Antimicrobial susceptibility of aerobic microorganisms isolated from intraabdominal infections in pediatric patients in Poland.

Background: Growing resistance to antibiotics among both community-acquired and hospital pathogens is making the treatment of most infections increasingly difficult. Therefore, the aim of our multi-center study was to determine the antimicrobial susceptibility of the most frequent aerobic microorganisms isolated from children with intraabdominal infections.

Material/methods: Bacterial pathogens were isolated from 256 consecutive patients treated in five large specialized hospitals in Poland from January 2001 to February 2002. Minimal inhibitory concentrations (MICs) of piperacillin, piperacillin-tazobactam, cefotaxime, ceftazidime and cefepime were determined by Etests. The production of extended spectrum beta-lactamases (ESBL) was detected by a double-disk test.

Results: Piperacillin-tazobactam was the most active agent against Enterobacteriaceae and Pseudomonas aeruginosa, inhibiting 92% and 78% of isolates respectively. Susceptibility of Enterobacteriaceae to cefotaxime, ceftazidime and cefepime was 73%, 73% and 87% respectively, and susceptibility of P. aeruginosa to both ceftazidime and cefepime was 76%. Extended-spectrum beta-lactamases were detected in 56% Klebsiella sp. and 11.5% E. coli, but the vast majority of these isolates remained susceptible to piperacillin-tazobactam (MIC(90) = 12 mg/L and MIC(90) = 1 mg/L, respectively).

Conclusions: Piperacillin/tazobactam remains a valuable therapeutic option in Polish pediatric patients with intraabdominal infections, due to its good activity against ESbetaL-producing organisms and P. aeruginosa.