Distribution and drug resistance of ESBLs-producing Escherichia coli and Klebsiella pneumonia in a hospital

Objective To study the distrubution and drug-resistance of Escherichia coli (E. coli) and Klebsiella pneumonia (K. pneumonia) which produced extended-spectrum beta-lactamases ( ESBLs) in a hospital. Methods The double-disk synergy test was performed to detect ESBLs-producing strains and antimicrobial susceptibility was determined by disk diffusion test in specimens collected from patients from October, 2007 to September, 2008. Results 443 of 766(57. 83%) E. coli strains produced ESBLs; 355 of 632 (56. 17%) K. pneumonia strains produced ESBLs. Most ESBLs-producing strains were isolated from sputum (557 strains, 69. 80%) and urine (149 strains, 18. 67%). ESBLs-producing strains were susceptible to imipenem/cilastatin, meropenem and cefoperazone/ sulbactam, but resistant to almost all the first to third generation cephalosporins, and had cross resistance among quinoiones and aminoglycosides. Conclusion Infections caused by ESBLs-producing strains are serious, majority are lower respiratory tract infection, the next is urinary tract infection; drug-resistance is high, imipenem/cilastatin, meropenem and cefoperazone/sulbactam have high antimicrobial activity on ESBLs-producing strains.