Respiratory tract pathogens isolated from patients hospitalized with suspected pneumonia in Latin America: frequency of occurrence and antimicrobial susceptibility profile: results from the SENTRY Antimicrobial Surveillance Program (1997-2000)

In spite of the recent medical advances, lower respiratory tract infections are still the most frequent infectious causes of mortality worldwide. The objective of this study was to determine the frequency of occurrence and antimicrobial susceptibility of bacterial isolates collected from hospitalized patients with pneumonia in Latin American medical centers during the first four years of the SENTRY Program. The five most frequently isolated species were (n/%): Pseudomonas aeruginosa (659/26.3%), Staphylococcus aureus (582/23.3%), Klebsiella pneumoniae (255/10.2%), Acinetobacter spp. (239/9.6%), and Enterobacter spp. (134/5.4%). P. aeruginosa demonstrated high rates of resistance to most of the antimicrobials tested. Against P. aeruginosa, the most active agents were meropenem (MIC(50), 1 microg/ml; 71.6% susceptible), amikacin (MIC(50), 4 microg/ml; 71.0% susceptible), and piperacillin/tazobactam (MIC(50), 16 microg/ml; 70.4% susceptible). Imipenem (MIC(50), 1 microg/ml; 84.1% susceptible) and meropenem (MIC(50), 2 microg/ml; 84.9% susceptible) were the most active agents against Acinetobacter spp. followed by tetracycline (MIC(50),