We developed two colorimetric methods for the detection of vancomycin- and oxacillin-resistant Staphylococcus aureus in </=6 h: (i) a nitrate reductase assay and (ii) a resazurin microplate method. MICs agreed with results obtained by CLSI methods for oxacillin. However, detection of vancomycin resistance required a larger inoculum. These methods may be recommended for the detection of vancomyc...

One hundred four Enterobacter isolates were tested by standard CLSI disk diffusion methods for detecting extended-spectrum beta-lactamases (ESBLs) and with cefepime-clavulanate disk combinations. SHV-12 was produced by 8.7% of isolates. The cefepime-clavulanate combination provided 88% sensitivity and 91% specificity for the detection of SHV-12 ESBL.

In defined, isogenic strains, at least three mutations, two of which must be in gyrA, were required to exceed the CLSI breakpoint for fluoroquinolone resistance. Strains with double mutations in both gyrA and parC had even higher MICs of fluoroquinolones than strains with totals of three mutations.

Using the updated 2010 CLSI carbapenem breakpoints for the Enterobacteriaceae, nonsusceptibility to ertapenem and imipenem predicted the presence of bla(KPC) poorly, especially among Escherichia coli and Enterobacter species. In regions where KPC-producing bacteria are endemic, testing for nonsusceptibility to meropenem may provide improved accuracy in identifying these isolates.

Methods The ocular samples viz., corneal swab, corneal scraping, aqueous tap and vitreous tap were processed for culture and the isolated Nocardia species were further confirmed for speciation by standard microbiological procedures. Antibiotic susceptibility analysis for the confirmed isolates of N. asteroides was performed by agar disk diffusion method following the guidelines of Clinical Labo...

The in vitro activity of ceftaroline was compared with those of ceftriaxone, clindamycin, imipenem, metronidazole, moxifloxacin, tigecycline, and vancomycin against 514 clinical anaerobic isolates using Clinical and Laboratory Standards Institute (CLSI) standard methodology. Ceftaroline demonstrated good to excellent activity against Gram-positive anaerobic pathogens and limited activity agains...

Cases of invasive mycosis due to Blastobotrys serpentis and B. proliferans identified by sequencing in a preterm patient and a rhabdomyosarcoma patient, respectively, are reported. Both species revealed elevated fluconazole and echinocandin MICs by the CLSI broth microdilution method. Additionally, B. serpentis exhibited high amphotericin B MICs, thus posing serious therapeutic challenges.

We investigated if CLSI M27-A2 Candida species breakpoints for fluconazole MIC are valid when read at 24 h. Analysis of a data set showed good correlation between 48- and 24-h MICs, as well as similar outcomes and pharmacodynamic efficacy parameters, except for isolates in the susceptible dose-dependent category, such as Candida glabrata.

The in vitro susceptibilities of 59 avian Aspergillus fumigatus strains to amphotericin B, itraconazole, and voriconazole were determined using the standard microdilution broth method (CLSI M38-A2). Four isolates showed acquired resistance to itraconazole and voriconazole, harboring implications for the treatment of aspergillosis in both birds and humans.

The aim of this study was to establish standardized drug susceptibility testing (DST) methodologies and reference MIC quality control (QC) ranges for bedaquiline, a diarylquinoline antimycobacterial, used in the treatment of adults with multidrug-resistant tuberculosis. Two tier-2 QC reproducibility studies of bedaquiline DST were conducted in eight laboratories using Clinical Laboratory and St...