We recently read an article on carbapenem susceptibility testing errors in studies that used three automated systems, disk diffusion (DD), Etest (ET), and broth microdilution (BMD), to investigate Acinetobacter baumannii-calcoaceticus complex (ABC) isolates (1). The authors concluded from the study that the manual methods are more accurate than automated methods. The error rates for testing sus...

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...

Inhaled administration of tobramycin assures high concentrations in cystic fibrotic lungs, improving the therapeutic ratio over that of parenteral tobramycin levels, particularly against Pseudomonas aeruginosa. Conventional Clinical and Laboratory Standards Institute (CLSI; formerly National Committee for Clinical Laboratory Standards) breakpoints only consider parenteral levels and do not take...

A multicenter study was conducted to validate Etest tigecycline compared to the Clinical Laboratory Standards Institute reference broth microdilution and agar dilution methodologies. A large collection of gram-negative (n = 266) and gram-positive (n = 162) aerobic bacteria, a collection of anaerobes (n = 385), and selected collections of nonpneumococcal streptococci (n = 369), Streptococcus pne...

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...

The susceptibility of 513 clinical isolates to doripenem was determined by broth microdilution, agar dilution, and Etest. Overall agreements for Etest and agar dilution MIC values compared to reference broth microdilution at +/-1 log(2) dilution were 88% and 94%, respectively. Etest MIC values demonstrated 98% agreement within +/-2 log(2) dilutions compared to the reference broth microdilution ...

The MIC(50) and MIC(90) values of doripenem, determined by Etest, for 110 isolates of Burkholderia pseudomallei were 0.5 and 0.75 microg/ml, respectively. There were significant correlations between MICs determined by Etest and MICs determined by agar dilution, MICs determined by Etest and inhibition zone size, and MICs determined by agar dilution and inhibition zone size.

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...

The disk approximation method, Etest (AB Biodisk, Solna, Sweden), and VITEK 2 system (bioMérieux, Marcy l’Etoile, France) were used to study 399 extended-spectrum h-lactamase (ESBL)-producing (115 strains) and non-ESBL-producing (284 strains) clinical isolates of Escherichia coli after recommended procedures. Comparative study of the phenotypic findings yielded data on the sensitivity, specific...

BACKGROUND Enterobacteriaceae producing ESBL and AmpC enzymes can be associated with failure of antibiotic therapy and related morbidity and mortality. Their routine detection in microbiology laboratories is still a problem. The aim of this study was to compare the sensitivity of selected phenotypic methods. MATERIAL/METHODS A total of 106 strains of the Enterobacteriaceae family were tested,...