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PubMed1983

Chemical composition and structure of cell wall teichoic acids of staphylococci.

The cell wall teichoic acid structures of 22 staphylococci including 13 type strains were determined. Most of the strains contain a poly(polyolphosphate) teichoic acid with glycerol and/or ribitol as polyol component. The polyolphosphate backbone is partially substituted with various combinations of sugars and/or amino sugars. Most of the substituents occur in a monomeric form but some strains also contain dimers of N-acetylglucosamine as substituents. Staphylococcus hyicus subsp. hyicus NCTC 10350 and S. sciuri DSM 20352 revealed rather complex cell wall teichoic acids. They consist of repeating sequences of phosphate-glycerol-phosphate-N-acetylglucosamine. The amino sugar component is present in this case as a monomer or an oligomer (n less than or equal to 3). Moreover, the glycerol residues are partially substituted with N-acetylglucosamine. The cell wall teichoic acid of S. auricularis is a poly(N-acetylglucosaminyl-phosphate) polymer similar to that found in S. caseolyticus ATCC29750. The cell wall teichoic acid structures for type strains of S. auricularis, S. capitis, S. cohnii, S. haemolyticus, S. hominis, S. hyicus subsp. hyicus, S. sciuri, S. xylosus and S. warneri were determined for the first time in detail. The structures of some of the previously described teichoic acids had to be revised (S. epidermidis, S. simulans, S. aureus phage type 187).

Acetylglucosamine↗

PubMed2006

Prevalence and antibiotic resistance of 15 minor staphylococcal species colonizing orthopedic implants.

Several species belonging to Staphylococcus genus (non Sau/ non Sep species) exhibit increasing abilities as opportunistic pathogens in colonisation of periprosthesis tissues. Here we report on antibiotic resistance of 193 strains, belonging to non Sau/ non Sep species, consecutively collected from orthopedic implant infections in a period of about 40 months. The 193 strains (representing 17% of all staphylococci isolated) were analysed for their antibiotic resistance to 16 different drugs. Five species turned out more prevalent, ranging from 1 to 5%: S. hominis (4.2%), S. haemolyticus (3.7%), S. capitis (2.7%), S. warneri (2.6%), and S. cohnii (1.6%). Among these, the prevalence of antibiotic resistance to penicillins was similar, ranging from 51% to 66%. Conversely, significant differences were observed for all the remaining antibiotics. For S. haemolyticus the resistances to oxacillin and imipenem, the four aminoglycosides and erythromycin were at least twice that of the other three species which were compared. S. warneri was on the contrary the species with the lowest occurrence of resistant strains. Ten species appeared only rarely at the infection sites: S. lugdunensis, S. caprae, S. equorum, S. intermedius, S. xylosus, S. simulans, S. saprophyticus, S. pasteuri, S. sciuri, and S. schleiferi. The behaviours of these species, often resistant to penicillins, were individually analysed. Differences in both the frequencies and the panels of antibiotic resistances observed among the non Sau/ non Sep species: i) suggest that horizontal spreading of resistance factors, if acting, was not sufficient per se to level their bio-diversities; ii) highlight and confirm the worrisome appearance within the Staphylococcus genus of emerging ""new pathogens"", not homogeneous for their virulence and antibiotic resistance prevalence, which deserve to be recognised and treated individually.

Anti-Bacterial Agents↗

PubMed1998

Antimicrobial resistance in staphylococci and enterococci in 10 Portuguese hospitals in 1996 and 1997. POSGAR. Portuguese Study Group of Antimicrobial Resistance.

During a 2-year period, 10 Portuguese hospitals located throughout the country studied antimicrobial susceptibilities of clinically relevant staphylococci and enterococci. Of more than 12,000 Staphylococcus aureus isolates tested, two main patterns were found, methicillin-sensitive organisms most of them resistant only to penicillin but a few to other antimicrobials and methicillin-resistant S. aureus (MRSA) strains (prevalence 48.2%) resistant to most of the antimicrobials tested and uniformly susceptible to vancomycin. Among coagulase-negative staphylococci (CNS), 71% of S. epidermidis (approximately 5,000 isolates tested) and 84% S. haemolyticus (approximately 1,000 isolates tested) were also resistant to methicillin as well as most other antimicrobials except vancomycin. Most of the 5,000 Enterococcus faecalis isolates tested were susceptible to ampicillin and vancomycin, in contrast to 650 E. faecium isolates, 70% of which were resistant to ampicillin and 20% to vancomycin and all other antibiotics. A high prevalence of aminoglycoside resistance occurred in both Enterococcus species. This survey showed that resistance profiles of staphylococci and enterococci hospital isolates have not changed in the last 5 years in Portugal, with the exception of the rise in vancomycin resistance in E. faecium. The high prevalence of methicillin resistance in S. aureus and in the CNS remains an issue of medical concern.

Anti-Bacterial Agents↗

PubMed1995

Biomaterial-associated staphylococcal peritoneal infections in a neutropaenic mouse model.

Adhesion of staphylococcal cells to polyethylene with end point-attached heparin was quantified by bioluminescence. Staphylococcus epidermidis 3380 and the slime-producing S. epidermidis RP12 adhered to the highest extent, and S. lugdunensis 2342 to the least extent. Preincubation of the polymer with dialysis fluid reduced adhesion of S. epidermidis 3380 and RP12 but enhanced that of S. aureus, and preadsorption of the surface with fibronectin decreased subsequent adhesion of S. epidermidis and S. haemolyticus strains. When staphylococci were grown in the presence of a biomaterial their ability to activate peritoneal cells was decreased. The bactericidal activity was impaired, whereas ingestion of opsonized coagulase-negative staphylococci (CNS) strains was unaffected. With S. epidermidis RP12 the presence of biomaterial did not influence either phagocytosis or bactericidal effect of peritoneal cells. After intra-peritoneal challenge with staphylococcal strains, the organ uptake of S. aureus Cowan 1 was increased in normal mice whereas immunosuppressed mice died. CNS strains increased mainly in the peritoneal cavity of immunosuppressed mice. The uptake of bacteria in liver and kidneys was increased with S. epidermidis 3380, S. lugdunensis 2343 and S. schleiferi 667-88. Generally, CNS strains persisted in the peritoneal cavity of both normal and immunosuppressed mice. These data indicate that host defense mechanisms, mainly polymorphonuclear neutrophils, fail to eliminate CNS infections in the peritoneum, and that initial adhesion to an implanted biomaterial may be of lesser importance in the peritoneal cavity than in e.g. catheter-associated infections. There are strain-specific virulence factors of bacteria, and slime producing strains evade the host defense mechanisms more efficiently than non-slime producing strains.

Adsorption↗

PubMed2003

Design and evaluation of specific PCR primers for rapid and reliable identification of Staphylococcus xylosus strains isolated from dry fermented sausages.

Rapid and reliable identification of Staphylococcus xylosus was achieved by species-specific PCR assays. Two sets of primers, targeting on xylulokinase (xylB) and 60 kDa heat-shock protein (hsp60) genes of S. xylosus, respectively, were designed. Species-specificity of both sets of primers was evaluated by using 27 reference strains of the DSM collection, representing 23 different species of the Staphylococcus genus and 3 species of the Kocuria genus. Moreover, 90 wild strains isolated from different fermented dry sausages were included in the analysis. By using primers xylB-F and xylB-R the expected PCR fragment was obtained only when DNA from S. xylosus was used. By contrast, amplification performed by using primers xylHs-F and xylHs-R produced a single PCR fragment, of the expected length, when DNA from S. xylosus, S. haemolyticus, S. intermedius and S. kloosii were used as template. Nevertheless, AluI digestion of the xylHs-F/xylHs-R PCR fragment allowed a clear differentiation of these 4 species. The rapidity (about 4 h from DNA isolation to results) and reliability of the PCR procedures established suggests that the method may be profitably applied for specific detection and identification of S. xylosus strains.

Bacterial Proteins↗

PubMed2003

Isolation of methicillin-resistant coagulase-negative staphylococci from patients undergoing continuous ambulatory peritoneal dialysis (CAPD) and comparison of different molecular techniques for discriminating isolates of Staphylococcus epidermidis.

Coagulase-negative staphylococci (CNS) have emerged as an important pathogen in nosocomial infections. About 80%-90% of CNS isolates associated with hospital infections are methicillin-resistant coagulase-negative staphylococci (MRCNS). The aims of this study were to screen for MRCNS isolates in the flora of a small population of patients undergoing continuous ambulatory peritoneal dialysis (CAPD) and to evaluate the discriminatory power of different molecular methods: pulsed-field gel electrophoresis (PFGE), mecA location, ClaI/mecA polymorphism and arbitrarily primed polymerase chain reaction (AP-PCR) for characterizing isolates of methicillin-resistant Staphylococcus epidermidis (MRSE). Seventy-nine CNS isolates were recovered from the 11 CAPD patients studied. Using a methicillin screening agar and a DNA specific mecA probe we verified that 30 of the 79 (38%) CNS isolates were resistant to methicillin (MRCNS). Twenty-two of the 30 MRCNS (73%) were MRSE, 7 (23%) methicillin-resistant S. haemolyticus (MRSH(ae)) and 1 (3%) methicillin-resistant S. hominis (MRSH(om)). All patients analyzed carried MRCNS in their flora, in one or more sites. Since CAPD patients have high risk for developing peritonitis, the colonization of these patients with MRCNS might represent an additional problem, due to the therapeutic restrictions imposed by these multiresistant isolates. A wide genetic diversity was verified when the PFGE of the MRSE isolates was analyzed. The 22 MRSE isolates displayed a total of 15 PFGE different patterns (11 PFGE types and 4 subtypes). The location of mecA in the SmaI-fragmented genome DNA did not bring any additional advantage for epidemiologic characterization of the isolates. The ClaI/mecA polymorphism was able to correctly discriminate 12 from the 15 PFGE patterns. In addition, the DNA of 20 MRSE isolates were used for AP-PCR typing. These isolates belonged to 14 PFGE patterns (11 types and 3 subtypes) and displayed 15 genotypes (for the association of PFGE, mecA location and ClaI/mecA polymorphism). A total of 17 different amplification patterns was verified using the primer 1. Only for 2 genotypes, strains having identical genetic backgrounds were further discriminated by AP-PCR (2 of 15 genotypes (87%) for AP-PCR and 1 of 15 genotypes for PFGE; (93%). Concluding, our results indicated that the AP-PCR can be an alternative and useful tool for monitoring and genotyping MRSE colonization and also to molecular characterizing MRSE outbreaks in hospitals.

Anti-Bacterial Agents↗

PubMed1981

Cellular fatty acid composition in staphylococci isolated from bovine milk.

Cellular fatty acid composition was examined in 61 strains of coagulase-negative staphylococci of bovine milk origin and 19 strains of Staphylococcus aureus and S. epidermidis serving as reference strains. The 61 strains had been divided into 9 species in accordance with the classification of Kloos & Schleifer. When S. aureus and the coagulase-negative staphylococci were examined, they contained iso-C15:0, anteiso-C15:0, C18:0, and C20:0 as main fatty acids. There was no marked difference in the cellular fatty acid composition between any two staphylococcal species. The percent cellular fatty acid composition of each species was regarded as one of the quantities of continuity and subjected to the analysis of variance by the unary configuration method. As a result, S. capitis, S. cohnii, S. epidermidis, and S. xylosus seemed to have a cellular fatty acid composition a little different from that of any other species. When similarity values among all the strains were calculated, they were 0.89 or more and made it possible to divide all the strains into two large groups at the similarity value of 0.90. In the one group the iso-C15:0 was a characteristic fatty acid. In the other group the anteiso-C15:0 was a characteristic fatty acid. To the first group belonged S. hyicus and S. lentus. To the second group belonged S. cohnii, S. epidermidis, S. haemolyticus, S. hominis, S. saprophyticus, and S. warneri. In the two groups were distributed S. aureus, S. capitis, S. simulans, and S. xylosus.

Animals↗

PubMedDate not supplied

[Role of Staphylococcus saprophyticus in urinary infections].

A proportion of S. saprophyticus in other coagulase-negative staphylococcal isolates from the urine of patients with urinary infections and healthy individuals has been investigated. Certain diagnostic aspect of the urinary infections with S. saprophyticus have also been considered. Hundred four coagulase-negative staphylococcal strains isolated from patients in Słupsk and Gdańsk area and 72 strains of the coagulase-negative staphylococci isolated from the urine of healthy women have been divided into 9 species, according to Kloos and Schleifers' classification. Bacteriologic tests have shown that S. saprophyticus produced 20.4% of the urinary tract infections in Słupsk area holding the second place after S. haemolyticus (27.3%). This species was the most infrequent in the urine of patients in Gdańsk area (3.3%). Its sensitivity to antibiotics did not differ from that of other coagulase-negative staphylococci. In contrast to the majority of other strains, S. saprophyticus has not been isolated from the urinary tract of healthy women and has been encountered most frequently in low bacteriuria. Test of resistance to novobiocin which is considered as a simplified identification method of this species proved to be not very precise as other species have also been resistant to this antibiotic.

Coagulase↗

PubMed1983

Numerical taxonomy of staphylococci.

Over two hundred staphylococci from human and animal sources and representatives of established species of Staphylococcus, Micrococcus and Planococcus were compared in a numerical phenetic survey using 115 unit characters. Data were analyzed using the Jaccard coefficient and the unweighted pair group method with averages algorithm. Cluster composition was not markedly affected by test error, estimated as 3.49%. The staphylococci were assigned to eighteen clusters containing four or more strains and to three single member clusters. Most of the clusters were distinct and homogeneous though two were divided into subclusters. Some of the clusters and subclusters were equated with the established taxa S. aureus, S. capitis, S. cohnii, S. epidermidis, S. haemolyticus, S. hominis, S. hyicus, S. saprophyticus, S. sciuri subspecies lentus, S. sciuri subspecies sciuri, S. simulans, S. warneri and S. xylosus, the remaining ones may represent the nuclei of additional centres of variation. The numerical data also cast doubts upon the reliability of some of the tests recommended for the identification of coagulase-negative staphylococci.

Computers↗

PubMed1990

[Elastolytic activity of staphylococci isolated from human oral cavity].

Elastolytic activity of 292 strains of staphylococci isolated from saliva samples obtained from children and adults was examined. It was found that 41% of coagulase-positive and 57.1% of coagulase-negative staphylococci were able to produce elastase. The difference in production frequency in relation to the ability to produce coagulase was statistically significant (p less than 0.01). Among coagulase-negative strains in addition to S. epidermidis, S. hominis, S. saprophyticus, S. haemolyticus, S. simulans, S. capitis, S. warneri and several unidentified strains were able to produce elastase.

Adult↗

PubMed1985

Expression of human choriogonadotropin-like material in coagulase-negative Staphylococcus species.

We identified 101 coagulase-negative Staphylococcus strains obtained from different laboratories, the American Type Culture Collection, and our collection, isolated from 23 patients with overt cancer and 34 normal individuals through Kloos and Schleifer conventional methods and the Staph-Ident staphylococcal system (Analytab Products, Plainview, N.Y.). In 40 strains, identity was further verified by DNA-DNA hybridization techniques. Identification revealed 39 S. epidermidis, 22 S. hominis, 8 S. haemolyticus, 9 S. capitis, 5 S. warneri, 5 S. cohnii, 8 S. saprophyticus, and 5 S. xylosus strains, all resident species found in humans. All bacteria were tested for the expression of human choriogonadotropin (hCG)-like material by the indirect fluorescein and peroxidase immunocytochemical labeling techniques by using specific antisera to the whole hormone, to its alpha and beta subunits, to the hCG beta COOH-terminal peptide, and to a monoclonal antibody to the hCG beta. The results demonstrated that the isolates from cancer patients were not unique bacteria, as has been postulated by others; the expression of immunoreactive hCG-like material is a strain, not a species, characteristic; not every bacterial strain isolated from a cancer patient is able to express the material; hCG-producing bacteria do not necessarily indicate the presence of active disease; 20% of the strains that we studied revealed a clonal variation of the expression of hCG-like material or its subunits or both as well as a variable expression of a single hCG epitope, an observation similar to that described for malignant cells; and a specific antiserum to the whole hormone with a high affinity and high sensitivity for immunocytochemistry can be a reliable reagent for screening purposes.

Animals↗

PubMed1986

[Sensitivity of 858 strains of staphylococci to 27 antibiotics].

Susceptibility to 27 antimicrobial agents of 858 strains of staphylococci was determined. Tested strains belonged to the following species: S. epidermidis, S. saprophyticus, S. haemolyticus, S. hominis, S. simulans, S. warneri, S. cohnii, S. xylosus and S. intermedius. The antibiotics were: penicillin G, amoxycillin, augmentin, oxacillin, streptomycin, kanamycin, tobramycin, dibekacin, amikacin, gentamicin, sisomycin, netilmicin, doxycycline, minocycline, chloramphenicol, erythromycin, josamycin, clindamycin, pristinamycin, rifampin, fusidic acid, fosfomycin, trimethoprim, sulfamethoxazole, cotrimoxazole, and vancomycin. The ATB system was used, with the criteria for categorization recommended by the Antibiotic Sensitivity Testing Committee. Penicillin-resistance, that was found in all species, was high for hospital-acquired strains (67 to 75%) but also for some other strains (32% for S. simulans). Oxacillin-resistance varied across species (0% for the least prevalent hospital strains, 6% for S. epidermidis and 28% for S. haemolyticus). All strains were susceptible to vancomycin. For some drugs, resistance was a characteristic of the species: resistance to fosfomycin was often found for S. saprophyticus, S. haemolyticus, S. warneri, S. cohnii, and S. capitis; resistance to trimethoprim was common for S. simulans, and S. haemolyticus. S. haemolyticus was the most resistant species, a fact that justifies routine identification of this pathogen in clinical specimens.

Anti-Bacterial Agents↗

PubMed1995

The role of extracellular polysaccharide substance produced by Staphylococcus epidermidis in miliaria.

BACKGROUND: Previous studies have indicated that cutaneous bacteria, particularly coagulase-negative staphylococci, play a role in the pathogenesis of miliaria. An accumulation of periodic acid-Schiff (PAS)-positive material has been described as blocking the sweat duct in miliaria. Furthermore, a PAS-positive extracellular polysaccharide substance (EPS) has been identified as a product of some strains of Staphylococcus epidermidis. OBJECTIVE: We evaluated the relative ability of various species of coagulase-negative staphylococci to induce miliaria with particular reference to the potential role of EPS. METHODS: We inoculated various strains of coagulase-negative staphylococci on the volar forearms of subjects under an occlusive dressing coupled with thermal stimulation. Ability to induce miliaria as well as microbiologic, histologic, and immunostaining features were evaluated. RESULTS: Miliaria was induced only with strains of S. epidermidis; other species including S. haemolyticus, S. hominis, S. cohnii, S. saprophyticus, and S. simulans were not capable of inducing miliaria. Moreover, only S. epidermidis strains capable of producing EPS were capable of inducing miliaria. CONCLUSION: Our data indicate that EPS is the PAS-positive material that obstructs the delivery of sweat to the skin surface in miliaria and therefore demonstrate that the EPS produced by S. epidermidis plays a central role in the pathogenesis of miliaria. Furthermore, in a survey of staphylococcal flora isolated from 68 subjects, EPS-producing strains were found to be common.

Adolescent↗

PubMedDate not supplied

[Bacterial causes of meningitis in newborns].

INTRODUCTION: Bacterial meningitis jeopardizes the life of affected newborns and in survived children often leaves permanent sequels. The sooner the diagnosis is established and the therapy is started, the more a prosperous outcome can be expected. When the indication is established, lumbar punction should be performed. On the basis of the results of cytological and biochemical analyses of the cerebrospinal fluid (CSF) that point to bacterial meningitis, the initial therapy should begin even before the results of bacteriological analyses. It is important to know which causes are to be expected in order to make an adequate choice of antibiotics for initial therapy. The AIM of this study is to identify the causes of meningitis, frequency of their occurrings and mortality-rate in the affected newborns. PATIENTS AND METHODS: A prospective study was carried out in the Paediatric Department of the Institute from January 1, 1978 to December 31, 2000. Patients originated from all parts of Yugoslavia. After the establishing of indication, lumbar punction was performed. CSF was sent to cytological, biochemical and bacteriological analyses. Diagnosis of meningitis was established when at least two criteria of four were fulfilled: 1. isolation of the cause by CSF culture; 2. elevation of CSF leukocyte count more than 20 with predominance of polymorphonuclear leukocytes; 3. hypoglucorrhachia (glycaemia less than 40 mg percent or less than 50 percent of glycaemia); 4. identification of bacteria by the Gram stain of CSF sediment. In 173 newborns the cause of bacterial meningitis was confirmed. RESULTS AND DISCUSSION: Causes of meningitis were as follows: E. coli in 46 newborns (N) (26.5%), Streptococcus B haemolyticus group B in 35 N (20.2%), K. pneumoniae in 27 N (15.6%), K. oxytoca in 3 N (1.7%), Proteus spp in 14 N (8%), Salmonella spp in 12 N, Pseudomonas spp in 9 N, Streptococcus pneumoniae in 9 N, Acinetobacter calcoaceticus in 4 N, Enterobacter spp in 3 N, L. monocytogenes and Serratia marcescens and Staphylococcus aureus in 2 N each, and in one N. meningitidis, Streptococcus group D, Citrobacter, Morganella morganii and Alkaligenes xilosoxidans. Over the period 1978-1987, the most frequent causes were: E. coli (28.2%), SBHB (26.8%) and Klebsiella spp (11.3%). Over the period 1991-2000, order and frequency of causes had been changed: Klebsiella spp (26.8%), E. coli (19.2%), SBHB (14.1%), etc. In addition, new causes appeared, namely: Morganella morganii, Citrobacter, K. oxitoca and Alkaligenes xylosoxidans (Table 2). Of a total of 173 patients, 52 (30.1%) died: of 124 children with meningitis caused by gram-negative bacteria, 39 (31.4%) died, and of 49 children with gram-positive bacteria, 13 (26.5%) died (Table 1). Comparing the first and the last decade, mortality decreased by only 0.2% (Table 2). The explanation might be that the patients came to the Institute too late, and after manifestation of resistant and multiresistant causes that obscured the appropriate selection of antibiotics for initial therapy. The precious time between the onset of the disease and start of the therapy was lost in this way. Newborns with bacterial meningitis should be treated only in health institutions where the intensive care units for newborns exist. CONCLUSION: The most frequent causes of meningitis are the following: E. coli, SBHB and Klebsiella pn. Frequency of causes of meningitis changed with time. New uncommon causes have appeared. The mortality-rate remained very high.

Bacteria↗

PubMed1986

Slime production by bovine milk Staphylococcus aureus and identification of coagulase-negative staphylococcal isolates.

Staphylococcus aureus isolates from bovine milk were assessed for capsule or slime production. When pure S. aureus cultures in milk were inoculated directly into serum-soft agar constituted with a modified staphylococcus 110 medium, 100% of the isolates grew with diffuse colony morphology. Diffuse colony morphology was rapidly lost on subculture and was more rapidly lost in brain heart infusion-serum-soft agar. No evidence was seen for encapsulation in India ink preparations or by the clumping factor test. It was concluded that freshly isolated S. aureus strains produce slime, not true capsules. During examination of the 84 milk samples that grew staphylococci in addition to S. aureus (27.4%), a significant number of coagulase-negative staphylococcal species were encountered and identified by conventional tests as S. simulans (41.7%), S. xylosus (11.9%), S. epidermidis (3.6%), S. saprophyticus (3.6%), S. hyicus (2.9%), S. cohnii (1.2%), S. haemolyticus (1.2%), and S. warneri (1.2%). Five isolates (6.0%) were not identified. Attempts were also made to identify the isolates by the API Staph-Ident system, which gave an overall accuracy of 45.2%. The susceptibilities of the isolates to a variety of antibiotics were determined, and they appeared to be less resistant than human clinical isolates.

Animals↗

PubMed1982

Comparison of antimicrobial susceptibility patterns among coagulase-negative staphylococci.

Coagulase-negative staphylococci, identified as S. epidermidis, S. saprophyticus, S. haemolyticus, S. hominis, and S. warneri, were tested for susceptibility to a number of antimicrobial agents by disk agar diffusion and broth microdilution methods, S. warneri and S. saprophyticus were found to be the most susceptible, and S. haemolyticus and S. epidermidis were found to be the least susceptible. Differences in antimicrobial susceptibility patterns are discussed, along with their epidemiological and therapeutic implications.

Anti-Bacterial Agents↗

PubMed1982

Species identification of coagulase-negative staphylococcal isolates from blood cultures.

Coagulase-negative staphylococci generally are not fully identified, are called Staphylococcus epidermidis, and are considered contaminants when isolated from blood cultures. In a cancer hospital during 6 months, 46 patients had multiple blood cultures (mean, 3.1) which yielded coagulase-negative staphylococci. Species identification of these showed that 10 of the 46 (22%) were not S. epidermidis. Similarly, 96 coagulase-negative staphylococci isolated from only one of multiple blood cultures from patients and thought to be skin contaminants were identified. Of 96 of the staphylococci, 14 (16%) of the latter group were not S. epidermidis. Species found included S. haemolyticus, S. hominis, S. warneri, S. simulans, and S. xylosus. Eight isolates of these species were methicillin resistant, and all eight were mannitol fermenters. The results suggest that these species invasively infect cancer patients with the same frequency at which the species colonize. No one species was identified as being more pathogenic than the others. Routine species identification of coagulase-negative staphylococci from blood cultures of cancer patients contributed little to management except to occasionally distinguish multiple-episode culture contamination by different species from sustained bacteremia with the same species.

Adult↗

PubMed1993

[In vitro activity of glycopeptides on 114 coagulase-negative staphylococci: problems with the teicoplanin diffusion test, "alert" parameters indicating need for MIC determination].

The activity of vancomycin (Va) and teicoplanin (Tc) against 114 coagulase-negative staphylococci (CNS) strains was evaluated by disk-diffusion and agar dilution minimal inhibitory concentration (MIC) determination. Results were analysed by species and methicillin-resistance (MR) status. MICs for Va were in the susceptible range (< 4 mg/l) for all strains, with inhibition zone diameters of 17 mm or more in every case. MICs for teicoplanin were 8 or 16 mg/l for 19 CNS strains (including 18 with MR) of which 14 yielded an inhibition zone diameter of 17 mm or more (false susceptibility). Parameters which should lead to MIC determination for Tc regardless of disk diffusion findings include the species (S. haemolyticus), methicillin resistance, Tc zone diameter, and an at least 3 mm difference between the Va and Tc zone diameters.

Dose-Response Relationship, Drug↗