Antibiotic Resistance Trends and The ESBL Prevalence of Escherichia coli and Klebsiella spp Urinary Isolates in In-and Outpatients in a Tertiary Care Hospital in Istanbul, 2004 - 2012

Background Extended spectrum beta-lactamase (ESBL) producing organisms causing urinary tract infections are increasing in incidence and becoming a serious health problem due to their resistance to large number of antibiotics. Objectives To investigate the ESBL prevalence of Escherichia coli and Klebsiella spp. which are isolated from urine samples for both in and outpatients with their resistance profiles. Methods From 2004 to 2012, a total of 13975 isolates (12897 E. coli, 1078 Klebsiella spp.) were included in this study. The antibiotic susceptibility was tested using Kirby–Bauer disk diffusion method and Vitek2 System (bioMerieux, France) according to CLSI. Results Our data showed a significant increasing in ESBL prevalence from 12.5% to 44.7% (P < 0.001) for inpatients; from 9.6% to 22.8% (P < 0.001) for outpatients in E. coli and from 25% to 60.5% (P < 0.003) for inpatients; from 12% to 25% (P < 0.095) for outpatients in Klebsiella spp. For E. coli, the increase was significantly high in both of males and females (P < 0.001). However, for Klebsiella spp. it was significantly high in male patients (P < 0.001). The resistance rates of antibiotics for the ESBL producing E. coli, and Klebsiella spp. showed a significant increase. These rates were higher than 70% for fluoroquinolones, amoxicillin-clavulanic acid and trimethoprim-sulfamethoxazole. Even carbepenem resistance reached to 7% in the outpatients and 15% in inpatients for ESBL producing Klebsiella spp. Conclusions Our study demonstrated a significant increase in the prevalence of ESBL producing E. coli and Klebsiella spp. and a remarkable carbapenem resistance trend in the ESBL producing Klebsiella spp. isolated from urine samples.