Frequencies of vanB-type Enterococcus faecium increased in Europe during the last years. VanB enterococci show various levels of vancomycin MICs even below the susceptible breakpoint challenging a reliable diagnostics. The performance of 3 chromogenic vancomycin-resistant enterococci (VRE) screening agars, 2 Etest® vancomycin protocols, and different microdilution methods to detect 129 clinical...

A recent study reporting surprisingly high beta-lactam MICs against beta-lactamase-negative ampicillin-resistant (BLNAR) strains when tested by the Etest prompted us to compare results of the Etest with those of the standard broth microdilution concerning BLNAR strains (5). In that study, the MIC90s of BLNAR and beta-lactamase-positive amoxicillinclavulanate-resistant (BLPACR) strains in respon...

OBJECTIVES To determine the correlation between various vancomycin MIC testing methodologies and explore the phenomenon of MIC creep. METHODS A total of 417 consecutive non-duplicate methicillin-resistant Staphylococcus aureus (MRSA) bloodstream isolates from Liverpool Hospital between 1997 and 2008 were retrieved. All isolates were classified using PFGE and underwent susceptibility testing f...

BACKGROUND We investigated the species distribution and amphotericin B (AMB) susceptibility of Korean clinical Aspergillus isolates by using two Etests and the CLSI broth microdilution method. METHODS A total of 136 Aspergillus isolates obtained from 11 university hospitals were identified by sequencing the internal transcribed spacer (ITS) and β-tubulin genomic regions. Minimal inhibitory co...

We determined the patterns of antimicrobial susceptibility of 65 isolates of Bacillus anthracis (50 historical and 15 recent U.S. clinical isolates) to nine antimicrobial agents using the National Committee for Clinical Laboratory Standards (NCCLS) broth microdilution reference method. The results for the 50 historical B. anthracis isolates obtained by the broth microdilution method were compar...

OBJECTIVES The aim of the present study was to evaluate the effects of amphotericin B (AMB) on clinical isolates of Aspergillus flavus. METHODS MICs of both standard AMB and liposomal AMB (L-AMB) were determined using a broth dilution method for seven isolates of A. flavus. AMB MICs were also determined using the Etest. The activity of the polyene was then investigated in a murine model of sy...

OBJECTIVES To determine the antibiotic susceptibility patterns of 60 strains of Laribacter hongkongensis isolated from humans and fish to eight antibiotics and compare the results obtained from broth microdilution, Etest and disc diffusion susceptibility testing. PATIENTS AND METHODS The susceptibilities of 60 isolates of L. hongkongensis from humans with gastroenteritis and fish to eight ant...

A novel formulation of RPMI 1640 medium for susceptibility testing of Malassezia yeasts by broth microdilution (BMD) and Etest is proposed. A modification of the NCCLS M27-A2 BMD method was used to test 53 isolates of Malassezia furfur (12 isolates), M. sympodialis (8 isolates), M. slooffiae (4 isolates), M. globosa (22 isolates), M. obtusa (2 isolates), M. restricta (2 isolates), M. pachyderma...

OBJECTIVE To study susceptibility of clinical isolates of multi-drug resistant (MDR) Gram-negative bacilli to colistin by minimum inhibitory concentration (MIC) determination using Etest, and compare this with their susceptibility measured by the disc diffusion (DD) method. METHODS A total of 224 of MDR organisms (147 Acinetobacter baumannii [A. baumannii], 49 Acinetobacter species, 24 Stenot...

BACKGROUND Therapy for Helicobacter pylori is generally empiric despite the fact that resistance to metronidazole and clarithromycin compromise therapeutic efficacy. The aim of this study was to aid clinicians in choosing a course of therapy for H pylori infection in the United States. METHODS The frequency of primary clarithromycin and metronidazole resistance among H pylori isolated from pa...