Background Timely availability of microbiological results from positive blood cultures is essential to enable early pathogen-directed therapy. The Accelerate Pheno system (ADX) is a novel technology using fluorescence in situ hybridization for rapid species identification (ID) and morphokinetic bacterial analysis for phenotypic antimicrobial susceptibility testing (AST), with promising results. Yet the impact of this technology on clinical management and patient outcome remains unclear. Methods We conducted a quasiexperimental before-and-after observational study and analyzed 3 groups with different diagnostic and therapeutic pathways following recent integration of ADX: conventional microbiological diagnostics with and without antimicrobial stewardship program (ASP) intervention, and rapid diagnostics (ADX in addition to conventional standard) with ASP intervention. Primary endpoints were time to adequate, to optimal and to step-down antimicrobial therapy. Secondary endpoints were antimicrobial consumption, in-hospital mortality, length of stay (LOS), and the incidence of Clostridioidesdifficile infection (CDI). Results Two hundred four patients (conventional diagnostics, n = 64; conventional diagnostics + ASP, n = 68; rapid diagnostics + ASP; n = 72) were evaluated. The use of ADX significantly decreased time from Gram stain to ID (median, 23 vs 2.2 hours, P < .001) and AST (median, 23 vs 7.4 hours, P < .001), from Gram stain to optimal therapy (median, 11 vs 7 hours, P = .024) and to step-down antimicrobial therapy (median, 27.8 vs 12 hours, P = .019). However, groups did not differ in antimicrobial consumption, duration of antimicrobial therapy, mortality, LOS, or incidence of CDI. Conclusions Use of ADX significantly reduced time to ID and AST as well as time to optimal antimicrobial therapy but did not affect antimicrobial consumption and clinical outcome.

BackgroundClostridium difficile infection (CDI) is a major cause of hospital-acquired diarrhea. Secondary bile acids were shown to confer resistance to colonization by C. difficile. 7α-dehydroxylation is a key step in transformation of primary to secondary bile acids and required genes have been located in a single bile acid-inducible (bai) operon in C. scindens as well as in C. hiranonis, two Clostridium sp. recently reported to protect against C. difficile colonization.AimTo analyze baiCD gene abundance in C. difficile positive and negative fecal samples.Material & methodsA species-specific qPCR for detecting baiCD genes was established. Fecal samples of patients with CDI, asymptomatic toxigenic C. difficile colonization (TCD), non-toxigenic C. difficile colonization (NTCD), of C. difficile negative (NC) patients, and of two patients before and after fecal microbiota transplantation (FMT) for recurrent CDI (rCDI) were tested for the presence of the baiCD genes.ResultsThe prevalence of the baiCD gene cluster was significantly higher in C. difficile negative fecal samples than in samples of patients diagnosed with CDI (72.5% (100/138) vs. 35.9% (23/64; p<0.0001). No differences in baiCD gene cluster prevalence were seen between NC and NTCD or NC and TCD samples. Both rCDI patients were baiCD-negative at baseline, but one of the two patients turned positive after successful FMT from a baiCD-positive donor.ConclusionFecal samples of CDI patients are less frequently baiCD-positive than samples from asymptomatic carriers or C. difficile-negative individuals. Furthermore, we present a case of baiCD positivity observed after successful FMT for rCDI.

Especially CDAD recurrence was associated with excessive costs, which were mostly attributable to a significantly longer overall length of stay. Innovative treatment strategies are warranted to reduce treatment costs and prevent recurrence of CDAD.

cThis study evaluated the impact of preenrichment on the detection of extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) in clinical stool samples. ESBL-E were detected in 41 of 343 patients (12.0%). As 31.7% of the ESBL-E carriers were identified by preenrichment, only this additional diagnostic step significantly improved the detection of ESBL-E. E xtended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) are increasingly reported worldwide. Treatment options for infections due to these organisms are limited, and initial empirical therapy is often inappropriate and is associated with increased morbidity and mortality (1). ESBL-E carriers are known to develop bacteremia with the isolates colonizing the patients' intestines (2). Therefore, in many hospitals, risk-adapted screening for ESBL-E carriage is performed, but limited data exist on the optimal screening strategy. Currently, laboratory detection of ESBL-E in fecal specimens mostly relies on culture methods using selective agar medium. This method has a modest sensitivity (3). Preenrichment of swabs is used by many laboratories for methicillin-resistant Staphylococcus aureus (MRSA) screening and has demonstrated significantly improved sensitivity (4). To our knowledge, the impact of preenrichment on ESBL-E detection in stool samples has not been systematically investigated. In our study, we compared three different selective and nonselective broths for the detection of ESBL-E in clinical stool samples to the standard procedure-direct plating on ESBL agar.(This study was presented in part as a poster at the 25th European Congress of Clinical Microbiology and Infectious Diseases, Copenhagen, Denmark, 25 to 28 April 2015.) From September 2013 to March 2014, 496 stool samples submitted for ESBL-E screening from 343 patients at the University Hospital Cologne, a 1,400-bed tertiary care facility, were included in the study. All samples were stored at 4°C and were processed within 24 h of receipt. A pea-sized portion of solid stool or 250 l of liquid stool was suspended in 1 ml 0.9% NaCl to reach a standardized inoculum. One hundred microliters of the stool suspension was inoculated directly onto chromID ESBL agar (bioMérieux, Marcy l'Etoile, France) and into 5 ml of nonselective tryptic soy broth (TSB), MacConkey (MC) broth (Roth, Germany, Karlsruhe) selecting only Gram-negative rods, and MacConkey broth supplemented with cefuroxime (32 mg/liter) and vancomycin (64 mg/liter) (MC-CV) additionally inhibiting the nonresistant Gram-negative flora and further inhibiting Grampositive bacteria. Each medium was stored and processed according to the manufacturers' instructions.Agar plates and broths were incubated at 36°C Ϯ 1°C in ambient air for 18 h to 24 h. Using calibrated inoculation loops, 10 l of the respective enrichment broth was inoculated onto ESBL agar, which was incubated at 36°C Ϯ 1°C in ambient air for another 18 h to 24 h. Plates were interpreted according to the manufacturer's instructions. Uncolored colonies growing on ...