Comparative activity of meropenem (SM-7338) against major respiratory pathogens and amikacin-resistant nosocomial isolates.

Meropenem, a new broad-spectrum carbapenem antibiotic, demonstrated excellent in vitro activity against major respiratory pathogens including Moraxella catarrhalis, Haemophilus influenzae and Streptococcus pneumoniae. Minimal inhibitory concentrations of meropenem for Moraxella catarrhalis and Haemophilus influenzae isolates were frequently less than those of imipenem. For nosocomial amikacin-resistant gram-negative bacilli, meropenem had eightfold lower MIC90 values compared to imipenem against strains of Serratia marcescens, Enterobacter cloacae and Escherichia coli; it was 32-fold more active than imipenem against Proteus mirabilis isolates. Activity was similar to that of imipenem against Pseudomonas aeruginosa isolates. Overall, meropenem showed excellent activity against common community-acquired pathogens as well as amikacin-resistant nosocomial pathogens.