Etest is a new concept for MIC determinations for antimicrobial agents that is based on a predefined antibiotic gradient on a plastic strip calibrated with a continuous logarithmic MIC scale covering 15 twofold dilutions. Etest was compared with a reference agar dilution method for susceptibility testing of clinical isolates of Mycobacterium chelonae and M. fortuitum. Results read after 3 days ...

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...

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...

Pan-drug-resistant (PDR) Acinetobacter baumannii is an important nosocomial pathogen that poses therapeutic challenges. Tigecycline alone or in combination with agents such as colestimethate, imipenem, and/or amikacin is being used clinically to treat PDR A. baumannii infections. The purpose of this study was to compare in vitro susceptibility testing by epsilometric (Etest) methods and the che...

OBJECTIVES To evaluate four phenotypic tests for the detection of metallo-beta-lactamase (MBL) production in Pseudomonas aeruginosa in a low MBL prevalence setting. METHODS Sixty clinical isolates of P. aeruginosa resistant to imipenem and/or meropenem and seven MBL-positive control strains were examined by: (i) MBL Etest; (ii) combined imipenem discs supplemented with EDTA (IPM-EDTA); (iii) ...

BACKGROUND Antimicrobial-resistant Neisseria gonorrhoeae is a major public health threat. Current CDC treatment guidelines for uncomplicated gonorrhoea recommend only ceftriaxone plus either azithromycin or doxycycline. Additional treatment options are needed. METHODS We used antibiotic gradient synergy testing (the Etest) to evaluate antimicrobial combinations that included a third-generatio...

Due to the rise in methicillin-resistant Staphylococcus aureus (MRSA) infections and widespread use of vancomycin, MRSA isolates with reduced susceptibility to vancomycin are emerging (i.e., MIC creep). However, the prevalence of heterogeneous vancomycin-intermediate S. aureus (hVISA) is unknown due to the difficulty in detecting this phenotype. Recently, Etest glycopeptide resistance detection...

TO THE EDITOR— The recent publication by Pickering et al [1] described a collection of methicillin-susceptible Staphylococcus aureus (MSSA) that displayed elevated ceftriaxone minimum inhibitory concentrations (MICs) when tested by Etest (bioMerieux, Durham, North Carolina) gradient diffusion and would have been called “Resistant” to ceftriaxone based on previous Clinical and Laboratory Standar...

OBJECTIVES To assess the relevance of vancomycin-intermediate susceptibility (VISA) and heteroresistance (hVISA) in methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia. METHODS We determined vancomycin MICs for 371 saved MRSA blood isolates (2002-03; 2005-06) by Etest and broth microdilution (BMD), screened for hVISA (Etest methods), determined the population analysis profile (PAP)...

The sensitivity and specificity of seven methods (agar dilution, broth microdilution, Etest at 0.5 and 2.0 McFarland (McF) inocula, two agar screening methods, and population studies [PS]) were evaluated in a double-blind study involving 284 methicillin-resistant Staphylococcus aureus (MRSA) strains and 45 Staphylococcus strains with reduced susceptibilities to vancomycin (SRSV). The results we...