Hoşoğlu, SGündes, SKolayli, FKaradenizli, ADemirdağ, KGünaydin, MAltindis, MCaylan, RUcmak, H2007-10-192009-05-282007-10-192009-05-282007-10-19Hoşoğlu S, Gündes S, Kolayli F, Karadenizli A, Demirdağ K, Günaydin M, Altindis M, Caylan R, Ucmak H. Extended-spectrum beta-lactamases in ceftazidime-resistant Escherichia coli and Klebsiella pneumoniae isolates in Turkish hospitals. Indian Journal of Medical Microbiology. 2007 Oct; 25(4): 346-50http://imsear.searo.who.int/handle/123456789/53444PURPOSE: To study the prevalence of TEM-, SHV- and GES-type beta -lactamases among Escherichia coli and Klebsiella pneumoniae strains having ceftazidime MICs higher than 2 mg/L. METHODS: A total of 63 E. coli and 41 K. pneumoniae isolated from five different university hospitals were studied for the existence of TEM-, SHV- and GES-type beta -lactamases. Susceptibility tests were carried out according to the criteria of National Committee for Clinical Laboratory Standards. MICs were obtained by agar dilution method. Existence of extended-spectrum beta -lactamases (ESBLs) were assessed by double-disc synergy test (DDST). Existence of the above-mentioned beta -lactamase genes were studied both by PCR with specific oligonucleotide primers and isoelectric focusing methods. RESULTS: None of the isolates were carbapenem-resistant. DDSTs were positive in 50 (79.3%) and 33 (80.5%) of E. coli and K. pneumoniae , respectively. TEM gene was detected in 41 (65.1%) and 19 (46.3%), whereas SHV gene in 18 (28.6%) and 20 (48.8%) of E. coli and K. pneumoniae strains, respectively. GES genes were not detected. CONCLUSIONS: TEM and SHV genes are highly prevalent among ESBL-producing E. coli and K. pneumoniae , whereas GES-type ESBLs are absent and found not to be responsible of ceftazidime resistance in Turkish hospitals.engAnti-Bacterial Agents --pharmacologyBacterial Proteins --biosynthesisCarbapenems --pharmacologyCeftazidime --pharmacologyDNA, Bacterial --geneticsEscherichia coli --drug effectsEscherichia coli Infections --microbiologyHospitalsHumansKlebsiella Infections --microbiologyKlebsiella pneumoniae --drug effectsMicrobial Sensitivity TestsPolymerase Chain Reaction --methodsTurkeybeta-Lactam Resistancebeta-Lactamases --geneticsJournal Article