Multicenter Evaluation of the Accelerate PhenoTest BC Kit for Rapid Identification and Phenotypic Antimicrobial Susceptibility Testing Using Morphokinetic Cellular Analysis.

We describe results from a multicenter study evaluating the Accelerate Pheno system, a first of its kind diagnostic system that rapidly identifies common bloodstream pathogens from positive blood cultures within 90 min and determines bacterial phenotypic antimicrobial susceptibility testing (AST) results within ∼7 h. A combination of fresh clinical and seeded blood cultures were tested, and results from the Accelerate Pheno system were compared to Vitek 2 results for identification (ID) and broth microdilution or disk diffusion for AST. The Accelerate Pheno system accurately identified 14 common bacterial pathogens and two spp.

Performance of Ceftolozane-Tazobactam Etest, MIC Test Strips, and Disk Diffusion Compared to Reference Broth Microdilution for β-Lactam-Resistant Pseudomonas aeruginosa Isolates.

The performance characteristics of the ceftolozane-tazobactam (C-T) Etest (bioMérieux, Marcy l'Etoile, France), MIC test strips (MTS; Liofilchem, Italy), and disk diffusion (Hardy, Santa Ana, CA) were evaluated for a collection of 308 beta-lactam-resistant isolates of recovered from three institutions in Los Angeles, CA. Reference testing was performed by the reference broth microdilution (rBMD) method. MIC and disk results were interpreted using Clinical and Laboratory Standards Institute breakpoints.

Activity of Ceftolozane-Tazobactam and Ceftazidime-Avibactam against Beta-Lactam-Resistant Pseudomonas aeruginosa Isolates.

Ceftolozane-tazobactam (C/T) and ceftazidime-avibactam (CZA) MICs were evaluated for a collection of 309 beta-lactam-resistant isolates of recovered from three institutions in the area of Los Angeles, CA. Overall, 12.0% of isolates were susceptible to imipenem, 15.

Use of Ancillary Carbapenemase Tests To Improve Specificity of Phenotypic Definitions for Carbapenemase-Producing Enterobacteriaceae.

Carbapenemase-producing (CPE) are a significant threat to public health. In 2015, CDC revised the surveillance definition for CPE to include all resistant to any carbapenem tested. However, this definition is associated with poor specificity.

Multicenter Evaluation of a Modified Cefoxitin Disk Diffusion Method and PBP2a Testing To Predict mecA-Mediated Oxacillin Resistance in Atypical Staphylococcus aureus.

Phenotypic variants of Staphylococcus aureus that display small colonies, reduced pigmentation, and decreased hemolysis and/or coagulase activity are periodically isolated by the clinical laboratory. Antimicrobial susceptibility testing (AST) of these isolates is complicated, because many do not grow on routine AST media, including Mueller-Hinton agar (MHA) and cation-adjusted Mueller-Hinton broth. This multicenter study evaluated cefoxitin disk diffusion for 37 atypical S.

First Report of Ceftazidime-Avibactam Resistance in a KPC-3-Expressing Klebsiella pneumoniae Isolate.

Ceftazidime-avibactam is the first antimicrobial approved by the U.S. FDA for the treatment of carbapenem-resistant Enterobacteriaceae.

In vitro activity of daptomycin in combination with β-lactams, gentamicin, rifampin, and tigecycline against daptomycin-nonsusceptible enterococci.

Enterococci that are nonsusceptible (NS; MIC > 4 μg/ml) to daptomycin are an emerging clinical concern. The synergistic combination of daptomycin plus beta-lactams has been shown to be effective against vancomycin-resistant Enterococcus (VRE) species in vitro. This study systematically evaluated by in vitro time-kill studies the effect of daptomycin in combination with ampicillin, cefazolin, ceftriaxone, ceftaroline, ertapenem, gentamicin, tigecycline, and rifampin, for a collection of 9 daptomycin-NS enterococci that exhibited a broad range of MICs and different resistance-conferring mutations.

Comparison of the AmpliVue, BD Max System, and illumigene Molecular Assays for Detection of Group B Streptococcus in Antenatal Screening Specimens.

The performances of the AmpliVue, BD Max, and illumigene group B Streptococcus (GBS) nucleic acid amplification tests (NAATs) were compared to that of enriched culture for detection of GBS in antenatal screening specimens. Two hundred specimens were tested simultaneously with the NAATs, following 18 to 24 h of Lim broth enrichment; 15% of specimens were culture positive for GBS, whereas 31.5% were positive by at least one NAAT.

Comparison of the Vitek MS and Bruker Microflex LT MALDI-TOF MS platforms for routine identification of commonly isolated bacteria and yeast in the clinical microbiology laboratory.

This study compared the diagnostic performance of Bruker's Microflex LT and bioMérieux's Vitek MS matrix-assisted laser desorption ionization-time of flight mass spectrometry systems. A total of 477 isolates were tested on both instruments. Discrepant results were resolved by sequencing.