Rhinopharynx irrigations and mouthwash with dissolved mupirocin in treatment of MRSA throat colonization - proof-of-concept study.

BACKGROUND: To prevent transmission of, and infection with, meticillin-resistant Staphylococcus aureus (MRSA), eradication treatment of colonized individuals is recommended. Throat colonization is a well-known risk factor for eradication failure. Staphylococcus aureus throat colonization is associated with colonization of the rhinopharynx, but in the currently recommended Danish MRSA eradication strategies, rhinopharynx colonization is not directly targeted. Rhinopharynx colonization could therefore be an important risk factor for prolonged MRSA throat carriage. AIM: To determine whether irrigation and wash of the rhinopharynx and mouth with dissolved mupirocin is a feasible and potentially efficacious supplementary strategy against treatment-resistant MRSA throat carriage. METHODS: The patient study was an open, non-blinded, trial including 20 treatment-resistant MRSA throat carriers. In the study, the patients received a supplementary treatment besides the standard treatment according to the Danish MRSA eradication strategy. The supplementary treatment consisted of rhinopharyngeal irrigation and mouth-gurgling twice a day for 14 days with a mupirocin ointment (22 g 2% ointment per litre of isotonic sterile saline solution) in a 37°C solution. FINDINGS: Eighteen patients (90%) complied with the treatment protocol and none ex-perienced any major adverse events. Out of the 18 patients who finished the study per protocol, 15 (83%) and seven (39%) patients had negative MRSA sampling results one and six months after end of treatment, respectively. CONCLUSION: This study demonstrates the feasibility and clinical potential of also targeting the rhinopharynx and oropharynx in non-systemic throat MRSA eradication strategies.

The association between pre-operative sepsis and 30-day mortality in hip fracture patients-A cohort study.

BACKGROUND: Post-operative sepsis considerably increases mortality, but the extent of pre-operative sepsis in hip fracture patients and its consequences are sparsely elucidated. The aim of this study was to assess the association between pre-operative sepsis and 30-day mortality after hip fracture surgery. METHODS: We conducted a retrospective analysis of data collected among 1894 patients who underwent hip fracture surgery in the Capital Region of Denmark in 2014 (NCT03201679). Data on vital signs, cultures and laboratory data were obtained. Sepsis was defined as a positive culture of any kind and presence of systemic inflammatory response syndrome within 24 hours and was assessed within 72 hours before surgery and 30 days post-operatively. Primary outcome was 30-day mortality. Secondary outcomes included length of hospital stay and admission to intensive care unit. RESULTS: A total of 144 (7.6%) of the hip fracture patients met the criteria for pre-operative sepsis. The 30-day mortality was 13.9% in patients with pre-operative sepsis as compared to 9.0% in those without (OR 1.69, 95% CI [1.00; 2.85], P = .08). Patients with pre-operative sepsis had longer hospital stays (median 10 days vs 9 days, mean difference 2.1 [SD 9.4] days, P = .03), and higher frequency of ICU admission (11.1% vs 2.7%, OR 4.15, 95% CI [2.19; 7.87], P < .0001). CONCLUSION: Pre-operative sepsis in hip fracture patients was associated with an increased length of hospital stay and tended to increase mortality. Pre-operative sepsis in hip fracture patients merits more intensive surveillance and increased attention to timely treatment.

Screening for vancomycin-resistant enterococci with Xpert® vanA/vanB: diagnostic accuracy and impact on infection control decision making.

Vancomycin-resistant enterococci (VRE) are increasingly important nosocomial pathogens and screening for colonization status is a mainstay in infection control. We implemented PCR-based screening during vanA-positive Enterococcus faecium outbreaks in four university hospitals in Copenhagen, Denmark. Xpert®vanA/vanB was performed directly on rectal swabs and the vanA PCR result was used to guide infection control measures. Concurrently, all samples were selectively cultured including an overnight enrichment step. Diagnostic accuracy was calculated as well as turnaround time and the impact of the earlier available PCR results on infection control decision making. In all, 1110 samples were analysed. The vanA PCR positivity rate was 13.8% and culture positivity rate was 15.2%. The diagnostic accuracy of the vanA part of the assay was high with a sensitivity of 87.1%, a specificity of 99.7%, and positive and negative predictive values of 98.0% and 97.7%, respectively. The vanB PCR had a considerably lower specificity of 77.6% and a positive predictive value of 0.4%. In 1067 (96.1%) samples, PCR results were reported within 1 day, whereas median culture turnaround time was 3 days. The saving of time to available results corresponded to 141 saved isolation days and 292 saved transmission risk days. False-negative or false-positive PCR results led to six additional transmission risk days and 13 additional isolation days, respectively. The vanA PCR had high diagnostic accuracy and the prompt availability of results gave a considerable benefit for infection control decision making.

Monitoring meticillin resistant Staphylococcus aureus and its spread in Copenhagen, Denmark, 2013, through routine whole genome sequencing.

Typing of meticillin resistant Staphylococcus aureus (MRSA) by whole genome sequencing (WGS) is performed routinely in Copenhagen since January 2013. We describe the relatedness, based on WGS data and epidemiological data, of 341 MRSA isolates. These comprised all MRSA (n = 300) identified in Copenhagen in the first five months of 2013. Moreover, because MRSA of staphylococcal protein A (spa)-type 304 (t304), sequence type (ST) 6 had been associated with a continuous neonatal ward outbreak in Copenhagen starting in 2011, 41 t304 isolates collected in the city between 2010 and 2012 were also included. Isolates from 2013 found to be of t304, ST6 (n=14) were compared to the 41 earlier isolates. In the study, isolates of clonal complex (CC) 22 were examined in detail, as this CC has been shown to include the hospital-acquired epidemic MRSA (EMRSA-15) clone. Finally, all MRSA ST80 were also further analysed, as representatives of an important community-acquired MRSA in Europe. Overall the analysis identified 85 spa-types and 35 STs from 17 CCs. WGS confirmed the relatedness of epidemiologically linked t304 neonatal outbreak isolates. Several non-outbreak related patients had isolates closely related to the neonatal isolates suggesting unrecognised community chains of transmission and insufficient epidemiological data. Only four CC22 isolates were related to EMRSA-15. No community spread was observed among the 13 ST80 isolates. WGS successfully replaced conventional typing and added information to epidemiological surveillance. Creation of a MRSA database allows clustering of isolates based on single nucleotide polymorphism (SNP) calling and has improved our understanding of MRSA transmission.

Evaluating antibiotic stewardship programs in patients with bacteremia using administrative data: a cohort study.

When introducing new antibiotic guidelines for empirical treatment of bacteremia, it is imperative to evaluate the performance of the new guideline. We examined the utility of administrative data to evaluate the effect of new antibiotic guidelines and the prognostic impact of appropriate empirical treatment. We categorized 2,008 adult patients diagnosed with bacteremia between 2010 and 2012 according to whether they received cephalosporins or fluoroquinolones (old regimen) or not (new regimen). We used administrative data to extract individual level data on mortality, readmission, and appropriateness of treatment, and computed adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for 30-day mortality and post-discharge readmission by regimen and appropriateness of treatment. In total, 945 (47.1%) were treated by the old regimen and 1,063 (52.9%) by the new. The median length of stay (8 days) did not differ by regimen and neither did the proportion of those receiving appropriate empirical treatment (84.1% vs. 85.5%). However, fewer patients with the new regimen were admitted to the intensive care unit (ICU; 3.8% vs. 12.0%) and they had lower 30-day mortality (16.4% vs. 23.4%). The adjusted 30-day mortality HR for appropriate versus inappropriate treatment was 0.79 (95% CI 0.62-1.01) and 0.83 (95% CI 0.66-1.05) for the new versus the old regimen. The HR for 30-day readmission for appropriate versus inappropriate treatment was 0.91 (95% CI 0.73-1.13) and 1.05 (95% CI 0.87-1.25) for the new versus the old regimen. This study demonstrates that administrative data can be useful for evaluating the effect and quality of new bacteremia treatment guidelines.

Detection of candidaemia in patients with and without underlying haematological disease.

Diagnosing candidaemia remains difficult despite the development of new diagnostics. We report a direct comparison of three different blood-culture systems and four indirect tests. One hundred and fourteen episodes either with haematological disease and fever despite antibacterials, or with documented invasive candidiasis, were enrolled prospectively. Clinical, para-clinical information and surveillance cultures were obtained. Blood culture was performed using conventional blood-culture bottles, mycosis bottles, and the Isolator 10 lysis centrifugation system. Serum D-arabinitol/L-arabinitol (DA/LA) ratios were determined by gas chromatography mass spectrometry. Antigen, mannan-antigen (Ag) and anti-mannan antibody (Ab) were detected by CandTec, Platelia Candida Ag ELISA and Candida AB/AC/AK kits, respectively. Episodes were classified as proven (n = 24), probable (n = 14), possible (n = 52) or unlikely (n = 24) invasive candidiasis. Candidaemia involved C. albicans (17), C. albicans + C. glabrata (3), C. tropicalis (1) and yeast (1). Mycosis bottles yielded two additional positives and the conventional blood culture yielded one positive not identified by other blood-culture methods. Considering proven and unlikely episodes, respectively, sensitivity and specificity were as follows: mannan-Ag and/or anti-mannan Ab: 83.3%, 78.3%; DA/LA ratio: 41.7%, 86.4%; and CandTec Candida Ag: 66.6%, 70.8%. Lowering the cut-off values to mannan-Ag 0.10 ng/mL and anti-mannan Ab 4 AU/mL, the values were: 100%, 73.9%. Applying the DA/LA ratio to only patients with haematological neutropenia the values were: 75%, 90.5%. Fungal blood culture allowed slightly improved detection of candidaemia. The best indirect test performance was obtained from combined mannan-Ag and anti-mannan Ab detection, especially with lower cut-offs. DA/LA ratio appears to be useful in the context of haematological neutropenia.

Staphylococcus aureus and hand eczema severity.

BACKGROUND: The role of bacterial infections in hand eczema (HE) remains to be assessed. OBJECTIVES: To determine the prevalence of Staphylococcus aureus in patients with HE compared with controls, and to relate presence of S. aureus, subtypes and toxin production to severity of HE. METHODS: Bacterial swabs were taken at three different visits from the hand and nose in 50 patients with HE and 50 controls. Staphylococcus aureus was subtyped by spa typing and assigned to clonal complexes (CCs), and isolates were tested for exotoxin-producing S. aureus strains. The Hand Eczema Severity Index was used for severity assessment. RESULTS: Staphylococcus aureus was found on the hands in 24 patients with HE and four controls (P < 0.001), and presence of S. aureus was found to be related to increased severity of the eczema (P < 0.001). Patients carried identical S. aureus types on the hands and in the nose in all cases, and between visits in 90% of cases. Ten different CC types were identified, no association with severity was found, and toxin-producing strains were not found more frequently in patients with HE than in controls. CONCLUSIONS: Staphylococcus aureus was present on hands in almost half of all patients with HE, and was significantly related to severity of the disease. This association indicates that S. aureus could be an important cofactor for persistence of HE.

Neonatal colonization with Staphylococcus aureus is not associated with development of atopic dermatitis.

BACKGROUND: Staphylococcus aureus in atopic skin has been associated with exacerbation of eczema. Objectives To investigate a possible association between neonatal colonization with S. aureus and the risk of atopic dermatitis (AD) during the first 3 years of life. MATERIALS AND METHODS: The study participants were 356 children born of mothers with asthma from the Copenhagen Prospective Study on Asthma in Childhood. Swabs from the vestibulum nasi and the perineum were cultured at 1 month and 1 year, from acute eczema, and from parents (vestibulum nasi and pharynx). AD development and severity were monitored prospectively. RESULTS: Of the neonates, 5.3% had positive swabs for S. aureus cultured from the vestibulum nasi (51.3%) and/or the perineum (11.3%). Forty-two per cent developed AD, but without association between colonization with S. aureus at 1 month of age and risk of developing AD at 3 years of age. There was a 70% concordance for S. aureus carriage between neonates and parents. At 1 year of age 11.3% children had swabs positive for S. aureus. Fourteen per cent of children tested at the 1-year visit developed AD after the visit but before 3 years of age, but again, there was no association between colonization with S. aureus and the risk of AD. In children seen at acute visits the severity of AD measured by scoring of atopic dermatitis (SCORAD) was significantly higher in children with a positive culture for S. aureus in lesions. CONCLUSIONS: Colonization with S. aureus at 1 month of age is not associated with an increased risk of developing AD during the first 3 years of life.

Autologous transfusion of shed mediastinal blood after coronary artery bypass grafting and bacterial contamination.

BACKGROUND: Autologous transfusion of shed mediastinal blood is often used after coronary artery bypass grafting (CABG). Shed blood has in a few studies been cultured during the first postoperative hours. However, autologous transfusion might in some cases be continued for several hours and no study has yet examined the bacterial contamination of shed blood later than 6 hours postoperatively. METHODS: Seventy-five patients undergoing electively performed CABG were included. Cultures of shed blood were taken at initiation of the autologous transfusion and the following morning. Infection variables were measured preoperatively and postoperatively. Infectious complications during the first postoperative week were registered. RESULTS: The frequency of patients with bacterial growth in the first culture was 0.22 (95% confidence interval: 0.12 to 0.31) compared with 0.04 (95% confidence interval: -0.044 to 0.087) in the second culture (p < 0.002). We found no significant difference in infection variables between patients with or without bacterial growth in the cultures. No patients suffered from early postoperative infectious complications. CONCLUSIONS: There is no further contamination of the shed blood during the period between initiating the autologous transfusion and the following morning.

Gentamicin dosing in critically ill patients.

Gentamicin is used worldwide in the treatment of serious infections in critically ill patients. The therapeutic efficacy of gentamicin is correlated to the peak serum concentration and the adverse effects to the trough concentrations. Information concerning the pharmacodynamics in critically ill patients is scarce, but pharmacokinetic data are available. A once-daily dosage regimen has replaced multiple dosing of gentamicin in most intensive care units. No studies evaluating the superiority of either of these dosage recommendations in critically ill patients have ever been conducted. Based on 8 meta-analyses performed addressing this issue on a wide range of patients and theoretical considerations, we consider a once-daily dosage regimen feasible in critically ill patients. In septic patients the volume of distribution is significantly increased compared to normal patients, implying that the initial dose should be increased in this patient population. Additionally a general trend towards using higher loading doses (5-7 mg/kg) has been observed in USA, and the appropriateness of this dosing strategy is based on a large descriptive American study. We recommend that the initial dosage of gentamicin in critically ill hyperdynamic septic patients should be 7 mg/kg. Optimal and appropriate monitoring of the treatment with gentamicin in the critically ill patient is still an issue for further investigation. The treatment period with gentamicin should be short (3-5 days), bearing the pharmacological properties of aminoglycosides (small volume of distribution and poor tissue penetration) in mind. In patients with reduced renal function the initial dose of gentamicin should also be increased and maintenance dose reduced preferentially by prolonging the dosing intervals. However, the use of aminoglycosides in a high dose regimen in oliguric or anuric patients or patients who present with a rapidly decreasing renal function needs further consideration.

Phenotypic characteristics of coagulase-negative staphylococci: typing and antibiotic susceptibility.

The present thesis deals with various aspects of handling coagulase-negative staphylococci (CoNS) in the local clinical microbiology laboratory. CoNS are normal inhabitants of the skin and mucus membranes and are increasingly being recognised as opportunistic pathogens causing infection in the immunocompromised host, in particular patients with indwelling plastic devices. In particular the finding of CoNS in specimens which should normally be sterile, such as blood cultures, is of interest. The isolation of the same strain of an opportunistic pathogen, such as CoNS, enhance the likelihood of the bacteria causing infection. Multiple antibiotic resistance, in particular methicillin resistance, is frequent among CoNS hospital-strains on a global scale. beta-lactam antibiotics are the most valuable antibiotics for the treatment of infection with susceptible CoNS. A reliable method for the detection of methicillin resistance, and hereby resistance to all beta-lactam antibiotics, is therefore important. A simple identification method, Minibact-S, has been developed. Minibact-S can identify the CoNS species, which are the most frequently occurring in human specimens. Furthermore, Minibact-S can subtype Staphylococcus epidermidis. Another phenotypic typing method, lectin typing, has been developed for typing S. epidermidis. Lectin typing involves the binding of various biotinylated lectins to the surface of whole immobilised cells of CoNS. Lectins are proteins or glycoproteins which bind specifically to various glycans. When the lectins: Wheat Germ Agglutinin (WGA), Soy Bean Agglutinin (SBA), Concanavalin A (ConA), and Lens Culinaris Agglutinin (LCA) were included, typing of S. epidermidis gave a discriminatory power of the same magnitude as found for DNA-plasmid profile analysis. Lectin typing could be used as a supplementary typing method for S. epidermidis in the local clinical microbiology laboratory, since the method is simple, reproducible and does not require expensive and sophisticated equipment. Various typing schemes for S. epidermidis, i.e. typing which involves several typing methods, have been tested: lectin typing, DNA-plasmid profile analysis, antibiotic susceptibility testing, phage typing, and slime production lectin typing, antibiotic susceptibility testing, biotyping (Minibact-S), phage typing antibiotic susceptibility testing and biotyping (Minibact-S) For use as a "first line" typing scheme in the local clinical microbiology laboratory, the typing of S. epidermidis by combined antibiotic susceptibility testing and biotyping is easy to handle. Antibiotic susceptibility testing should include antibiotics from several groups of antibiotics having different resistance mechanisms. Antibiotic susceptibility among Danish CoNS-strains from blood cultures was studied. A major diversity in species distribution and antibiotic susceptibility was found between different Danish regions, for example methicillin resistant CoNS accounted for 40% in Copenhagen County and only for 21% in Northern Jutland County. Diversity in species distribution was also marked; an example of this is that 73% of the strains from Copenhagen Municipality were identified as S. epidermidis compared to only 46% in Northern Jutland County. In a study from Rigshospitalet, Copenhagen, great diversity in antibiotic susceptibility was detected between the different wards. In four wards investigated, high consumption of carbapenems, Third-generation cephalosporins, and quinolones was associated with high prevalence of methicillin resistance. Furthermore, for ciprofloxacin, ciprofloxacin-resistant CoNS-strains were practically not detected in the Neonatal Ward where ciprofloxacin is not used. In contrast to the nationwide study, glycopeptide resistance was found at Rigshospitalet: 5% of the CoNS strains were teicoplanin-resistant but all strains were vancomycin-susceptible. In both the above mentioned studies, antibiotic resistance was strongly associated with

Coagulase-negative staphylococci in a major Danish university hospital: diversity in antibiotic susceptibility between wards.

Over a one-year period, all coagulase-negative staphylococci (CoNS) from blood cultures, cerebrospinal fluids and peritoneal effluents from patients in a major Danish university hospital were investigated for susceptibility to penicillin G; methicillin; gentamicin; netilmicin; amikacin; erythromycin; clindamycin; fusidic acid; rifampicin; tetracycline; chloramphenicol; ciprofloxacin; teicoplanin; and vancomycin. Among the CoNS-isolates, 56% were resistant to methicillin, 51% to gentamicin, 28% to ciprofloxacin, and 5% to teicoplanin. Blood culture CoNS-isolates from patients with a central venous catheter (CVC) were more often resistant to various antibiotics compared to CoNS-isolates from patients without a CVC, e.g. methicillin (72% vs 21%), gentamicin (65% vs 22%) (p<0.00000001). Great diversity in antibiotic resistance between the wards was found; methicillin resistance (in most cases multiple antibiotic resistance) was in particular associated with consumption of broad-spectrum beta-lactams, quinolones, and total antibiotic consumption in a ward. Thus, the antibiotic policy of a ward is an important factor for antibiotic resistance among CoNS.

IgE-binding components of staphylococcal enterotoxins in patients with atopic dermatitis.

BACKGROUND: The exacerbation of atopic dermatitis may be associated with infection of the skin with Staphylococcus aureus (S.aureus). S. aureus isolated from the skin of patients with atopic dermatitis secretes enterotoxin A, B, and toxic shock syndrome toxin 1. This is of interest because these patients may develop specific IgE antibodies against components from staphylococci. OBJECTIVE: The objective was to demonstrate IgE-sensitization to components of Staphylococcus aureus enterotoxins A and B (purified and partially purified), toxic shock syndrome toxin 1, and the bacterial cell component lipoteichoic acid, in patients with atopic dermatitis. METHODS: Blood samples from 34 patients with atopic dermatitis and 10 controls were tested by leukocyte histamine release to the enterotoxins and lipoteichoic acid. The toxins were separated by sodium dodecylsulfate polyacrylamide gel electrophoresis and analyzed by IgE-immunoblotting with sera from the same patients. RESULTS: The majority of patients (96%) with clinical signs of skin infection produced specific IgE-antibodies to all three toxins. Nearly half of the patients produced IgE to enterotoxin A and B. Only 63% of the patients with atopic dermatitis showed cellular response judged by the release of histamine from patient basophils when challenged in vitro with the toxins. This may indicate clinically unimportant sensitization in a number of patients. The immunoblotting revealed that the major allergens of the toxins were 24 and 28 kD proteins. Partially purified toxins showed a higher frequency of leukocyte histamine release responses than purified toxin. The only obvious difference was a difference in the content of pure toxin of the two preparations. Lipoteichoic acid showed nonspecific activity. CONCLUSION: These findings suggest that staphylococcal enterotoxins may act as specific allergens and induce IgE-antibodies to enterotoxins that may exacerbate the skin inflammation in some patients with atopic dermatitis.

Evaluation of different methods for the detection of methicillin resistance in coagulase-negative staphylococci.

The efficacy of 19 agar diffusion methods for the detection of methicillin resistance among coagulase-negative staphylococci (CoNS) within 24 h was evaluated. A total of 359 CoNS isolates were tested, of which 204 were Staphylococcus epidermidis. In 164 isolates, the presence of mecA was investigated; 61 strains were mecA-positive and 103 were mecA-negative by Southern blot analysis. Based on the best agreement shown with the mecA determination (94%) among four agar dilution assays for determining methicillin MIC, an assay with Columbia agar supplemented with NaCl and incubation with a heavy bacterial inoculum of 10(5)-10(6) cfu/spot was used as the reference MIC method. The best agar diffusion results were obtained with a 1 microg oxacillin disc on Columbia agar with 4.5% NaCl supplement. With this method, 99% of S. epidermidis and 94% of non-S. epidermidis were in agreement with the MIC determination. However, Columbia (without NaCl), Mueller-Hinton and Isosensitest agars were almost as useful when a 1 microg oxacillin disc was used. The zone breakpoints for S. epidermidis were, in general, considerably larger than those for other CoNS species and, consequently, differentiation according to species is recommended. Furthermore, resistance to other antibiotics, such as gentamicin and erythromycin, makes methicillin resistance highly likely.

Excretion of ciprofloxacin in sweat and multiresistant Staphylococcus epidermidis.

BACKGROUND: Staphylococcus epidermidis develops resistance to ciprofloxacin rapidly. That this antibiotic is excreted in apocrine and eccrine sweat of healthy individuals might be the reason for the development of such resistance. We assessed whether S epidermidis isolated from the axilla and nasal flora of healthy people could develop resistance to ciprofloxacin after a 1-week course of this antibiotic. METHODS: The concentration of ciprofloxacin in sweat was measured in seven volunteers after oral administration of 750 mg ciprofloxacin twice daily for 7 days, and the development of resistance in S epidermidis from axilla and nostrils was monitored during and 2 months after the treatment. Genotyping of S epidermidis was done by restriction fragment length polymorphism. FINDINGS: The mean concentration of ciprofloxacin in sweat increased during the 7 days of treatment-from 2.2 micrograms/mL 2.5 h after the first tablet to 2.5 micrograms/mL after the fifth tablet, and 5.5 micrograms/mL after the 13th tablet. All persons harboured susceptible S epidermidis (minimal inhibitory concentration [MIC] 0.25 microgram/mL) in axilla and nostrils before treatment. Four resistant strains were detected, two intermediate-level (MIC 4-12 micrograms/mL) and two high-level (MIC > 32 micrograms/mL). Three of these strains were found in all the participants, and a ciprofloxacin-sensitive variant of one of the high-level resistant strains was also found before the start of the treatment. The high-level resistant strains were also resistant to methicillin, erythromycin, gentamicin, sulphonamide, and trimethoprim. A mean of 2.7 days after the start of the treatment, development of ciprofloxacin resistance was detected in S epidermidis from the axilla of all persons, compared with 11 days for the appearance of resistant S epidermidis in nostrils. The resistant strains persisted for an average of 37 and 39 days in axilla and nostrils, respectively, after the end of the treatment. INTERPRETATION: The rapid development of resistance to ciprofloxacin due to excretion of this drug into the sweat might be involved in the development of multiresistant S epidermidis and possibly other skin bacteria in hospitals and in communities with high use of ciprofloxacin or related drugs.

Coagulase-negative Staphylococci in Danish blood cultures: species distribution and antibiotic susceptibility.

The distribution and antibiotic susceptibility of coagulase-negative staphylococci (CoNS) isolated from blood cultures was examined in samples from hospitals covering most of Denmark. A total of 499 CoNS isolates were detected in 477 blood cultures from 340 patients and speciated as Staphylococcus epidermidis, 285; Staphylococcus hominis, 61; Staphylococcus haemolyticus, 43; Staphylococcus warneri, 12; Staphylococcus cohnii, 7; Staphylococcus saprophyticus, 4; Staphylococcus capitis, 2 and Staphylococcus lugdunensis, 1. Seventy-eight isolates could not be identified to species level and six were Micrococcus spp. In 108 (22.6%) blood culture sets, more than one CoNS strain were found, as detected by species identification, antibiogram and biotyping. Significantly more blood cultures from patients in university hospitals were drawn from central venous catheters. Comparing university and non-university hospitals, the overall antibiotic susceptibility among CoNS was only slightly different, except for methicillin and amikacin. The prevalence of methicillin-resistant strains was 35.1% in the university hospital strains vs. 25.3% in the non-university hospital strains. The overall prevalence of methicillin resistance was 32%. Great geographic variation in both species distribution and antibiotic resistance was observed. The high prevalence of S. epidermidis makes subtyping of this species important.