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Affinity of Staphylococcus epidermidis to various prosthetic graft materials.

BACKGROUND: Abdominal wall hernias have always been a major problem for general surgeons. The techniques of repairing primary, recurrent, and incisional hernias have evolved throughout the years at an accelerating trend, especially after production of prosthetic graft materials. Although looked upon with suspicion due to infection, fistula formation, and foreign body reaction, prosthetic graft materials are used deliberately in primary and recurrent hernias. The present study was designed to evaluate bacterial adherence to frequently used prosthetic graft materials. MATERIALS AND METHODS: The study was carried out in five different groups with each group consisting of 10 identical samples of the same kind of prosthetic graft material. The prosthetic graft materials used in the study were polypropylene, polyglactin 910, polyester fibers, steel, and polytetrafluoroethylene (PTFE). These prosthetic graft materials were incubated in vitro with a Staphylococcus epidermidis strain which was ++++ adhesion positive. The degree of adhesion of S. epidermidis to prosthetic graft materials was assessed by the ELISA method. RESULTS: Vicryl grafts showed significantly minimal bacterial adhesion whereas PTFE grafts tended to have more adhesion but this did not reach a statistical significance. Other graft materials did not show any difference for bacterial adhesion (Table 3). CONCLUSION: These results suggest that in vitro S. epidermidis adhesion to Vicryl grafts is less than other types of prosthetic graft materials (P < 0.05 for all comparisons). Further in vitro and in vivo studies are required to confirm these results and to understand the complex interactions among bacteria, graft material, microenvironment, and surgical technique.

Bacterial Adhesion↗

Combination antibiotic therapy in an outbreak of prosthetic endocarditis caused by Staphylococcus epidermidis.

The efficacy of combination antibiotics in vivo and in vitro was studied during an outbreak of prosthetic endocarditis caused by Staphylococcus epidermidis in 10 patients. The epidemic curve suggested that patients were infected at the time of their operation, with an interval from that time until diagnosis of 11 days to 20 months. The overall mortality was 50%. Four of six patients treated with gentamicin in combination with a penicillin analogue, a cephalosporin or clindamycin survived without reoperation. One of four patients survived when treated with regimens that did not include gentamicin. In vitro studies showed a median minimum inhibitory concentration for methicillin of 8.0 microgram/mL, compared with 0.1 microgram/mL for cephalothin, clindamycin and gentamicin, and a synergistic bactericidal effect between gentamicin and methicillin, cephalothin or clindamycin. These data suggest that gentamicin is a valuable component of combination antibiotic therapy in prosthetic endocarditis caused by S. epidermidis.

Adult↗

Susceptibility of Propionibacterium acnes and Staphylococcus epidermidis to killing by MPO-halide system products. Implication for taurine bromamine as a new candidate for topical therapy in treating acne vulgaris.

INTRODUCTION: Taurine chloramine (TauCl) and taurine bromamine (TauBr) are the main haloamines produced by activated neutrophils. TauCl exerts both anti-inflammatory and microbicidal activities. Clinical studies showed that TauCl may be useful as an antimicrobial agent in the local treatment of infections. Much less is known about TauBr. Circumstantial evidence suggests that Propionibacterium acnes (PA) has a role in the inflammation of acne. Available topical therapies include antimicrobial agents which reduce total PA numbers and anti-inflammatory agents which suppress activity of the cells present in acne inflammatory lesions. In this study the bactericidal activities of TauBr and TauCl against PA and Staphylococcus epidermidis (SE), as a control strain, were investigated. Moreover, the influence of these haloamines on the generation of reactive oxygen species (ROS) by activated neutrophils was also tested. MATERIALS AND METHODS: TauBr and TauCl were prepared by reaction of taurine with HOBr and HOCl, respectively. The reaction was monitored by UV absorption spectra. The bactericidal activities of TauBr and TauCl were determined by the pourplate method. The generation of ROS by neutrophils was determined by luminol chemiluminescence assay. RESULTS: In our experimental set-up, TauBr showed stronger antibacterial activity than TauCl. Interestingly, PA was significantly more susceptible to TauBr than SE was. Moreover, TauBr at non-cytotoxic concentrations significantly reduced ROS generation by neutrophils. CONCLUSIONS: Since PA is considered to be an etiological agent in acne and ROS are closely correlated with the pathogenesis of inflammatory skin diseases, the reported data suggest that TauBr may be a good candidate for the topical therapy for acne vulgaris.

Acne Vulgaris↗

Mechanisms of inhibition by fluoride of urease activities of cell suspensions and biofilms of Staphylococcus epidermidis, Streptococcus salivarius, Actinomyces naeslundii and of dental plaque.

BACKGROUND/AIMS: Fluoride is known to be a potent inhibitor of bacterial ureases and can also act in the form of hydrofluoric acid as a transmembrane proton conductor to acidify the cytoplasm of intact cells with possible indirect, acid inhibition of urease. Our research objectives were to assess the inhibitory potencies of fluoride for three urease-positive bacteria commonly found in the mouth and to determine the relative importance of direct and indirect inhibition of ureases for overall inhibition of intact cells or biofilms. METHODS: The experimental design involved intact bacteria in suspensions, mono-organism biofilms, cell extracts, and dental plaque. Standard enzymatic assays for ammonia production from urea were used. RESULTS: We found that ureolysis by cells in suspensions or mono-organism biofilms of Staphylococcus epidermidis, Streptococcus salivarius or Actinomyces naeslundii was inhibited by fluoride at plaque levels of 0.1-0.5 mm in a pH-dependent manner. The results of experiments with the organic weak acids indomethacin and capric acid, which do not directly inhibit urease enzyme, indicated that weak-acid effects leading to cytoplasmic acidification are also involved in fluoride inhibition. However, direct fluoride inhibition of urease appeared to be the major mechanism for reduction in ureolytic activity in acid environments. Results of experiments with freshly harvested supragingival dental plaque indicated responses to fluoride similar to those of S. salivarius with pH-dependent fluoride inhibition and both direct and indirect inhibition of urease. CONCLUSION: Fluoride can act to diminish alkali production from urea by oral bacteria through direct and indirect mechanisms.

Actinomyces↗

Increased risk of Staphylococcus epidermidis peritonitis in patients on dialysate containing 1.25 mmol/L calcium.

Peritoneal macrophage function is decreased in vitro in the presence of dialysate with 1.25 mmol/L calcium compared with that containing 1.75 mmol/L calcium. Theoretically, patients using this dialysate may have a higher risk of peritonitis. Nineteen patients on continuous ambulatory peritoneal dialysis (CAPD) or continuous cycling peritoneal dialysis (CCPD) were converted from dialysate with 1.75 mmol/L calcium (mean time, 33 +/- 26 months) to that with 1.25 mmol/L calcium, for some or all exchanges (mean time, 10 +/- 4.7 months). Peritonitis rates were compared with 19 control patients who remained on dialysate with 1.75 mmol/L calcium. The two groups were matched for the proportion of diabetics, sex, age, use of the Y-set, and dialysis modality (CAPD, CCPD). Peritonitis rates were similar in the study patients before conversion to 1.25 mmol/L calcium dialysate and in the control patients (0.49 v 0.58 episodes/patient-year, respectively). After conversion to dialysate with 1.25 mmol/L calcium, the peritonitis rate was 0.82 episodes/patient-year contrasted to 0.58 episodes/patient-year in the control patients (P = 0.09). The peritonitis rate due to Staphylococcus epidermidis was 0.51 episodes/patient-year when 1.25 mmol/L calcium dialysate was used, and 0.19 episodes/patient-year for the comparable period in the control patients on 1.75 mmol/L calcium dialysate (P = 0.005). The proportion of peritonitis episodes due to S epidermidis increased from 20% to 61% after conversion to 1.25 mmol/L calcium (P = 0.01). The increased risk of peritonitis due to S epidermidis in patients using dialysate with 1.25 mmol/L calcium is consistent with a previous study demonstrating that clearance of S epidermidis by peritoneal macrophages is less effective with a decrease in the dialysate calcium content.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

In vivo efficacy of silver-coated (Silzone) infection-resistant polyester fabric against a biofilm-producing bacteria, Staphylococcus epidermidis.

BACKGROUND AND AIMS OF THE STUDY: Prosthetic valve endocarditis (PVE) is an infrequent but serious complication of cardiac valve replacement. PVE is a foreign body infection predominantly based in the sewing cuff of a prosthetic heart valve leading to thromboembolism, ring abscess, paravalvular leakage, and eventual invasion of the myocardium. Mortality rates as high as 75% have been reported. A silver-coated sewing cuff is now available (St. Jude Medical mechanical heart valve SJMR Masters Series with Silzone coating) intended to inhibit the colonization and attachment to the sewing cuff of those microorganisms commonly associated with PVE. Silzone is a dense layer of metallic silver deposited on individual fiber surfaces of the valve cuff. Previously, Silzone coating was shown in vitro to decrease attachment and colonization of microorganisms with no adverse affect on biocompatibility. The present study was designed to assess the efficacy of Silzone-coated polyester fabric in vivo in a direct-contamination model. The organism chosen was a pathogenic strain of Staphylococcus epidermidis capable of producing biofilm. METHODS: Infection resistance of uncoated polyester and Silzone-coated polyester fabric was assessed by the acute inflammatory response in a guinea pig subdermal model. Fabric samples were implanted sterile or inoculated with S. epidermidis. The ability of the strain to produce biofilm was verified in vitro. Samples were explanted at one and two days postoperatively. Verification of the infecting bacteria was by colony morphology and Gram-staining properties of bacteria from the explanted samples. Inflammation was assessed histopathologically. Percent necrotic tissue within the fabric was determined by computer-assisted image analysis. RESULTS: Histopathology and image analysis of necrotic tissue showed significantly less inflammation within the Silzone-coated fabric than within uncoated polyester fabric. CONCLUSIONS: The Silzone coating reduced inflammation in this direct-contamination model using a strain of S. epidermidis that is capable of producing biofilm. This indicates a concentration of silver ions sufficient for bacteriostatic or bactericidal activity within the fabric in vivo.

Animals↗

Conjugational transfer of gentamicin resistance plasmids intra- and interspecifically in Staphylococcus aureus and Staphylococcus epidermidis.

We have previously reported the transfer of gentamicin resistance (Gmr) plasmids in a mixed culture inter- and intraspecifically between strains of Staphylococcus aureus and Staphylococcus epidermidis isolated at Michael Reese Hospital (Jaffe et al., Antimicrob. Agents Chemother. 21:773-779, 1982). We have now shown that representatives of these plasmids were transferred between apparently nonlysogenic strains of S. aureus either in mixed culture in broth or by filter-mating on agar medium. The mechanism of transfer appeared to be conjugation. A transferable Gmr plasmid (pSH8) mobilized or cotransferred a tetracycline R-plasmid and a chloramphenicol R-plasmid that were not independently transferable. The transfer of Gmr plasmids was accompanied by a high incidence of deletion mutations with varied loss of plasmid resistance determinants and, with some mutants, loss of the ability to effect self-transfer. Restriction endonuclease digestion of pSH8 and its deletion mutants made it possible to assign the property of self-transfer to a specific segment of the pSH8 genome and provided the basis for a physical and genetic map of that plasmid. Similar Gmr plasmids from S. aureus strains isolated in locations remote from Michael Reese Hospital had resistance determinants and transfer properties comparable to those of pSH8. Our observations provide evidence for the conjugal transfer of some staphylococcal plasmids, apparently independent of the presence of phage. This mechanism may be of significance in the intra- and interspecific dissemination of resistance to aminoglycosides and other antibiotics in Staphylococcus spp.

Chromosome Mapping↗

Staphylococcus epidermidis causing prosthetic valve endocarditis: microbiologic and clinical observations as guides to therapy.

Seventy-five episodes of prosthetic valve endocarditis from Staphylococcus epidermidis were studied retrospectively. Methicillin-resistant isolates caused 53 (87%) of 61 infections occurring within 1 year of surgery but only two of the nine after 1 year (p less than 0.001). Resistance to methicillin was heterogeneic and extended to the cephalosporins. Of 55 isolates, 43 (78%) were susceptible to gentamicin and all to vancomycin and rifampin. In 55 patients, prosthetic valve endocarditis was complicated by tissue invasion or valve dysfunction. Among these 55 patients, 30 of the 32 who were cured needed surgery. Prosthetic valve endocarditis from methicillin-resistant S. epidermidis was cured in 21 of 26 patients treated with vancomycin and 10 of 20 treated with beta-lactam antibiotic therapy (p = 0.055). Cure rates of patients treated with vancomycin but not beta-lactam antibiotics were increased by the addition of rifampin or gentamicin to therapy. Prosthetic valve endocarditis from methicillin-resistant S. epidermidis should be treated with vancomycin plus rifampin, or an aminoglycoside. Surgical intervention is important in treating complications of prosthetic valve endocarditis.

Adolescent↗

Differentiation by electrophoresis and enzymoserology of proteinases, produced by strains of Staphylococcus epidermidis biotypes 1 and 4.

Electrophoretic and serologic characterization of extracellular proteinases from 111 isolates (80 biotype 1 and 31 biotype 4) of Staphylococcus epidermidis (coagulase negative) of human origin were conducted. Seventy-seven (60 of biotype 1, 17 of biotype 4) of the 111 proteinase-positive isolated of S. epidermidis were classified by serological differentiation of their proteolytic enzymes with known specific antisera. Thirty-two (18 of biotype 1, 14 of biotype 4 (isolates of S. epidermidis produced proteolytic enzymes that did not react with any of the known group antisera and were classified as NR (non-reacting). No classification of the enzymes of two other isolates was possible. The NR proteinase enzymes from the 32 cultures that could not be classified by serological differentiation with the known specific antisera fitted into one of three electrophoretic mobility patterns: NR1, NR2 or NR3. Seventy-eight isolates of S. epidermidis biotype 1 were placed into four proteinase sero-groups; 49 in F, 11 in B, 11 in NR2, and 7 in NR3. Thirty-one isolates of S. epidermidis biotype 4 were placed into one of two groups: 17 in C and 14 in NR. All enzymes tested migrated towards the anode at pH 8.6, and the order of electrophoretic mobility was NR3 greater than F greater than NR2 greater than NR1 greater than B greater than C.

Caseins↗

Immunological response to a strain of Staphylococcus epidermidis in the rabbit: production of protective antibody.

A rabbit was immunised with a heat-killed vaccine prepared from strain 1142 of Staphylococcus epidermidis. The HA titres of the antisera against a surface-polysaccharide antigen extracted from the homologous strain were highest in the 2nd-4th weeks after immunisation and subsequently declined. Only a minor amount of 2-ME-resistant antibody was formed, and this at a late state of the reaction. After a booster injection of the vaccine at the 10th week, there was a significantly greater HA-antibody response and a greater amount of 2-ME-resistant antibody was formed. The relative passive-protective activity of the sera in mice corresponded to their content of 2-ME-sensitive HA antibody. The protective activity of the sera was 2-ME sensitive and was not removed by absorption with anti-rabbit IgG goat serum. Further, 280 microgram of IgM-rich serum fraction obtained by sucrose-density-gradient ultracentrifugation passively protected against homologous challenge infection in mice, but even 910 microgram of IgG-rich fraction did not. These results indicated that the protective antibody was of the IgM class.

Animals↗

On chronic prostatitis with special studies of Staphylococcus epidermidis.

Patients with chronic prostatitis have an increased number of white blood cells in expressed prostatic secretion. Two groups can be separated, one is characterized by uropathogenic bacteria in expressed prostatic secretion and recurrent urinary tract infections, chronic bacterial prostatitis. In this group an immune response to the bacteria has been demonstrated. Patients belonging to the other group, non-bacterial prostatitis, have similar symptoms. Many harbour Gram-positive bacteria in a high number, often Staphylococcus epidermidis in expressed prostatic secretion. This bacteria is usually not considered in prostatitis in spite of extreme high numbers. The etiology of non-bacterial inflammations is thus unknown. Forty-three per cent of the patients with chronic prostatitis had Gram-positive bacteria and 13% had Gram-negative in expressed prostatic secretion. Forty-four per cent of patients referred with symptoms of prostatitis did not have any aerobic bacteria at the prostatic level in sufficient number for the diagnosis bacterial prostatitis according to Meares and Stamey and form thus a third group. Antibiotic treatment of patients with non-bacterial prostatitis reduced symptoms but also changed the bacterial flora in urethral and prostatic secretion in such a way that uropathogens were found after treatment. In a group of patients an immunologic response to Staph. epidermidis was searched for by measuring complement components (C3c, C4c) as well as ceruloplasmin in serum and immunoglobulins (IgA, IgG) in seminal plasma. A specific ELISA method to estimate antibodies in serum against Staph. epidermidis was tested. No specific pattern separated patients from controls or patients with Gram-negative bacteria from patients with Gram-positive bacteria. Staphylococcus saprophyticus in cultures from men with prostatitis were more frequent in the third quarter of the year. The bacteria seemed to appear during or after antibiotic treatment but disappeared spontaneously during a follow-up period of six months. Treatment with the surfactant sodium pentosanpolysulphate, a heparinoid, given orally to patients with chronic prostatitis reduced concomitant pain in muscles and joints. The possibility of an altered host factor function in the polymorphonuclear leucocytes of patients with chronic non-bacterial prostatitis colonized with Staph. epidermidis was investigated. Chemotaxis, phagocytosis and intracellular killing were reduced in vitro and may to a part explain the bacteriological findings. Careful evaluations must thus be performed of earlier neglected factors to reach better knowledge of the chronic prostatitis.

Adult↗

[Staphylococcus epidermidis infective endocarditis after mitral surgery, successfully treated with aspirin and antibiotics: a case report].

We report a case of infectious endocarditis from Staphylococcus epidermidis that occurred early after mitral valve repair (one month), suggested by fever of 38.5 degrees C and valvular vegetations of less than 10 mm on the mitral valve. In the absence of standard recommendations (medical or surgical) in treating patients with infectious endocarditis occurring after mitral valve repair, and in the absence of complications, a medical regimen was chosen associating aspirin (anti-aggregant dosages) with antibiotics. The benefit of aspirin in endocarditis has been demonstrated in experimental studies with regards to valvular vegetations and embolic risk but remains to be studied in human clinical trials. With the association of aspirin (100 mg/d) and triple antibiotic therapy (rifampicin 1200 mg/d, vancomycin 2 g/d, gentamycin 180 mg/d), the clinical status improved with complete regression of vegetations in less than 24 days and the absence of recurrence at one-year follow-up.

Adult↗

Mouse virulent strain of Staphylococcus epidermidis. Relation of antiphagocytic activity to the protection-inducing antigen.

Using 10(9) or 10(7) 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.

Amino Acids↗

Universal versus targeted chlorhexidine and mupirocin decolonisation and clinical and molecular epidemiology of Staphylococcus epidermidis bloodstream infections in patients in intensive care in Scotland, UK: a controlled time-series and longitudinal genotypic study.

BACKGROUND: There are concerns that biocide skin and mucous membrane decolonisation, which is widely used to prevent health-care-associated infections in intensive care units (ICUs), might select for multidrug-resistant pathogens. We aimed to evaluate the effects of de-escalating from universal to targeted skin and nasal decolonisation on Staphylococcus epidermidis bloodstream infections (SE-BSI). METHODS: We did a retrospective, before-after-control-impact time-series analysis and longitudinal genotypic study in two ICUs with divergent decolonisation practice in tertiary care hospitals of adjacent health boards in Scotland, UK. Participants were aged at least 16 years and admitted between July 1, 2009, and Feb 28, 2022. There were no exclusion criteria for the study. In ICU one (intervention site) universal decolonisation in all admissions was de-escalated to targeted decolonisation of meticillin-resistant Staphylococcus aureus (MRSA) carriers on Feb 1, 2019, while in ICU two (control site) targeted decolonisation was applied throughout. We collected bloodstream infection data from all causes, including clinically significant SE-BSI. Antimicrobial susceptibility testing was used to define meticillin-resistant S epidermidis (MRSE) and chlorhexidine susceptibility. We used multilocus sequence typing to identify sequence types from archived SE-BSI isolates. Whole-genome sequencing was applied to a sample from ICU one. The primary outcomes were incidence densities of all bloodstream infections, SE-BSI, and meticillin-resistant S epidermidis bloodstream infections (MRSE-BSI), and the percentage probability that SE-BSI were MRSE-BSI. The effects of de-escalation on primary outcomes were estimated by differences between the intervention and control sites, before and after de-escalation, using a before-after-control-impact time-series design. Secondary outcomes included the proportion of multidrug resistant sequence types, carriage of mobile genetic elements and genes for multidrug resistance and biofilm production. FINDINGS: Between July 1, 2009, and Feb 28, 2022, S epidermidis was identified in 334 (45%) of 735 bloodstream infections in ICU one, of which 197 occurred before the de-escalation intervention in Feb 1, 2019, and S epidermidis was identified in 167 (60%) of 278 bloodstream infections in ICU two. There was no increase in all bloodstream infection incidence coinciding with de-escalation in ICU one, whereas MRSE-BSI incidence declined significantly from 10&#xb7;4 cases per 1000 occupied bed days (OBDs; 95% credible interval [CrI] 7&#xb7;2-15&#xb7;4) to 4&#xb7;3 cases per 1000 OBDs (2&#xb7;5-6&#xb7;7), as did the percentage probability of MRSE (from 89&#xb7;2%, 95% CrI 77&#xb7;8-96&#xb7;5 to 56&#xb7;7%, 34&#xb7;3-77&#xb7;5%). No significant changes in the primary outcomes were seen in ICU two. MRSE-BSI incidence density was positively associated with chlorhexidine use, but not mupirocin use. De-escalation was associated with a reduced proportion of SE-BSI due to multidrug-resistant sequence types and reduced carriage of mobile genetic elements and genes for multidrug resistance and biofilm production, as observed by multi-locus sequence typing and whole genome sequencing. INTERPRETATION: In ICU settings with low MRSA incidence, the benefits of universal decolonisation should be balanced against the risks of selecting MRSE sequence types adapted for invasive and device-associated infection. FUNDING: National Health Service Grampian Charity.

Humans↗

The adherence of Staphylococcus epidermidis to human tonsil lymphocytes.

Attachment of various bacteria to human, peripheral blood and tonsil lymphocytes was investigated in vitro. About 20% of tonsil lymphocytes bound Staphylococcus epidermidis, whereas the binding of other strains was negligible. The influence on cytoadherence of human serum, immunoglobulins (human IgM, IgG, IgA, as well as their respective anti-Ig's), and carbohydrates (mono and polysaccharides) was measured. It was found that heterogenous surface structures of the lymphocytes participate in the attachment.

B-Lymphocytes↗

Cytotaxin production by comedonal bacteria (Propionibacterium acnes, Propionibacterium granulosum and Staphylococcus epidermidis).

The potential role of different species of comedonal bacteria as chemotactic stimuli in the inflammatory phase of acne vulgaris was investigated by comparing 12 strains of Staphylococcus epidermidis, 11 strains of Propionibacterium acnes, and 5 strains of P. granulosum for production of cytotaxin in vitro. Results indicated that not only were there marked differences in cytotaxin production between different strains of the same species grown under identical growth conditons, but there were often significant differences in cytotaxin activity of the same strain grown in different media. This finding is discussed in relation to development of inflammation in quiescent comedones in acne vulgaris.

Acne Vulgaris↗

Common antibiotic resistance plasmids in Staphylococcus aureus and Staphylococcus epidermidis from human and canine infections.

The plasmids of a multiresistant "canine" Staphylococcus epidermidis-culture were investigated. Two small plasmids, the 4.55 kB chloramphenicol resistance (CmR-) plasmid pSC4 and the 4.45 kB tetracycline resistance (TetR-) plasmid pST 3 could be isolated. Detailed restriction maps of pSC 4 and pST 3 were constructed by double restriction endonuclease digests. The restriction maps revealed extensive structural homologies between pSC 4 from "canine" S. epidermidis and the CmR-plasmid pC 221 from "human" S. aureus as well as between pST 3 from "canine" S. epidermidis and the TetR-plasmid pT 181 from "human" S. aureus. These data suggested that an exchange of small plasmids between S. epidermidis and S. aureus might be possible.

Animals↗