Adjunctive rifampicin for Staphylococcus aureus bacteraemia (ARREST): a multicentre, randomised, double-blind, placebo-controlled trial.

BACKGROUND: Staphylococcus aureus bacteraemia is a common cause of severe community-acquired and hospital-acquired infection worldwide. We tested the hypothesis that adjunctive rifampicin would reduce bacteriologically confirmed treatment failure or disease recurrence, or death, by enhancing early S aureus killing, sterilising infected foci and blood faster, and reducing risks of dissemination and metastatic infection. METHODS: In this multicentre, randomised, double-blind, placebo-controlled trial, adults (≥18 years) with S aureus bacteraemia who had received ≤96 h of active antibiotic therapy were recruited from 29 UK hospitals. Patients were randomly assigned (1:1) via a computer-generated sequential randomisation list to receive 2 weeks of adjunctive rifampicin (600 mg or 900 mg per day according to weight, oral or intravenous) versus identical placebo, together with standard antibiotic therapy. Randomisation was stratified by centre. Patients, investigators, and those caring for the patients were masked to group allocation. The primary outcome was time to bacteriologically confirmed treatment failure or disease recurrence, or death (all-cause), from randomisation to 12 weeks, adjudicated by an independent review committee masked to the treatment. Analysis was intention to treat. This trial was registered, number ISRCTN37666216, and is closed to new participants. FINDINGS: Between Dec 10, 2012, and Oct 25, 2016, 758 eligible participants were randomly assigned: 370 to rifampicin and 388 to placebo. 485 (64%) participants had community-acquired S aureus infections, and 132 (17%) had nosocomial S aureus infections. 47 (6%) had meticillin-resistant infections. 301 (40%) participants had an initial deep infection focus. Standard antibiotics were given for 29 (IQR 18-45) days; 619 (82%) participants received flucloxacillin. By week 12, 62 (17%) of participants who received rifampicin versus 71 (18%) who received placebo experienced treatment failure or disease recurrence, or died (absolute risk difference -1·4%, 95% CI -7·0 to 4·3; hazard ratio 0·96, 0·68-1·35, p=0·81). From randomisation to 12 weeks, no evidence of differences in serious (p=0·17) or grade 3-4 (p=0·36) adverse events were observed; however, 63 (17%) participants in the rifampicin group versus 39 (10%) in the placebo group had antibiotic or trial drug-modifying adverse events (p=0·004), and 24 (6%) versus six (2%) had drug interactions (p=0·0005). INTERPRETATION: Adjunctive rifampicin provided no overall benefit over standard antibiotic therapy in adults with S aureus bacteraemia. FUNDING: UK National Institute for Health Research Health Technology Assessment

SmaI Restriction Site-Based Multiplex PCR for Typing of Hospital- and Community-Acquired Staphylococcus aureus▿

Methicillin-resistant Staphylococcus aureus (MRSA) is an important nosocomial pathogen, and morbidity and mortality rates associated with this pathogen have increased markedly in recent years. MRSA strains are generally resistant to several classes of antibiotics and are therefore difficult and costly to treat. A major issue is to identify the sources of MRSA infections and to monitor their epidemic spread. In this study, we report the development of a typing technique for S. aureus, based on single-nucleotide polymorphism (SNP) variations in and around SmaI-restriction sites (CCCGGG). An assessment of the SmaI restriction site-based multiplex PCR (SmaI-multiplex PCR) typing (SMT) with respect to pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) revealed a high level of concordance in the clustering of the test strains. The SmaI-multiplex PCR was found to be more discriminatory than MLST/staphylococcal cassette chromosome mec (SCCmec) typing but less discriminatory than PFGE. SMT can provide real-time information for the investigation of ongoing S. aureus hospital outbreaks. SMT meets the criteria of a practical typing method: it is simple, reproducible, and highly discriminatory and does not require expensive equipment or specialist expertise. Consequently, SmaI-multiplex PCR has the potential to be used in routine clinical microbiology laboratories

Antibiotic Review Kit for Hospitals (ARK-Hospital): a stepped wedge cluster randomised controlled trial

Background: Strategies to reduce antibiotic overuse in hospitals depend on prescribers taking decisions to stop unnecessary antibiotics. There is limited evidence on how to support this. We evaluated a multifaceted behaviour change intervention (ARK) designed to reduce antibiotic use among adult acute/medical inpatients by increasing appropriate decisions to stop antibiotics at clinical review. Methods: We performed a stepped-wedge, cluster (hospital)-randomised controlled trial using computer-generated sequence randomisation of 39 hospitals in 7 calendar-time blocks in the United Kingdom (25/September/2017-01/July/2019). Randomised implementation date was concealed until 12 weeks before implementation, when local preparations were designed to start. Co-primary outcomes were monthly antibiotic defined-daily-doses (DDD) per adult acute/medical admission (hospital-level, superiority) and all-cause 30-day mortality (patient level, non-inferiority, margin 5%). Sites were eligible if they admitted non-elective medical patients, could identify an intervention “champion”, and provide study data. Sites werefollowed for at least 14 months. Intervention effects were assessed using interrupted timeseries analyses within each site, estimating overall effects through random-effects meta analysis, with heterogeneity across prespecified potential modifiers assessed using meta regression.Trial registration: ISRCTN12674243.Findings: Adjusted estimates showed reductions in total antibiotic DDDs per acute/medicaladmission (-4.8% per year, 95% CI: -9.1%,-0.2%) following the intervention. Among7,160,421 acute/medical admissions, there were trends towards -2.7% (95% CI: -5.7%,+0.3%) immediate and +3.0% (95% CI: -0.1%,+6.2%) sustained changes in adjusted30-day mortality. Site-specific mortality trends were unrelated to the site-specific magnitudeof antibiotic reduction (Spearman’s ρ=0.011, p=0.949). Whilst 90-day mortality oddsappeared to increase (+3.9%, 95% CI: +0.5%,+7.4%), this was attenuated excludingadmissions after COVID-19 onset (+3.2%, 95% CI:-1.5%,+8.2%). There was no evidence ofintervention effects on length-of-stay (p>0.4).Interpretation: The weak, inconsistent intervention effects on mortality are likely explained by the post-implementation onset of the COVID-19 pandemic. The ARK intervention resulted in sustained, safe reductions in antibiotic use among adult acute/medical inpatients. Funding: NIHR Programme Grants for Applied Research, RP-PG-0514-20015