Comparison of E Test and Double Disk Diffusion Test for Detection of Extended Spectrum Beta-Lactamases

Beta-lactam susceptibilities and prevalence of ESBL-producing isolates among more than 5000 European Enterobacteriaceae isolates

“…As has been described for other parts of the world [17,18], regional variations in ESBL prevalence occur in Europe. Potential ESBL-phenotypes (MIC ≥2 mg/l for ceftriaxone, ceftazidime or aztreonam) among Klebsiella pneumoniae are much more prevalent in Latin America (45.5%) and the Western Pacific (24.6%) than in the U.S. and Canada (7.6% and 4.9%, respectively) [19].…”

“…ESBL-Etest and disk diffusion tests were performed and interpreted as recommended by the manufacturer and NCCLS [16]. ESBL-production was considered as confirmed if either the double disk diffusion test or the ESBL-Etest was positive [17].…”

Phenotypic detection and polymerase chain reaction screening of extended-spectrum β-lactamases produced by Pseudomonas aeruginosa isolates

“…15 Detection of ESBLs by DDST with clavulanic acid and extendedspectrum cephalosporins is sensitive and specific for the detection of ESBLs in the Enterobacteriaceae. 24,25 The Enterobacteriaceae with elevated MIC, positive screen test and positive confirmatory test may cause ESBL genes; while a negative ESBL confirmatory test, indicates the presence of ampC or a combination of ampC and ESBL in the Enterobacteriaceae. 7,26 Similarly, the DDST may not be sensitive enough for the detection of ESBLs in P. aeruginosa.…”

Unnoticed Spread of Integron-Carrying Enterobacteriaceae in Intensive Care Units

“…Susceptibility testing was performed by means of microdilution, according to NCCLS guidelines [10]. Extended-spectrum b-lactamase (ESBL) production was detected by means of the disk diffusion test and ESBL Etest [11]. Two isolates per species per patient (if available) were selected for detection and characterization of integrons.…”