Methicillin-resistant Staphylococcus aureus (MRSA) is an important human pathogen, and colonisation with this organism can result in localised or systemic infections which may be fatal. One hundred in-patients admitted to a London teaching hospital and 100 out-patients attending prosthetic dentistry clinics were recruited into this study. Of the 100 out-patients, 27 % harboured S. aureus on their dentures, compared to 33 % of in-patients. Only one out-patient had MRSA colonising their dentures whereas 12 % of the in-patients harboured MRSA. The median total bacterial count of the denture plaque samples was 6.2 × 10(7) cfu/sample and 6.9 × 10(7) cfu/sample for the out-patient and in-patient populations, respectively. In most instances, where present, S. aureus comprised less than 1 % of the total viable denture microbiota. Phage typing demonstrated that EMRSA-15 and non-typeable strains were harboured on dentures. The results of this study have revealed that dentures are a potential reservoir of MRSA and so account should be taken of these findings when planning decontamination procedures for elimination of this pathogen.

BackgroundRapid organism identification and antimicrobial susceptibility testing (AST) can optimize antimicrobial therapy in patients with bacteraemia. The Accelerate Pheno™ system (ACC) can provide identification and AST results within 7 h of a positive culture.ObjectivesTo assess the hypothetical impact of ACC on time to effective therapy (TTET), time to definitive therapy (TTDT) and antimicrobial usage at the Detroit Medical Center (DMC).MethodsPatients with positive blood cultures from 29 March to 24 June 2016 were included. ACC was performed in parallel with normal laboratory procedures, but results were not made available to the clinicians. The potential benefit of having ACC results was determined if clinicians modified therapy based on actual AST results. Potential changes in TTET, TTDT and antibiotic usage were calculated.ResultsOne hundred and sixty-seven patients were included. The median TTET was 2.4 h (IQR 0.5, 15.1). Had ACC results been available, TTET could have been improved in four patients (2.4%), by a median decrease of 18.9 h (IQR 11.3, 20.4). The median TTDT was 41.4 h (IQR 21.7, 73.3) and ACC results could have improved TTDT among 51 patients (30.5%), by a median decrease of 25.4 h (IQR 18.7, 37.5). ACC implementation could have led to decreases in usage of cefepime (16% reduction), aminoglycosides (23%), piperacillin/tazobactam (8%) and vancomycin (4%).ConclusionsACC results could potentially improve time to de-escalation and reduce use of antimicrobials. The impact of ACC on TTET was small, likely related to the availability of other rapid diagnostic tests at DMC.

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BackgroundRapid organism identification (ID) and antimicrobial susceptibility testing (AST) can improve time to adequate therapy (TTAT) and optimal (TTOT). The Accelerate Pheno™ system (ACC) can provide ID and AST results within 7 hours. The objective of this study was to assess the hypothetical impact of ACC on TTAT and TTOT in a hospital with an established antimicrobial stewardship program and rapid genotypic organism and resistance marker ID.MethodsPatients with positive blood cultures, at the Detroit Medical Center, from March 29, 2016–June 14, 2016, were retrospectively reviewed. ACC was run on unique blood cultures as part of the laboratory validation of the system. ACC results were not made available to clinicians. These results were utilized to determine the hypothetical impact on TTAT and TTOT that the ACC results would have had in real-time. This assessment was performed based on how clinicians modified antimicrobial therapy with regards to antibiotic choice and timing, once ID or AST were known. The assumption was that the same decisions that were made at the time of traditional AST would have been made when ACC information would have been available. In addition, the impact of ACC on total antimicrobial usage was assessed.ResultsThe analysis included 148 patients. The median actual TTAT was 2.2 hours [interquartile range (IQR) 0.5–12.5 hours]. If ACC results had been available, TTAT could have been improved in 11 patients (7%), with a median potential decrease in the TTAT of 2.3 hours [IQR, 0.8–20.7]. The median actual TTOT was 40.7 hours [IQR, 21.3–74.1]. If ACC results were available, improved TTOT could have been achieved in 59 patients (40%), with a median potential decrease in TTOT of 24.2 hours [IQR 15.3–34.9]. The TTOT would have been achieved by earlier de-escalation in 53/59 (89.8%) patients. ACC implementation could have led to decreases in antibiotic usage for cefepime (17% reduction of actual use), aminoglycosides (23%), piperacillin/tazobactam (8%), and vancomycin (5%).ConclusionGiven the aggressive nature of empiric therapy and the availability of other rapid diagnostic tests at our center, ACC would have had a minimal impact TTAT. However, largely due to the ability to more rapidly de-escalate, ACC could have led to a more rapid TTOT in 40% of patients, and significantly reduced the use of broad-spectrum antimicrobials.Disclosures K. Kaye, Zavante Therapeutics, Inc.: Scientific Advisor, Consulting fee.