BACKGROUND The development of hVISA has been associated with vancomycin clinical failures and is commonly misidentified in clinical microbiology laboratories. Therefore, the objectives of this present study was to improve the reliability of methodologies and criteria for identifying hVISA, evaluate the prevalence of hVISA among clinical bloodstream isolates of S. aureus and determine if there e...

Haemophilus influenzae is a major pathogen, and beta-lactams are first-line drugs. Resistance due to altered penicillin-binding protein 3 (rPBP3) is frequent, and susceptibility testing of such strains is challenging. A collection of 154 beta-lactamase-negative isolates with a large proportion of rPBP3 (67.5%) was used to evaluate and compare Etest (Haemophilus test medium [HTM]) and disk diffu...

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)...

BACKGROUND Increasing reports of carbapenem resistant Acinetobacter baumannii infections are of serious concern. Reliable susceptibility testing results remains a critical issue for the clinical outcome. Automated systems are increasingly used for species identification and susceptibility testing. This study was organized to evaluate the accuracies of three widely used automated susceptibility ...

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...

BACKGROUND AND PURPOSE The prevalence of extended-spectrum beta-lactamases (ESBLs) in Enterobacter cloacae remains unclear in Taiwan. This study was conducted to investigate the prevalence of ESBL-producing E. cloacae in Taiwan. METHODS 116 clinical isolates of E. cloacae were tested for cefepime susceptibility. Isolates with a minimal inhibitory concentration (MIC) of > or = 0.25 microg/mL f...

BACKGROUND A variety of techniques are available for antimicrobial susceptibility testing of Neisseria gonorrhoeae. OBJECTIVE The aim of this study was to find a cost-effective, reliable and easily applicable microbiological method to detect antimicrobial susceptibilities of N. gonorrhoeae in resource-poor countries. DESIGN Prospective study. SETTING Male and female STD clinic of Regional...

Korgenski and Daly recommend charcoal horse blood agar (Regan-Lowe agar) for the detection of erythromycin resistance in Bordetella pertussis by agar dilution, Etest methodology, or agar diffusion. MICs for most isolates were #0.06 to 0.12 mg/ml by agar dilution and the Etest, while the MIC for the only resistant strain was 16 to 64 mg/ml (4). Charcoal agar may be suitable for discrimination be...

In vitro activities of 17 antibiotics against 53 clinical strains of Mycobacterium marinum, an atypical mycobacterium responsible for cutaneous infections, were determined using the reference agar dilution method. Rifampin and rifabutin were the most active drugs (MICs at which 90% of the isolates tested were inhibited [MIC(90)s], 0.5 and 0.6 microgram/ml, respectively). MICs of minocycline (MI...

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,...