Long-term study of Escherichia coli and Klebsiella pneumoniae isolates producing extended-spectrum beta-lactamases

To evaluate the prevalence and susceptibility pattern of Escherichia coli and Klebsiella pneumoniae isolates producing extended-spectrum beta-lactamases (ESBLs) in Thailand from 2000 to 2005. Data on the WHONET, from 28 hospitals participated in the National Antimicrobial Resistance Surveillance, Thailand surveillance program, were reviewed and analyzed for the prevalence and susceptibility pattern. During the five-year surveillance from 2000 to 2005, the prevalence of ESBL-producing E. coli detected by ceftazidime screening test was 17%, 21.3%, 23.2%, 20.4%, 23.1%, and 25.0%; as well as detected by cefotaxime screening test was 20.8%, 65.9%, 69.3%, 69.3%, 68.3%, and 33.8%, respectively. The prevalence of ESBL-producing K. pneumoniae detected by ceftazidime screening test was 30.9%, 34.7%, 32.5%, 34.4%, 372%, and 39.2%; as well as detected by cefotaxime screening test 38.4%, 39.3%, 40.1%, 41.0%, 42.8%, and 40.4%, respectively. From 2000 to 2005, the prevalence of ESBL-producing organisms in Thailand was high. ESBL-producing E. coli was most commonly isolated from sputum, followed by blood and urine specimens. ESBL-producing K. pneumoniae had not been increasingly isolated from sputum, blood and urine.