Pulmonary Infection Status, Drug-resistance and Risk Factors of Extended-spectrum β-Lactamases-producing Bacteria

OBJECTIVE To survey the patient with pulmonary infection induced by extended-spectrum β-lactamases-producing bacteria and their Enterobacteriaceae clinical characteristics, drug-resistance and countermeasure. METHODS Isolation, cultivation, identification, drug-sensitivity tests and confirmation of ESBLs-producing bacteria were done for the bacteria of sputum specimens collected from our hospital from Feb 2001 to Sept 2004. Susceptibility testing was performed by disk diffusion(K-B)method. RESULTS Totally 541 strains of Enterobacteriaceae were cultivated altogether and ESBLs-producing bacteria were 135 strains. The ESBLs- producing strains were sensitive to imipenem, and the resistance rates to it were 0.00% . The resistance rates of ESBLs-producing strains to cefoperazone/sulbactam and piperacillin/tazobactam were 31.11% and 44.44%, respectively . The multi-drug-resistance (MDR) rate of ESBLs-producing strains was higher than that of strains no producing ESBLs (P0.01). Totally 6 risk factors such as ICU ward, invasive medical manipulations, use of the third generation cephalosporins, etc were determined. CONCLUSIONS The prevalence of ESBLs from Enterobacteriaceae is high in clinical isolates from pulmonary infection patients. The resistant rates of ESBLs- producing strains to most antibiotics are higher than non-ESBLs-producing ones. Imipenem is the most effective antibiotic to infections caused by ESBLs-producing strains and several risk factors are existed in ESBLs-producing strains. We should pay more attemtion to ESBLs in clinics.