Clinical Microbiology and Antimicrobial Chemotherapy. 2009; 11(4):348-355
To investigate the etiology and antimicrobial resistance patterns of aerobic bacterial pathogens in community- and hospital-acquired intra-abdominal infections (IAI) in the ICUs of two teaching hospitals in one particular city.
A total of 168 patients with peritonitis (122 community-acquired, 46 nosocomial) were included in the study. Susceptibility testing was performed by agar dilution method according to CLSI recommendations.
Clinically significant aerobic pathogens were isolated in 61.5% (75⁄122) of patients with community-acquired and in 89% (41⁄46) of patients with hospital-acquired peritonitis. The most commonly detected pathogens in both groups were the members of Enterobacteriaceae family. The isolation rates of nonfermenting Gram-negative bacteria (P. aeruginosa and Acinetobacter spp.) and S. aureus were higher in patients with nosocomial peritonitis. Susceptibility of Gram-negative bacteria to all antimicrobials tested was significantly higher than in community-acquired strains. The most in vitro active against Gram-negative pathogens were carbapenems. Of 9 S. aureus strains isolated in nosocomial peritonitis, 8 were MRSA. All Gram-positive pathogens remain susceptible to vancomycin.
Based on the results of our study, potentially the most active therapy regimens for nosocomial peritonitis was the combination of carbapenems with vancomycin, and for community-acquired peritonitis – monotherapy with carbapenems.