A challenge panel of enterococci (n = 50) and staphylococci (n = 50), including 17 and 15 isolates that were nonsusceptible to linezolid, respectively, were tested with the Clinical and Laboratory Standards Institute broth microdilution and disk diffusion reference methods. In addition, all 100 isolates were tested in parallel by Etest (AB Biodisk, Solna, Sweden), MicroScan WalkAway (Dade, West...

BACKGROUND Recent studies have reported a greater probability of vancomycin treatment failure in methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections caused by strains with a vancomycin MIC ≥ 1.5 mg/L. However, previous reports included patients treated without adjustments based on vancomycin serum levels and with different methods to evaluate MICs, which may render differe...

A study was designed to evaluate the modified Hodge test (MHT), Mastdiscs ID inhibitor combination disks (MDI), Rosco Diagnostica Neo-Sensitabs (RDS), metallo-β-lactamase (MBL) Etest, and in-house multiplex PCR for the detection of well-characterized carbapenemase-producing Enterobacteriaceae. One hundred forty-two nonrepeat clinical isolates of carbapenemase-producing Enterobacteriaceae (inclu...

The performance of the Etest for posaconazole (SCH 56592) susceptibility testing of 314 isolates of Candida spp. was assessed against the National Committee for Clinical Laboratory Standards (NCCLS) microdilution broth method. The NCCLS method employed RPMI 1640 broth medium, and MICs were read after incubation for 48 h at 35 degrees C. MICs were determined by Etest for all 314 isolates with RP...

OBJECTIVES The aim of this study was to establish the relationship between reduced vancomycin and daptomycin susceptibility among Australasian vancomycin-intermediate Staphylococcus aureus (VISA) and heterogeneous-VISA (hVISA) isolates from patients never exposed to daptomycin. METHODS Forty-seven stored clinical isolates of hVISA/VISA collected before November 2008 from around Australia and ...

Extended-spectrum beta-lactamase (ESBL) production in members of the Enterobacteriaceae can confer resistance to extended-spectrum cephalosporins, aztreonam, and penicillin. As such, the accurate detection of ESBL producers is essential for the appropriate selection of antibiotic therapy. Twenty previously characterized isolates and 49 clinical isolates suspected of ESBL production were tested ...

OBJECTIVES Trimethoprim/sulfamethoxazole is commonly used to treat melioidosis. Antimicrobial susceptibility testing using the disc diffusion method is commonly used in melioidosis-endemic areas, but may overestimate resistance to trimethoprim/sulfamethoxazole. PATIENTS AND METHODS We performed disc diffusion and Etest on isolates from the first positive culture for all patients presenting to...

Seven commercial systems for antimicrobial susceptibility testing of Streptococcus pneumoniae were evaluated by using a challenge set of 55 pneumococcal isolates with a variety of resistance phenotypes and genotypes. Overall, the results produced by the Pasco and Etest methods were found to be acceptable for all drugs tested except for trimethoprim-sulfamethoxazole testing by the Etest. The Jus...

Fluconazole MICs obtained with the modified BMD tests and Etest read at 24 and 48 h were compared with the reference BMD MICs read at 48 h. Discrepancies between MICs of no more than ±1 dilution were used to calculate the percentage of agreement. Categorical agreement was defined when the applied method gave the same category result compared with the reference BMD category read at 48 h. Results...

and these results were considered the reference standard against which all other results were compared. Temocillin Etests were used according to the manufacturer's instructions. Susceptibility to temocillin using the Phoenix system was determined according to BSAC breakpoints for Enterobacteriaceae for systemic infections (susceptible if MIC ≤8 mg/L). 3 If the Etest or Phoenix results were with...