The issue of extended–spectrum beta-lactamase (ESBL) production is one of the most serious problem for control of various bacterial infection disease through the world. This study was conducted to find out thetrend of characteristics of ESBL-producing Escherichia coli isolates at tertiary care university hospital in the central region of Japan from 2008 to 2010. Escherichia coli was identified by standard laboratory procedure. Antibacterial susceptibility testing was performed by micro dilution assay according to CLSI recommendation and isolates showing in vitro resistance to ceftazidime or cefotaximewere classified as ESBL-producing organism. Two hundred six Escherichia coli isolations were determined as ESBL-producing bacteria for three years. One hundred nine bacteria were isolated from female. The majority of age incidence were from sixty to eighty years age group. One hundred two isolates were from inpatient. The major source of isolates were urine and positive samples were received mostly from the urology. ESBL phenotype showed that cefotaxime-resistant isolates were greater than ceftazidime-resistant isolates.There were significant differences of trend of gender and the third cephalosporin resistant rates between 2008 and 2010. The continuous surveillance of ESBL-producing Escherichia coli is needed for treatment of Escherichia coli infectious disease.
