Effectiveness and safety of cefazolin versus cloxacillin in endocarditis due to methicillin-susceptible Staphylococcus spp.: a multicenter propensity weighted cohort study.

PURPOSE: To compare the effectiveness and safety of cefazolin versus cloxacillin for the treatment of infective endocarditis (IE) due to methicillin-sensitive Staphylococci (MSS). METHODS: Data were retrospectively collected on patients treated for a definite MSS endocarditis who received cefazolin or cloxacillin for at least 10 consecutive days in six French hospitals between January-1 2014 and December-31 2020. The primary endpoint was treatment failure defined as a composite of death within 90 days of starting antibiotherapy, or embolic event during antibiotherapy, or relapse of IE within 90 days of stopping antibiotherapy. We used Cox regression adjusted for the inverse probability of treatment weighting of receiving cefazolin. RESULTS: 192 patients were included (median age 67.8 years). IE was caused by S.aureus in 175 (91.1%) and by coagulase-negative staphylococci in 17 (8.9%). Ninety-four patients (48.9%) received cefazolin, and 98 (51%) received cloxacillin. 34 patients (34.7%) with cefazolin and 26 (27.7%) with cloxacillin met the composite primary endpoint, with no significant differences between groups (adjusted HR = 1.13, 95% CI 0.63 to 2.03). There were no significant differences in secondary efficacy endpoints or biological safety events. CONCLUSION: The effectiveness of cefazolin did not significantly differ from cloxacillin for the treatment of MSS endocarditis.

Increase in methicillin-susceptible Staphylococcus aureus bloodstream infections in Switzerland: a nationwide surveillance study (2008-2021).

PURPOSE: An increasing burden of Staphylococcus aureus bloodstream infections (BSI), despite a decrease in the percentage of methicillin-resistant S. aureus (MRSA), was described recently in other European countries. The main aim of this study was to analyse recent temporal trends of S. aureus, methicillin-susceptible S. aureus (MSSA) and MRSA BSI for Switzerland as well as the different linguistic regions within Switzerland. An additional aim was to estimate potential differences among patient-based and epidemiological risk factors. METHODS: A retrospective observational study was conducted in Switzerland over a period of 14 years (2008-2021). Trends in S. aureus, MSSA and MRSA BSI were analysed by applying linear regression models. RESULTS: Staphylococcus aureus BSI increased by + 30% from 19.7 to 25.6 cases per 100,000 inhabitants between 2008 and 2021 (P < 0.01) in Switzerland. Thereof, MSSA increased by + 37% from 17.8 to 24.4 cases per 100,000 inhabitants (P < 0.01). MRSA decreased from 1.9 to 1.2 cases per 100,000 inhabitants (P < 0.01), which was driven by decreasing incidence in the French-speaking region. MSSA BSI increased significantly (P < 0.01) in both linguistic regions. A further stratification revealed that incidence increased the most in male patients of the age group ≥ 80 years of the German-speaking region. CONCLUSION: The increasing health burden of MSSA BSI in Switzerland indicates that not only proportions of resistant microorganisms but also total BSI incidences should be monitored. In addition, data stratification revealed that the increase was mainly driven by an increasing incidence in elderly males of the German-speaking region.

MIC Discrepancies between Parenteral and Oral Anti-Staphylococcal Beta-Lactams among MSSA.

INTRODUCTION: Recent evidence has shown that oral antibiotic therapy is not inferior to IV antibiotic therapy in the treatment of complicated Staphylococcus aureus infections. Therefore, oral antibiotic therapy is now frequently prescribed in clinical practice due to cost benefit, ease of administration, decreased complication rate, and lack of need for IV access. In vitro susceptibility testing for ß-lactam oral antibiotics is not routinely performed as the guidelines provided by the Clinical and Laboratory Standards Institute (CLSI) recommend using oxacillin and cefoxitin as surrogate markers. Hence, oral antibiotic susceptibilities for cephalexin and dicloxacillin are not reported and implied based on oxacillin and cefoxitin. The objective of the current study was to determine whether susceptibilities among S. aureus isolates are predictable when comparing commonly used IV and oral beta-lactams. METHODS: Cefazolin, cephalexin, dicloxacillin, and oxacillin broth microdilution minimum inhibitory concentrations (MICs) were determined for 100 clinical isolates of methicillin-sensitive S. aureus by broth microdilution following CLSI guidelines. RESULTS: Among these isolates, median MICs for cephalexin were eight-fold higher than cefazolin MICs and median MICs for dicloxacillin were four-fold less than oxacillin MICs. Ten percent of more strains studied had a major or very major error in its susceptibility reporting when cephalexin was compared to its surrogate marker oxacillin. DISCUSSIONS/CONCLUSIONS: The variations in MICs observed compounded with the dosing and pharmacokinetic differences of oral versus IV ß-lactam suggests that establishing breakpoints for oral ß-lactam antibiotics is necessary to ensure adequate therapy is selected for the treatment of complex S. aureus infections.

Streptococcal and Staphylococcus aureus prosthetic joint infections: are they really different?

BACKGROUND: Staphylococci and streptococci are the most frequent pathogens isolated from prosthetic joint infections (PJIs). The aim of this study was to analyze the outcome of streptococcal and methicillin-susceptible Staphylococcus aureus (MSSA) PJIs. METHODS: All monomicrobial streptococcal and MSSA PJIs managed in a French Referral Center (2010-2017) were sampled from the prospective PJIs cohort study. The primary outcome of interest was the cumulative reinfection-free survival at a 2-year follow-up. RESULTS: Two hundred and nine patients with 91 streptococcal and 132 staphylococcal infections were analyzed. Patients with streptococcal PJI were older, and infection was more frequently hematogenous. Reinfection-free survival rates at 2-years after all treatment strategies were higher for patients with streptococcal PJI (91% vs 81%; P = .012), but differed according to the strategy. After exchange arthroplasty, no outcome differences were observed (89% vs 93%; P = .878); after debridement, antibiotics and implant retention (DAIR), the reinfection-free survival rate was higher for patients with streptococcal PJI (87% vs 60%; P = .062). For patients managed with prolonged suppressive antibiotic therapy (SAT) alone, those with streptococcal PJIs had a 100% infection-free survival (100% vs 31%; P < .0001). CONCLUSIONS: Reinfection-free survival after DAIR and SAT was better for patients with streptococcal than those with MSSA PJIs. No difference was observed after prosthesis exchange.

Opportunities to Improve Antibiotic Prescribing in Outpatient Hemodialysis Facilities: A Report From the American Society of Nephrology and Centers for Disease Control and Prevention Antibiotic Stewardship White Paper Writing Group.

Antibiotic use is necessary in the outpatient hemodialysis setting because patients receiving hemodialysis are at increased risk for infections and sepsis. However, inappropriate antibiotic use can lead to adverse drug events, including adverse drug reactions and infections with Clostridioides difficile and antibiotic-resistant bacteria. Optimizing antibiotic use can decrease adverse events and improve infection cure rates and patient outcomes. The American Society of Nephrology and the US Centers for Disease Control and Prevention created the Antibiotic Stewardship in Hemodialysis White Paper Writing Group, comprising experts in antibiotic stewardship, infectious diseases, nephrology, and public health, to highlight strategies that can improve antibiotic prescribing for patients receiving maintenance hemodialysis. Based on existing evidence and the unique patient and clinical setting characteristics, the following strategies for improving antibiotic use are reviewed: expanding infection and sepsis prevention activities, standardizing blood culture collection processes, treating methicillin-susceptible Staphylococcus aureus infections with ß-lactams, optimizing communication between nurses and prescribing providers, and improving data sharing across transitions of care. Collaboration among the Centers for Disease Control and Prevention; American Society of Nephrology; other professional societies such as infectious diseases, hospital medicine, and vascular surgery societies; and dialysis provider organizations can improve antibiotic use and the quality of care for patients receiving maintenance hemodialysis.

Antistaphylococcal penicillins vs. cefazolin in the treatment of methicillin-susceptible Staphylococcus aureus infective endocarditis: a quasi-experimental monocentre study.

Whether cefazolin is as effective and safer than antistaphylococcal penicillins (ASPs) for the treatment of methicillin-susceptible Staphylococcus aureus (MSSA) infective endocarditis (IE) is still debated in the absence of a randomized controlled trial. In this quasi-experimental study, we aimed to assess the effectiveness and safety of these two treatments in MSSA-IE, using the ASPs nationwide shortage in April 2016 as a unique opportunity to overcome the indication bias associated with observational studies. In this single-centre study, we compared patients with Duke-Li definite MSSA-IE treated with ASPs from January 2015 to March 2016 versus those treated with cefazolin from April 2016 to December 2018, when ASPs were not available. Effectiveness outcome was 90-day all-cause mortality. Safety outcomes included significant decrease in GFR and significant increase in serum liver enzymes. Logrank test was used to compare survival rates. Of 73 patients with MSSA-IE, 35 and 38 were treated with ASPs and cefazolin, respectively. Baseline patients' characteristics (demography, native or prosthetic valve IE, clinical characteristics, cardiac and septic complications) were similar between groups. Ninety-day all-cause mortality was 28.6% and 21.1%, in patients treated with ASPs and cefazolin, respectively (logrank p = 0.5727). There was no difference between groups for incident renal or liver toxicity events: acute kidney injury 45.7% vs. 44.7% (p = 0.933), increased ALT 5.7% vs. 13.2% (p = 0.432), bilirubin increase 5.7% vs. 10.5% (p = 0.676), in ASPs vs. cefazolin groups, respectively. In this quasi-experimental, effectiveness and safety did not statistically differ between ASPs and cefazolin for MSSA-IE treatment.

Comparative Proteomic Profiling of Methicillin-Susceptible and Resistant Staphylococcus aureus.

Staphylococcus aureus is a highly successful human pathogen responsible for a wide range of infections. This study provides insights into the virulence, pathogenicity, and antimicrobial resistance determinants of methicillin-susceptible and methicillin-resistant S. aureus (MSSA; MRSA) recovered from non-healthcare environments. Three environmental MSSA and three environmental MRSA are selected for proteomic profiling using isobaric tag for relative and absolute quantitation tandem mass spectrometry (iTRAQ MS/MS). Gene Ontology annotation and Kyoto Encyclopedia of Genes and Genomes pathway annotation are applied to interpret the functions of the proteins detected. 792 proteins are identified in MSSA and MRSA. Comparative analysis of MRSA and MSSA reveals that 8 of out 792 proteins are upregulated and 156 are downregulated. Proteins that have differences in abundance are predominantly involved in catalytic and binding activity. Among 164 differently abundant proteins, 29 are involved in pathogenesis, antimicrobial resistance, stress response, mismatch repair, and cell wall synthesis. Twenty-two proteins associated with pathogenicity including SPA, SBI, CLFA, and DLT are upregulated in MRSA. Moreover, the upregulated pathogenic protein ENTC2 in MSSA is determined to be a super antigen, potentially capable of triggering toxic shock syndrome in the host. Enhanced pathogenicity, antimicrobial resistance, and stress response are observed in MRSA compared to MSSA.

Synergistic Activity of Exebacase (CF-301) in Addition to Daptomycin against Staphylococcus aureus in a Neutropenic Murine Thigh Infection Model.

We evaluated the efficacy of escalating doses of exebacase administered with subtherapeutic daptomycin exposures against 8 Staphylococcus aureus isolates in a neutropenic murine thigh infection model. Daptomycin alone resulted in mean growth of 0.39 ± 1.19 log10 CFU/thigh. When administered with daptomycin, exebacase resulted in a mean log10 CFU/thigh reduction of -1.03 ± 0.72 (range, -0.77 ± 0.98 to -1.20 ± 0.59) across evaluated doses (15 to 90 mg/kg), indicative of potential in vivo synergy.

An outbreak of cutaneous abscesses caused by Panton-Valentine leukocidin-producing methicillin-susceptible Staphylococcus aureus among gold mine workers, South Africa, November 2017 to March 2018.

BACKGROUND: We aimed to describe an outbreak of cutaneous abscesses caused by Panton-Valentine leukocidin (PVL)-producing methicillin-susceptible Staphylococcus aureus (MSSA) among gold mine workers. METHODS: In February 2018, we retrospectively reviewed a random sample of 50 medical records from 243 cases and conducted face-to-face interviews using a structured questionnaire. Pus aspirates were sent to the National Institute for Communicable Diseases from prospectively-identified cases (November 2017-March 2018). Nasopharyngeal swabs were collected during a colonisation survey in February 2018. Staphylococcus aureus isolates were screened with a conventional PCR for lukS/F-PV. Pulsed-field gel electrophoresis (PFGE) was performed to determine the genetic relatedness among the isolates. A sample of isolates were selected for whole genome sequencing (WGS). We conducted an assessment on biological risks associated with mining activities. RESULTS: From January 2017 to February 2018, 10% (350/3582) of mine workers sought care for cutaneous abscesses. Forty-seven medical files were available for review, 96% were male (n = 45) with a mean age of 43 years (SD = 7). About 52% (24/46) were involved in stoping and 28% (13/47) worked on a particular level. We cultured S. aureus from 79% (30/38) of cases with a submitted specimen and 14% (12/83) from colonisation swabs. All isolates were susceptible to cloxacillin. Seventy-one percent of S. aureus isolates (30/42) were PVL-PCR-positive. Six PFGE clusters were identified, 57% (21/37) were closely related. WGS analysis found nine different sequence types. PFGE and WGS analysis showed more than one cluster of S. aureus infections involving closely related isolates. Test reports for feed and product water of the mine showed that total plate counts were above the limits of 1000 cfu/ml, coliform counts > 10 cfu/100 ml and presence of faecal coliforms. Best practices were poorly implemented as some mine workers washed protective clothing with untreated water and hung them for drying at the underground surface. CONCLUSIONS: PVL-producing MSSA caused an outbreak of cutaneous abscesses among underground workers at a gold mining company. To our knowledge, no other outbreaks of PVL-producing S. aureus involving skin and soft tissue infections have been reported in mining facilities in South Africa. We recommend that worker awareness of infection prevention and control practices be strengthened.

Epidemiology and risk factors of Staphylococcus aureus CC398 bone and joint infections.

BACKGROUND: A particular ability of the Staphylococcus aureus clonal complex 398 (CC398) to cause bone and joint infections (BJI) remains questionable, since some studies have described high prevalence of MSSA CC398 in prosthetic joint infection (PJI) and diabetic foot ostemolyelitis (DFO). Here, we described the long-term epidemiology of CC398 among S. aureus isolated from BJI and identified risk factors associated with CC398. METHODS: We included all bone and joint samples with S. aureus-positive culture in our university hospital between January 2010 and December 2017. Logistic regression was used for univariate and multivariate analysis. RESULTS: We identified 124 CC398 isolates among the 958 BJI-associated S. aureus. The proportion of CC398 among S. aureus increased steadily from 4% in 2010 to 26% in 2017. Only 4 isolates of CC398 were resistant to methicillin. The distribution of BJI types due to CC398 and non CC398 isolates was similar. In multivariate analysis, age (p = 0.034, OR = 3.9), McCabe score (p = 0.005, OR = 5) and inoculation mechanism (p = 0.020, OR = 3.7) were associated with PJI-related CC398. The year of infection (p < 0.001, OR = 1.6), Charlson's score (p = 0.001, OR = 1.5) and grade 4 (severe) of the International Working Group of the Diabetic Foot classification (p < 0.001, OR = 8.5) were associated with DFO-related CC398. CONCLUSION: We highlighted here the emergence and spread of CC398-MSSA in BJI. Patients with comorbidities are at high risk of CC398 MSSA PJI and DFO. The spread of CC398 in the community and hospital settings remains unclear and further epidemiological studies are needed to identify the determinants of its success.

Genetic analysis of methicillin-susceptible Staphylococcus aureus clinical isolates: High prevalence of multidrug-resistant ST239 with strong biofilm-production ability.

BACKGROUND: The distributions of methicillin-susceptible Staphylococcus aureus (MSSA) are divers geographically with different genetic backgrounds. Data related to molecular characteristics of MSSA compare to methicillin-resistant Staphylococcus aureus (MRSA) is sparse. METHODS: In this cross-sectional study, antimicrobial susceptibility testing, virulence genes analysis, biofilm formation, accessory gene regulator (agr) typing, and multilocus sequence typing (MLST) characterized on 75 MSSA isolates. RESULTS: Multidrug-resistance MSSA was found to be 84%. Forty-eight (64%) isolates were toxinogenic with 34 and 14 isolates carrying pvl and tst representing 45.3% and 18.7%. The most common SE genes were sed (20%), sec (16%), and sea (16%). Fifty-five (73.3%) isolates were confirmed as biofilm producer with a markedly high prevalence of fnbA (93.3%), fnbB (86.7%), icaA (65.3%), icaD (53.3%), can (24%), ebp (10.7%), and bap (1.3%). A total of 3 agr types (I, 73.3%; III, 16%; II, 10.7%) and 4 clonal complexes (CCs) and sequence types (STs), namely CC8/ST293 (45.3%), CC/ST22 (28%), CC/ST30 (16%), and CC/ST5 (10.7%) were detected in this study. All the high and low-level mupirocin resistance strains belonged to ST239 and ST22 strains, respectively. All the fusidic acid-resistant isolates carried fusC and belonged to ST30. CONCLUSIONS: These findings indicated that ST239 with strong biofilm production ability is the most common type in MSSA strains isolated from patients. It seems that the antimicrobial resistance profiles, toxin, and biofilm formation were closely associated with specific STs. Further studies are required to identify and control of these clonal lineages in our area.

Burdens of Invasive Methicillin-Susceptible and Methicillin-Resistant Staphylococcus aureus Disease, Minnesota, USA.

During August 1, 2014-July 31, 2015, in 2 counties in Minnesota, USA, incidence of invasive methicillin-susceptible Staphylococcus aureus (MSSA) (27.1 cases/100,000 persons) was twice that of invasive methicillin-resistant S. aureus (13.1 cases/100,000 persons). MSSA isolates were more genetically diverse and susceptible to more antimicrobial drugs than methicillin-resistant S. aureus isolates.

Increasing incidence of bloodstream infections due to Staphylococcus aureus clonal complex 398 in a French hospital between 2010 and 2017.

The epidemiology of Staphylococcus aureus is changing and several surveillances worldwide have evidenced an increasing incidence of S. aureus bloodstream infections (BSIs). Here, we described the long-term epidemiology of the emergent clonal group CC398 among S. aureus isolated from BSIs in our French university hospital between 2010 and 2017. Each patient with at least one blood culture positive with S. aureus during the study period was included (N = 1455). Cefoxitin susceptibility was determined using the disk diffusion method according to EUCAST recommendations. CC398 isolates were first screened from the whole S. aureus collection with a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) typing method confirmed by a CC398-specific PCR. In our hospital, the incidence of hospital- and community-acquired BSIs due to S. aureus and MSSA increased in parallel between 2010 and 2017 while that of BSIs with MRSA decreased. The prevalence of CC398 isolates among S. aureus from BSIs increased from 3.6 in 2010 to 20.2% in 2017 (p < 0.05). CC398-MRSA emerged but remains very sparse. Our data suggested that CC398-MSSA disseminates in the community. We showed here the emergence and the diffusion of CC398-MSSA, a subclone associated with invasive infections, in our hospital. The monitoring of this particular human-adapted S. aureus clone is needed and genomic studies will have to identify the determinants of its diffusion.

Molecular characteristics and clinical features of pediatric methicillin-susceptible Staphylococcus aureus infection in a medical center in northern Taiwan.

BACKGROUND: There have been no reports regarding clinical features and molecular characteristics of childhood methicillin-susceptible Staphylococcus aureus (MSSA) infections in Taiwan. METHODS: We prospectively collected clinical S. aureus isolates from patients aged < 18 years in a university-affiliated hospital in 2015. Only the first isolate from each patient was included. Medical records were retrospectively reviewed. Patients were classified as community-associated (CA) or healthcare-associated (HA) by the epidemiologic criteria. All MSSA isolates were molecularly characterized. RESULTS: A total of 495 S. aureus isolates were identified, and 178 (36.0%) were MSSA. Among the 131 MSSA-infected patients enrolled, 94 (71.8%) were community-associated and 60 (45.8%) were inpatients. Patients with HA infections was significantly younger than those with CA infections (median, 15 vs. 67.5 months). The most common specimen of MSSA identified was pus or wound (73.3%). Compared to HA-MSSA, CA-MSSA isolates were significantly less frequently from sputum (6.4% vs. 27%, p = 0.001). Nineteen pulsotypes were identified. Four pulsotypes accounted for 60% of the isolates. Isolates of ST15/pulsotype F were more frequently seen in CA than in HA (p = 0.064) while isolates of ST188/pulsotype AX frequently seen in HA (p = 0.049). PVL genes were identified in 11 isolates (8.4%), nine of which were characterized as ST59/pulsotype D, same as the local endemic CA-MRSA clone. CONCLUSIONS: MSSA accounted for around one-third of childhood S. aureus infections in northern Taiwan. SSTI was the most common manifestation. The molecular characteristics of these clinical MSSA isolates were relatively diverse and had certain significant differences between CA and HA isolates.

Interventions to treat methicillin-susceptible Staphylococcus aureus bacteremia: many methodological concerns.

The aim of this letter was to point out some methodological concerns about an article written by Shi et al. and published in the journal. There is an increasing trend in the isolation of Methicillin-susceptible Staphylococcus aureus bacteremia and a variety of questions regarding the best therapy to treat this condition. These concerns might lead to selection, publication and information bias that prevent the generalization and application of these results in our clinical practice.

Efficacy of silver nanoparticles against multidrug resistant clinical Staphylococcus aureus isolates from Nigeria.

Multidrug resistant (MDR) S. aureus infections continue to account for excess mortality in hospital and community settings and constitute a rising global health problem. However, data on the efficacy and mechanism of actions of alternative solutions like silver nanoparticles in developing countries are lacking. This study investigated anti-staphylococcal activity of silver nanoparticles (AgNP) against local strains from Nigeria. A total 119 clinical isolates of S. aureus from five Nigerian laboratories categorized as MRSA (n = 52) and MSSA (n = 67) by PCR were studied. The MIC of AgNP produced by chemical reduction method and characterized by surface plasmon resonance absorbance and size equivalence by scanning electron microscopy was determined by microbroth dilution method. Its effect on protease activity and plasmids were also investigated. Baseline characteristics of the isolates revealed MDR phenotype of the isolates, carriage of diverse plasmids (15-32 kb) among the MDR MSSA, and mean extracellular protease activity of 24.8-55.7 U/mL. The chemically synthesized AgNP had a peak absorbance at 400 nm with a size equivalence of 4.58 nm. The MICs of AgNP against the isolates were 4.7 µg/mL and 4.9 µg/mL, respectively, for MRSA and MSSA (P > 0.05). The bactericidal effect of AgNP at 2.5-5 µg/mL on the MSSA and MRSA isolates was observed at 2.7-5.5 h post exposure in vitro. Further analysis revealed plasmid eviction in the MDR MSSA isolates exposed to 5 µg/mL AgNP and dose-dependent reduction in extracellular protease activity by 84.6-93.1%. Hemolysis of human erythrocytes by AgNP was not observed at the MIC range. Conclusion: This study revealed safety and efficacy of AgNP against clinical MDR S. aureus isolates from Nigeria, using plasmid eviction and protease inhibition as mechanisms of action.

A Retrospective Analysis of Treatment and Clinical Outcomes among Patients with Methicillin-Susceptible Staphylococcus aureus Bloodstream Isolates Possessing Detectable mecA by a Commercial PCR Assay Compared to Patients with Methicillin-Resistant Staphylococcus aureus Bloodstream Isolates.

mecA-positive Staphylococcus aureus isolates phenotypically susceptible to cefoxitin (mecA-methicillin-sensitive S. aureus [MSSA]) have been identified. We describe the treatment and outcomes among patients with mecA-MSSA bloodstream infections (BSI) and MRSA BSI matched 1:1 for age, BSI origin, and BSI type (n = 17 per group). Compared to MRSA BSI patients, mecA-MSSA BSI patients more often experienced clinical failure (58.8% and 11.8%, P = 0.010), driven largely by persistent bacteremia (35.3% and 11.8%). mecA-MSSA BSI patients may be at higher risk for poor clinical outcomes.

Nasal colonisation, antimicrobial susceptibility and genotypic pattern of Staphylococcus aureus among agricultural biotechnology students in Besut, Terengganu, east coast of Malaysia.

BACKGROUND: This study aimed to profile the antimicrobial susceptibility and presence of resistance and virulence genes of methicillin-susceptible Staphylococcus aureus (MSSA) and MRSA nasal carriage, by means of genotypic analyses, in students of a tertiary institution in the state of Terengganu, east coast of Malaysia. METHODS: A total of 370 agricultural biotechnology students from Universiti Sultan Zainal Abidin in Besut, Terengganu, were enrolled in this study. Antimicrobial susceptibility profiles were evaluated by standard methods. PCR detection of resistance and virulence genes was performed on S. aureus that were methicillin-resistant, macrolide-lincosamide-streptogramin B (MLSB )-positive phenotype and/or positive for the leukocidin (pvl) gene followed by staphylococcal cassette chromosome mec (SCCmec), staphylococcal protein A (spa) and accessory gene regulator (agr) typing. RESULTS: One hundred and nineteen of 370 students carried S. aureus (32%); 18 of the isolates were MRSA (15%). Erythromycin resistance was detected in 20% (24/119) of which 15% (18/119) were MRSA and 5% (6/119) MSSA. Among the 24 erythromycin-resistant isolates, D-test was positive in 29% (7/24) displaying inducible MLSB , whereas the remaining 71% (17/24) showed constitutive MLSB phenotypes. Nine (7.6%) of 119 isolates were pvl positive: 44% MRSA (4/9) and 56% MSSA (5/9). Staphylococcal surface protein sasX gene was present in 92% of MRSA and 8% of MSSA isolates. The majority of MRSA isolates were agr type I (15/18; 83%). Five spa types identified with spa t037 were predominant, followed by spa types (t304 and t8696) as newly reported Malaysian MRSA in a community setting. CONCLUSION: The presence of MRSA with SCCmec of hospital-associated features and globally recognised spa types in community setting is worrisome. Furthermore, the presence of MLSB strains among multidrug-resistant (MDR) S. aureus with sasX as well as pvl-positive isolates highlights the potential risk of a community setting in facilitating the dissemination of both virulence and resistance determinants.

Predictors of colonization with Staphylococcus species among patients scheduled for cardiac and orthopedic interventions at tertiary care hospitals in north-eastern Germany-a prevalence screening study.

As methicillin-resistant Staphylococcus aureus (MRSA) colonization and infection in humans are a global challenge. In Mecklenburg and Western Pomerania (Germany) 1,517 patients who underwent surgical interventions were systematically screened for MRSA and MSSA colonization on the day of hospital admission and discharge. Demographic data, risk factors and colonization status of the (i) nose, (ii) throat, (iii) groin, and (iv) thorax or site of surgical intervention were determined. Of the 1,433 patients who were included for further evaluation, 331 (23.1%) were colonized with MSSA, while only 17 (1.2%) were MRSA carriers on the day of hospital admission. A combination of nose, throat and groin swabs returned a detection rate of 98.3% for MSSA/MRSA. Trauma patients had lower prevalence of MRSA/MSSA (OR 0.524, 95% CI: 0.37-0.75; p < 0.001) than patients with intended orthopedic interventions. Males showed significantly higher nasal S. aureus carrier rates than females (odds ratio (OR) = 1.478; 95% CI: 1.14-1.92; p = 0.003). Nasal S. aureus colonization was less frequent among male smokers as compared to non-smokers (chi2 = 16.801; phi = 0.154; p < 0.001). Age, gender and smoking had a significant influence on S. aureus colonization. Combining at least three different swabbing sites should be considered for standard screening procedure to determine S. aureus colonization at patients scheduled for cardiac or orthopedic interventions at tertiary care hospitals.

Efficacy and safety of cefazolin versus antistaphylococcal penicillins for the treatment of methicillin-susceptible Staphylococcus aureus bacteremia: a systematic review and meta-analysis.

BACKGROUND: Antistaphylococcal penicillins (ASPs) and cefazolin have become the most frequent choices for the treatment of methicillin-susceptible Staphylococcus aureus (MSSA) infections. However, the best therapeutic agent to treat MSSA bacteremia remains to be established. METHODS: We conducted a systematic review and meta-analysis to evaluate the efficacy and safety of these two regimens for the treatment of MSSA bacteremia. PubMed, EMBASE and the Cochrane Library from inception to February 2018 were searched. The primary outcome was mortality. The secondary outcomes included treatment failure, recurrence of bacteremia, adverse effects (AEs) and discontinuation due to AEs. Data were extracted and pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. RESULTS: A total of ten observational studies met the inclusion criteria. The results indicate that compared to ASPs, cefazolin was associated with significant reduction in mortality (OR, 0.69; 95% CI, 0.58 to 0.82; I2 = 3.4%) and clinical failure (OR, 0.56; 95% CI, 0.37 to 0.85; I2 = 44.9%) without increasing the recurrence of bacteremia (OR, 1.12; 95% CI, 0.94 to 1.34; I2 = 0%). There were no significant differences for the risk of anaphylaxis (OR, 0.91; 95% CI, 0.36 to 2.99; I2 = 0%) or hematotoxicity (OR, 0.56; 95% CI, 0.17 to 1.88; I2 = 0%). However, nephrotoxicity (OR, 0.36; 95% CI, 0.16 to 0.81; I2 = 0%) and hepatotoxicity (OR, 0.12; 95% CI, 0.04 to 0.41; I2 = 0%) were significantly lower in the cefazolin group. Moreover, cefazolin was associated with lower probability of discontinuation due to AEs compared with the ASPs (OR, 0.24; 95% CI, 0.12 to 0.48; I2 = 18%). CONCLUSION: The results of present study favor the application of cefazolin and should be regarded as important evidence to help make clinical decisions in choosing a treatment option for treating MSSA bacteremia.