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PubMed2001

A rapid, non-destructive method for the determination of Staphylococcus epidermidis adhesion to surfaces using quartz crystal resonant sensor technology.

AIMS: To investigate the use of quartz crystal resonant sensor (QCRS) technology to determine the adhesion of Staphylococcus epidermidis to fibronectin-coated surfaces. METHODS AND RESULTS: QCRS sensors (14 MHz) with 4 mm gold electrodes were coated with fibronectin and exposed for 15 min to suspensions of Staph. epidermidis ranging in concentration from 1 x 10(2) to 1 x 10(6) cfu ml(-1). Changes in resonant frequency were recorded and showed a linear relationship with the logarithm of cell concentration over the range tested. CONCLUSIONS: QCRS technology was shown to be a rapid, sensitive and non-destructive method for measuring the adhesion of bacteria to surfaces. SIGNIFICANCE AND IMPACT OF THE STUDY: This report demonstrates that QCRS technology has the potential to be used for a range of applications requiring measurement of bacteria on surfaces. In particular, it may be used for the real-time monitoring of bacterial biofilm formation.

Bacterial Adhesion↗
PubMed1985

The survival of Staphylococcus epidermidis in raw milk with different somatic cell count.

The antibacterial activity of an individual quarter milk sample cannot be evaluated by the number of somatic cells in milk and number of S. epidermidis cells surviving (-0,509, the most bactericidal. This was shown to be due to the fact that the strain of Staphylococcus epidermidis Se 25 is very sensitive to complement and also sensitive to cell free skimmed milk. A second stimulation of the udder enhances significantly the cell response to the stimulant. A negative and highly significant correlation coefficient exists between the number of somatic cells in milk and number of S. epidermidis cells surviving (0.509, P less than or equal to 0.01).

Animals↗
PubMed1996

Virulence of Staphylococcus epidermidis in a mouse model: significance of extracellular slime.

The ability to produce large quantities of biofilm on solid surfaces in vitro is believed to distinguish potentially pathogenic strains of Staphylococcus epidermidis from commensals. Biofilm consists of staphylococcal cells encased in a matrix of extracellular polysaccharide (also referred to as slime), firmly adherent to each other and to the underlying surface structure. The association of slime with colonization of catheter surfaces in vivo has been examined extensively. Less attention has been paid to the contribution of slime to infections that occur in the absence of an inserted device. In a mouse model of subcutaneous infection without an implanted device 10 S. epidermidis strains (5 slime-positive, 5 slime-negative) produced abscesses; thus a foreign body is not essential for the expression of virulence by S. epidermidis. Biofilm-positive strains produced significantly more abscesses, that persisted longer than biofilm-negative strains. In these chronic infections, large numbers of staphylococci were associated with macrophages and viable staphylococci were cultured from specimens of pus collected at autopsy. Thus slime or components of slime appear to delay the clearance of S. epidermidis from host tissues, possibly by interfering with intracellular killing mechanisms. However, differences in the capacity to produce abscesses, within both the slime-positive and slime-negative groups, indicate that other factors also contribute to the virulence of S. epidermidis.

Abscess↗
PubMed1995

Biomaterial-induced dysfunction in the capacity of rabbit alveolar macrophages to kill Staphylococcus epidermidis RP12.

The effect of poly(methyl methacrylate) (PMMA), titanium alloy, and silicone discs on the capacity of rabbit alveolar macrophages (AM) to kill RP12 strain of Staphylococcus epidermidis (RP12) was studied in vitro. When freshly harvested AM were preincubated with PMMA discs for 3 h and subsequently assayed for RP12 killing, there was no change in the RP12 killing capacity of AM. However, when AM were incubated with PMMA discs for 6 or 18 h at 37 degrees C in 5% CO2, the RP12 killing capacity of AM was reduced to 15% and 4%, respectively. Preincubation of AM with titanium alloy for 6 h reduced RP12 killing capacity of AM to 30%, and to 21% in 18-h incubation. Silicone discs did not affect the RP12 killing by AM at 6 h of preincubation, but reduced RP12 killing (35%) by AM when preincubated for 18 h. Preincubation of AM with PMMA discs for 3 or 6 h did not affect the level of PMA-elicited oxidative burst of AM as measured by a luminol-enhanced chemiluminescent assay. Superoxide dismutase, which eliminated the oxidative burst of AM by 90%, did not affect the RP12 killing by AM.

Animals↗
PubMed1998

The abilities of a Staphylococcus epidermidis wild-type strain and its slime-negative mutant to induce endocarditis in rabbits are comparable.

The abilities of a parent and mutant pair of Staphylococcus epidermidis strains, the slime-producing parent RP62A and its slime-negative mutant, to establish endocarditis in a rabbit model of aortic valve endocarditis and to accumulate and adhere to surfaces in vitro were compared. Vegetation titer and infection rate depended on the presence or absence of a catheter (P = 0.020) and on inoculum size (P < 0.001) but not on the infecting strain. The ability of the parent strain vis-à-vis its mutant to accumulate in vitro on surfaces as demonstrated in a slime test did not correlate with any enhancement in the development of endocarditis in the rabbit model. In vitro initial adherence rates were identical. Both isolates accumulated to the same reduced extent in vitro in the presence of serum, albumin, or gelatin. Adhesion was equally promoted by addition of fibronectin. These data suggest that the in vitro phenomenon of accumulation described as slime production in the absence of serum may not be an important virulence determinant in vivo.

Animals↗
PubMed1989

Pyogranulomatous pneumonias due to Nocardia asteroides and Staphylococcus epidermidis in two koalas (Phascolarctos cinereus).

Pyogranulomatous pneumonia was detected in two koalas (Phascolarctos cinereus). Nocardia asteroides was isolated from one koala with extensive pneumonia, pleurisy and splenitis. Staphylococcus epidermidis was isolated from a second koala with pneumonia restricted to the left cranial lobe. Both koalas were in poor condition and had underlying urogenital disease. It was concluded that each organism had acted as an opportunistic pathogen in its compromised host.

Animals↗
PubMed2000

The bacteriology of acne vulgaris and antimicrobial susceptibility of Propionibacterium acnes and Staphylococcus epidermidis isolated from acne lesions.

We examined the species of bacteria aerobically and anaerobically isolated from 30 acne lesions and determined antimicrobial susceptibilities of Propionibacterium acnes (P. acnes) and Staphylococcus epidermidis (S. epidermidis) using nine antimicrobial agents. Among the bacteria isolated, S. epidermidis was most dominant. Both P. acnes and S. epidermidis were isolated from half of the acne lesions. The MIC of seven antimicrobials (ampicillin, erythromycin, roxithromycin, clindamycin, tetracycline, minocycline, nadifloxacin) against P. acnes was under 3.13 micrograms/ml. There were very few resistant strains of P. acnes, but many of S. epidermidis. More than 30% of the S. epidermidis isolates were resistant to erythromycin, roxithromycin, and clindamycin. After long-term systemic antibiotic therapy, the resistant strains of S. epidermidis increased, but P. acnes resistance was still limited. When we use antimicrobial agents for the treatment of acne, it should be noticed that not only P. acnes but also S. epidermidis in the acne lesions may acquire resistance to antimicrobials.

Acne Vulgaris↗
PubMedDate not supplied

[Antibacterial activity of clindamycin and lincomycin in broth, serum, and in combination with polymorphonuclear leukocytes against Staphylococcus aureus and Staphylococcus epidermidis].

We investigated the antibacterial activity of clindamycin and lincomycin at 1/4 X minimum inhibitory concentration (MIC), 1 X MIC and 4 X MIC against a serum-resistant Staphylococcus aureus and a serum-resistant Staphylococcus epidermidis strain in broth, in serum with and without the presence of leukocytes and in Hank's medium in combination with leukocytes alone. Against both test strains, lincomycin in broth and serum was similarly effective, whereas against S. aureus clindamycin in broth was somewhat more active. In the combined test mixture of serum with leukocytes, even a 1/4 X MIC of clindamycin or lincomycin markedly improved leukocyte killing of S. aureus, whereas both compounds could not further enhance the marked leukocyte killing of S. epidermidis, even at inhibitory concentrations. In Hank's medium with leukocytes alone, clindamycin and lincomycin had at the most only a bacteriostatic effect against both test strains.

Blood↗
PubMed1996

The intercellular adhesin involved in biofilm accumulation of Staphylococcus epidermidis is a linear beta-1,6-linked glucosaminoglycan: purification and structural analysis.

The primary attachment to polymer surfaces followed by accumulation in multilayered cell clusters leads to biofilm production of Staphylococcus epidermidis, which is thought to contribute to virulence in biomaterial-related infections. We purified a specific polysaccharide antigen of biofilm-producing S. epidermidis 1457 and RP62A, which was recently shown to have a function in the accumulative phase of biofilm production by mediating intercellular adhesion (D. Mack, M. Nedelmann, A. Krokotsch, A. Schwarzkopf, J. Heesemann, and R. Laufs, Infect. Immun. 62:3244-3253, 1994). Following Sephadex G-200 gel filtration, this antigen was separated by Q-Sepharose chromatography into a major polysaccharide, polysaccharide I (> 80%), which did not bind to Q-Sepharose, and a minor polysaccharide, polysaccharide II (< 20%), which was moderately anionic. As shown by chemical analyses and nuclear magnetic resonance spectroscopy, polysaccharide I is a linear homoglycan of at least 130 beta-1,6-linked 2-deoxy-2-amino-D-glucopyranosyl residues. On average, 80 to 85% of them are N acetylated; the rest are non-N-acetylating and positively charged. Chain cleavage by deamination with HNO2 revealed a more or less random distribution of the non-N-acetylated glucosaminyl residues, with some prevalence of glucosaminyl-rich sequences. Cation-exchange chromatography separated molecular species whose content of non-N-acetylated glucosaminyl residues varied between 2 and 26%. Polysaccharide II is structurally related to polysaccharide I but has a lower content of non-N-acetylated D-glucosaminyl residues and contains phosphate and ester-linked succinate, rendering it anionic. Enzyme-linked immunosorbent assay inhibition with various monosaccharides revealed the beta-anomeric form and the acetylated amino group of the D-glucosaminyl residues as important for reactivity with the specific antiserum. The unbranched polysaccharide structure favors long-range contacts and interactions between polysaccharide strands and the cell wall and/or lectin-like proteins, leading to intercellular adhesion and biofilm accumulation. The structure of the polysaccharide is, so far, considered to be unique and, according to its function, is referred to as S. epidermidis polysaccharide intercellular adhesin (PIA).

Acetylglucosamine↗
PubMed1991

Effect of Staphylococcus epidermidis on adherence of Pseudomonas aeruginosa and Proteus mirabilis to polymethyl methacrylate (PMMA) and gentamicin-containing PMMA.

The goals of this study were to determine 1) effect of Staphylococcus epidermidis adherence and biofilm production on adherence of the opportunistic pathogens Proteus mirabilis and Pseudomonas aeruginosa to polymethyl methacrylate (PMMA); 2) if the biofilm killed by autoclaving altered adherence of other organisms; 3) if adherence of S. epidermidis to gentamicin-containing PMMA altered adherence of the opportunistic pathogens P. mirabilis and P. aeruginosa to gentamicin-containing PMMA. Results show that biofilms formed by S. epidermidis, whether alive or dead, significantly increased adherence of Pseudomonas. Adherence of Proteus was significantly increased on dead biofilms and increased, but not significantly (p = less than 0.1), on live ones. Greatest adherence seen in the study was to autoclaved biofilms. Significant adherence of Proteus and Pseudomonas was found on gentamicin-containing PMMA specimens, which were preincubated with S. epidermidis for formation on the biofilm. These results indicate that a biofilm is formed on PMMA-gentamicin specimens and this may impair the ability of gentamicin to kill other organisms.

Bacterial Adhesion↗
PubMed1995

[Antimicrobial activity in Staphylococcus epidermidis biofilms on polyvinyl chloride catheters].

OBJECTIVES: We have evaluated the effect of polyvinylchloride (PVC) catheters on the activity of eight antimicrobials. Secondly the activity of these antimicrobials against Staphylococcus epidermidis biofilms on PVC catheters was also studied. METHOD: The MIC and MBC values of amikacine, clindamycine, cloxacilline, ciprofloxacine, vancomycine, teicoplanine, daptomycine and rifampicine was evaluated by a microdilution assay in the presence of 0.5 cm length segments of PVC catheters. Catheter segments with bacteria attached for different periods of time were used as inocula for the studies of antimicrobial activity against bacterial biofilms. Both slime producing and non-producing strains were evaluated. RESULTS: The presence of PVC did not affect the activity of the antimicrobials evaluated against S. epidermidis. For the non-slime producing strains MBC values against sessile bacteria were significantly higher than those against planktonic bacteria. For the slime-producing strain MBCs of ciprofloxacine, amikacine and teicoplanine against both bacterial populations were similar. At high concentrations (16 x MBC), clindamycine was the only antimicrobial that sterilized non-slime producing S. epidermidis biofilms on PVC. Against the slime producing strains ciprofloxacine yielded the highest reduction on bacterial viability (99.9%). CONCLUSIONS: S. epidermidis biofilms on PVC were more resistant to antimicrobials than planktonic bacteria. Slime production is not the only factor involved in this phenomenon.

Anti-Bacterial Agents↗
PubMed1986

Naturally occurring Staphylococcus epidermidis plasmid expressing constitutive macrolide-lincosamide-streptogramin B resistance contains a deleted attenuator.

A naturally occurring constitutive macrolide-lincosamide-streptogramin B (MLS) resistance plasmid, pNE131, from Staphylococcus epidermidis was chosen to study the molecular basis of constitutive expression. Restriction and functional maps of pNE131 are presented along with the nucleotide sequence of ermM, the gene which mediates constitutive MLS resistance. Sharing 98% sequence homology within the 870-base-pair Sau3A-TaqI fragment, ermM appears to be almost identical to ermC, the inducible MLS resistance determinant from S. aureus (pE194). The two genes share nearly identical sequences, except in the 5' promoter region of ermM. Constitutive expression of ermM is due to the deletion of 107 base pairs relative to ermC; the deletion removes critical sequences for attenuation, resulting in constitutive methylase expression.

Amino Acid Sequence↗
PubMed1983

Detection of anti-teichoic acid immunoglobulin G antibodies in experimental Staphylococcus epidermidis endocarditis.

An enzyme-linked immunosorbent assay (ELISA) was developed for the detection of rabbit immunoglobulin G (IgG) antibodies to purified cell wall teichoic acids from the Staphylococcus aureus Lafferty strain and three strains of coagulase-negative staphylococci. Significant immunological cross-reactivity occurred only between the teichoic acid of S. aureus and one coagulase-negative preparation. The ELISA was used to determine the serum IgG response to Staphylococcus epidermidis in a rabbit model of aortic valve endocarditis. Blood samples were drawn before inoculation and then every 5 days until death or sacrifice at 32 to 35 days postinoculation. Valve vegetations were culture positive at autopsy in 16 (59%) of the 27 catheterized rabbits. Antibody titers in this culture-positive group and the culture-negative group began to rise as early as day 6. Although both groups demonstrated an antibody response, the culture-positive group attained a significantly higher titer on days 26 and 31. Antibodies also rose in a control group of rabbits without a heart catheter but which were inoculated with bacteria. Again, the antibody titer was significantly less than that for the culture-positive group. This ELISA may be useful for the diagnosis of coagulase-negative staphylococcal infections in humans.

Animals↗
PubMed2003

Expression of biofilm-associated genes in Staphylococcus epidermidis during in vitro and in vivo foreign body infections.

The expression of the genes icaA, icaC, aap, and atlE--with a putative role in the pathogenesis of Staphylococcus epidermidis foreign body infections--and of mecA and 3 housekeeping genes (gmk, tpi, and hsp60) was examined in vitro and in vivo. In vitro expression levels of ica, atlE, and gmk were higher in sessile than in planktonic bacteria. Exposure to foreign bodies in vitro and in vivo induced a sharp increase in ica expression that was followed by a progressive decrease. The in vivo expression of aap and mecA was high during early but low during late foreign body infections. The in vivo expression of atlE and gmk remained relatively high and stable. In conclusion, biofilm genes encoding for structural elements are mainly expressed during early foreign body infections. The ica genes are associated with initial colonization but not with persistence. The constant expression of atlE and gmk may indicate a role during the entire course of foreign body infections.

Animals↗
PubMed1999

Characterization of Staphylococcus epidermidis polysaccharide intercellular adhesin/hemagglutinin in the pathogenesis of intravascular catheter-associated infection in a rat model.

Biofilm production is thought to be a crucial factor in the ability of Staphylococcus epidermidis to produce a biomaterial-based infection. A rat central venous catheter (CVC)-associated infection model was used to assess the importance of biofilm production, mediated by polysaccharide intercellular adhesin/hemagglutinin (PIA/HA), in the pathogenesis of intravascular catheter-associated infection. PIA/HA-positive S. epidermidis 1457 was significantly more likely to cause a CVC-associated infection (71 versus 14%, P < 0.03) resulting in bacteremia and metastatic disease than its isogenic PIA/HA-negative mutant. These results confirm the importance of biofilm production, mediated by PIA/HA, in the pathogenesis of S. epidermidis experimental CVC-associated infection.

Animals↗
PubMed1991

Surface characteristics and adhesion of Escherichia coli and Staphylococcus epidermidis.

Surface hydrophobicity, surface electrokinetic potential and the ability to adhere to nitric-acid cleansed glass surfaces has been assessed throughout the growth, in batch culture, of Escherichia coli and Staphylococcus epidermidis. In both instances adhesiveness and surface hydrophobicity decreased in early- to mid-exponential phase. Cell surface charge, on the other hand became more electro-negative for E. coli but electro-neutral for Staph. epidermidis as the cells proceeded to divide. Adhesiveness correlated directly with surface electronegativity and hydrophobicity for Staph. epidermidis but inversely with surface electro-negativity for E. coli.

Bacterial Adhesion↗
PubMed2003

Comparative in vitro activity of linezolid and five other antimicrobials against nosocomial isolates of methicillin-resistant Staphylococcus aureus, methicillin-resistant Staphylococcus epidermidis and vancomycin-resistant Enterococcus faecium.

The activity of linezolid in comparison to vancomycin, teicoplanin, oxacillin, clindamycin and gentamicin was tested against 60 strains of methicillin-resistant Staphylococcus aureus, 60 strains of methicillin-resistant Staphylococcus epidermidis isolated from patients with nosocomial infections and 24 strains of vancomycin-resistant Enterococcus faecium isolated from feces of hospitalized patients. Minimum Inhibitory Concentrations (MICs) were determined by the Epsilometer test method. All tested strains were sensitive to linezolid and specifically all methicillin-resistant S. aureus had MIC range 0.25-3.00, MIC50 = 0.75, MIC90 = 1.5, all methicillin-resistant S. epidermidis had MIC range 0.125-1.5, MIC50 = 0.5, MIC90 = 1 and all vancomycin-resistant E. faecium had MIC range 0.5-1.5, MIC50 = 1, MIC90 = 1. Linezolid is the first of a novel antimicrobial class, the oxazolidinones, which is a promising treatment for serious Gram-positive infections, including multiresistant strains.

Acetamides↗