcus aureus and Staphylococcus epidermidis.

Recently we have found several strains of Staphylococcus aureus and Staphylococcus epidermidis, which in spite of containing aminoglycoside-modifying enzymes (AMEs) remained susceptible to antibiotics such as netilmicin (NET) and amikacin (AN). Assuming an interest in this agent from a clinical point of view, the aim of this study was to determine if these strains became resistant after prolonged contact with such antibiotics. We found that minimal inhibitory concentrations (MICs) of the bacterial strains not only increased when using these two agents, but also when using other aminoglycosides such as gentamicin (GM), tobramycin (TM), amikacin (AN) and isepamicin (ISE). In order to see the effect of prolonged use of NET on enzyme production, three strains containing AMEs were selected and we could observe an increase in the enzyme levels after successive passages through media containing NET.

Amikacin↗

PubMed2003

Serum amyloid A in the serum and milk of ewes with mastitis induced experimentally with Staphylococcus epidermidis.

Mastitis was induced experimentally in ewes with Staphylococcus epidermidis, and the concentrations of serum amyloid A (SAA) in milk and serum, and the somatic cell counts and bacteria in the milk were determined for up to 10 weeks in two experiments, each examining five infected and five control ewes. The somatic cell counts peaked eight hours after infection and preceded an increase in SAA in milk. A maximum concentration of 6460 microg/ml SAA was recorded in milk from the infected sheep, compared with a mean concentration of 1.4 microg/ml in the control sheep. The mean peak concentration of SAA in serum (206.8 microg/ml) occurred earlier (one day after infection) than in milk. The serum concentration of SAA in the healthy animals ranged from 0 to 29.4 microg/ml. There was no correlation between the concentrations of SAA in serum and milk.

Animals↗

PubMed1993

Bacteraemia due to recurrent reinfection with Staphylococcus epidermidis associated with defective opsonisation and procidin function in serum.

AIMS: To differentiate between reinfection and relapsing infection with Staphylococcus epidermidis in a middle-aged woman with defective opsonisation and procidin function in serum. METHODS: Microbiological typing was done by biotyping, phage typing, and polyacrylamide gel electrophoresis of radiolabelled bacterial proteins (radioPAGE method). Polymorphonuclear cell function was assessed in vitro by phagocytosis and killing of Candida albicans; measurement of neutrophil random locomotion and chemotaxis; reduction of nitroblue tetrazolium after stimulation by opsonised Candida and a radiometric saccharomyces opsonisation assay. The effect of plasma infusions on opsonic activity was assessed by chemiluminescence using control polymorphonuclear leucocytes with a laboratory strain of S epidermidis opsonised with either patient or control serum. RESULTS: Recurrent reinfection with different strains of Staphylococcus epidermidis rather than relapsing infection was confirmed as having occurred by typing bacterial strains. The RadioPAGE method detected all the S epidermidis strains involved in this patient's illness. The patient's serum was shown to be defective in both opsonin and procidin function. The defects were correctable in vitro by the addition of normal serum. Clinical recovery occurred after repeated infusions of normal fresh frozen plasma and prolonged antibacterial treatment; antibacterial treatment alone was insufficient. CONCLUSIONS: The radioPAGE method is useful in distinguishing recurrent reinfection with S epidermidis from relapsing infection with this organism. Elucidation of the nature of, and underlying predisposition to, infection in the patient studied allowed a rational treatment plan of plasma infusion combined with antibacterial treatment to be devised which ultimately proved successful.

Autoradiography↗

PubMed1983

Clinical and microbiologic aspects of serious infections caused by Staphylococcus epidermidis.

10 patients with serious infections caused by Staphylococcus epidermidis (8 cases of endocarditis in non-prosthetic valves, 1 was complicated by osteomyelitis, 1 case of osteomyelitis, and 1 case of septicemia) are described. Clinical and microbiologic features were evaluated including antibiotic sensitivity and synergy studies, phage typing and biotyping. Endocarditis tended to affect the elderly population and the clinical manifestations were quite similar to those caused by Streptococcus viridans. Both patients with osteomyelitis had involvement of the cervical spine with excellent response to antibiotic therapy. The only patient with septicemia acquired via hyperalimentation had delayed clearance of the bacteremia but ultimately responded to intravenous antibiotics. Rifampicin was the most effective of all antibiotics tested. All isolates were sensitive to penicillinase-resistant penicillins and cephalosporins and over half were sensitive to penicillin. Full synergistic activity was demonstrated with cephalothin and nafcillin in combination with rifampicin, and rifampicin-vancomycin was partially synergistic against the majority of the strains. Five of 8 available isolates were non-phage typeable and no definite pattern was established for various types of infections. Four of the 8 isolates were classified as biotype SIIa, 2 biotype SIIc and 2 biotype SVh.

Adult↗

PubMed1991

Screening tests for the detection of methicillin resistance in Staphylococcus epidermidis.

Methods to detect resistance to methicillin in Staphylococcus epidermidis were studied in order to find a rapid screening test suitable for routine use. One hundred and forty-nine clinical isolates, 16 isolates from skin of healthy people and two reference strains were studied. Hypersecretion of beta-lactamase as a cause of methicillin resistance was eliminated in the strains studied. Tube and microtitre breakpoint, agar breakpoint and disc diffusion methods were compared. The breakpoint for methicillin resistance used was 16 mg/L in broth and 10 mg/L in agar. The discs used contained 1 and 5 micrograms oxacillin and 5 and 10 micrograms methicillin. Turbidimetric measurements in broth during incubation were carried out using the Bioscreen analysing system. The skin strains were founf to be susceptible in all tests. Using an inoculum of 10(7) cfu/mL 111/149 clinical isolates were classified as resistant after incubation for 24 h at 35 degrees C using the tube and microtitre breakpoint tests, incubation for 72 h did not increase this rate. When an inoculum of 10(5) cfu/mL was used 73% of these strains were identified within 24 h and all within 72 h with the tube breakpoint test. Using the microtitre breakpoint test, with an inoculum of 10(5) cfu/mL or lower, all resistant strains were not detected within 48 h. All agar breakpoint tests required 48 h incubation for reliable results. Only the 1 microgram oxacillin disc always separated strains found to be resistant or susceptible in the tube breakpoint test. The zone of inhibition was clearly readable after 16 h of incubation at 35 degrees C.

Culture Media↗

PubMed1986

The adherence of Staphylococcus aureus, Staphylococcus epidermidis and Escherichia coli on cotton, polyester and their blends.

The adherent behaviour of the Gram-positive Staphylococcus aureus and Staphylococcus epidermidis and the Gram-negative Escherichia coli on cotton, polyester and their blends through contact in aqueous suspensions was studied. Staphylococcus epidermidis was found to adhere to fabrics much more so than Staph. aureus. The adherence of both Staph. epidermidis and Staph. aureus to fabrics increased as the content of polyester fibres in the fabrics increased. The attachment of E. coli to all fabrics was very low and was not affected by the fibre contents. Total numbers of adherent bacteria on cotton and polyester fabrics were related directly to the concentrations of the bacterial suspensions. The extents of adherence, expressed by the percentage of adherent bacteria from the suspension, however, were independent of the concentration. The length of contact with bacteria was also found to affect the adherence of bacteria on fabrics studied.

Absorption↗

PubMed1984

Methicillin-resistant Staphylococcus epidermidis blepharitis.

Blepharoconjunctivitis caused by methicillin-resistant strains of Staphylococcus epidermidis occurred in two hospitalized patients, a 74-year-old man and a 19-year-old man. Both strains were resistant to multiple courses of topical antibiotic therapy. Successful treatment in both cases depended upon antibiotic sensitivity testing. These methicillin-resistant strains of S. epidermidis, like methicillin-resistant strains of Staphylococcus aureus, demonstrated almost complete cross-resistance to cephalosporins despite apparent sensitivity on Kirby-Bauer disk sensitivity testing. Topical vancomycin was curative in one case. In the other case, treatment with topical gentamicin, intravenous cefoperazone, and oral rifampin led to resolution of the symptoms.

Adult↗

PubMed1998

Molecular cloning of a 32-kilodalton lipoprotein component of a novel iron-regulated Staphylococcus epidermidis ABC transporter.

Our previous studies identified two iron-regulated cytoplasmic membrane proteins of 32 and 36 kDa expressed by both Staphylococcus epidermidis and Staphylococcus aureus. In this study we show by Triton X-114 phase partitioning and tritiated palmitic acid labelling that these proteins are lipoproteins which are anchored into the cytoplasmic membrane by their lipid-modified N termini. In common with those of some other gram-positive bacteria, these highly immunogenic lipoproteins were released from the bacterial cell into the culture supernatants, with release being promoted by growth of the bacteria under iron-restricted conditions. Immunoelectron microscopy with a monospecific rabbit antiserum to the 32-kDa S. epidermidis lipoprotein showed that the majority of the antigen was distributed throughout the staphylococcal cell wall. Only minor quantities were detected in the cytoplasmic membrane, and exposure of the lipoprotein on the bacterial surface was minimal. A monoclonal antibody raised to the 32-kDa lipoprotein of S. aureus was used in immunoblotting studies to investigate the conservation of this antigen among a variety of staphylococci. The monoclonal antibody reacted with polypeptides of 32 kDa in S. epidermidis and S. aureus and of 40 kDa in Staphylococcus hominis. No reactivity was detected with Staphylococcus lugdunensis, Staphylococcus cohni, or Staphylococcus haemolyticus. The gene encoding the 32-kDa lipoprotein from S. epidermidis has been isolated from a Lambda Zap II genomic DNA library and found to be a component of an iron-regulated operon encoding a novel ABC-type transporter. The operon contains three genes, designated sitA, -B, and -C, encoding an ATPase, a cytoplasmic membrane protein, and the 32-kDa lipoprotein, respectively. SitC shows significant homology both with a number of bacterial adhesins, including FimA of Streptococcus parasanguis and ScaA of Streptococcus gordonii, and with lipoproteins of a recently described family of ABC transporters with proven or putative metal ion transport functions. Although the solute specificity of this novel transporter has not yet been determined, we speculate that it may be involved in either siderophore- or transferrin-mediated iron uptake in S. epidermidis.

ATP-Binding Cassette Transporters↗

PubMed2001

A Shared noncapsular antigen is responsible for false-positive reactions by Staphylococcus epidermidis in commercial agglutination tests for Staphylococcus aureus.

Many of the commercial slide agglutination tests for Staphylococcus aureus incorporate antibodies against cell surface antigens associated with methicillin resistance, including capsular polysaccharides and an uncharacterized antigen, serotype 18. These tests are more sensitive than the first-generation agglutination procedures that detected only bound coagulase and protein A, but they suffer from false-positive reactions with some coagulase-negative staphylococci. The aim of this study was to elucidate the mechanism for false-positive agglutination by S. epidermidis in these tests. A group of methicillin-resistant S. aureus (MRSA) isolates, including a serotype 18 strain, that were not detectable in the first-generation tests were found to be of capsular polysaccharide type 8. All of these isolates were deficient in bound coagulase and/or protein A, and they possessed a heat-stable, proteinaceous antigen that was absent from a prototype capsule type 8 strain. Enzyme-linked immunosorbent assay and agarose gel immunodiffusion experiments demonstrated that this proteinaceous antigen was also present on both methicillin-sensitive and methicillin-resistant S. epidermidis clinical isolates. S. epidermidis strains that gave false-positive agglutination test results had a considerably higher level of this antigen than strains that gave the correct negative result. These findings reveal the importance of the careful selection of MRSA strains for raising anti-capsular type 8 antibodies for use in agglutination tests. Strains devoid of the antigen shared with S. epidermidis should be used to eliminate potential cross-reactions with this coagulase-negative coccus.

Agglutination Tests↗

PubMed1963

EFFECT OF ANAEROBIC GROWTH ON NITRATE REDUCTION BY STAPHYLOCOCCUS EPIDERMIDIS.

Jacobs, N. J. (American Meat Institute Foundation, Chicago, Ill.), J. Johantges, and R. H. Deibel. Effect of anaerobic growth on nitrate reduction by Staphylococcus epidermidis. J. Bacteriol. 85:782-787. 1963.-In anaerobic cultures, a strain of Staphylococcus epidermidis failed to reduce nitrate, although nitrate was reduced in stationary cultures grown in the presence of air. Resting suspensions of cells grown in air reduced nitrate. Although suspensions of cells grown anaerobically did not reduce nitrate, the nitrate reductase enzyme was shown to be present. When the artificial electron carrier, benzyl viologen, was added to suspensions of cells grown anaerobically, nitrate was reduced, indicating that an electron carrier required for nitrate reduction was missing. The addition of hemin to the growth medium enabled anaerobic cultures to reduce nitrate.

Benzyl Viologen↗

PubMed2005

Detection of icaA and icaD loci by polymerase chain reaction and biofilm formation by Staphylococcus epidermidis isolated from dialysate and needles in a dialysis unit.

Staphylococcus epidermidis, a coagulase-negative staphylococcus, is a major cause of infections associated with indwelling medical devices. Certain strains produce slime and form biofilm on polymer surfaces, where their pathogenicity is associated with biofilm formation. In this report, we investigated the presence or absence of the intercellular adhesion icaA and icaD genes by polymerase chain reaction, and phenotypic biofilm production was examined by qualitative Congo red agar (CRA) assay. A total of 32 strains of S. epidermidis were identified from dialysates and needles 4h after the initiation of dialysis. Qualitative biofilm production revealed that 16 (50%) strains produced slime on CRA plates. Among the 23 strains positive for the ica operon, 15 were biofilm positive on CRA, eight were biofilm negative, and one was icaA and icaD negative but produced slime. These results show that the ability of S. epidermidis to produce slime is not associated with the presence of icaA and icaD genes.

Bacterial Adhesion↗