NOTES Activity of Meropenem against Antibiotic-Resistant or Infrequently Encountered Gram-Negative Bacilli

Meropenem was compared in vitro with imipenem as well as with several other contemporary beta-lactams, ciprofloxacin, and gentamicin against a group of highly antibiotic resistant members of the family Enterobac-teriaceae and a collection of oxidase-positive and/or glucose-nonfermentative gram-negative bacilli. In this study, meropenem was more active than imipenem against isolates of Enterobacter, Klebsiella, Morganella, Providencia, Alcaligenes, Aeromonas, and Pasteurella. Meropenem (SM-7338) is an investigational carbapenem antibiotic with greater potency than imipenem against some gram-negative bacilli (2, 3, 5) and with greater stability to renal dehydropeptidase activity (1, 8). In the present study, we sought to evaluate the activities of meropenem, imi-penem, and several additional beta-lactam antibiotics, cip-rofloxacin, and gentamicin against a group of antibiotic-resistant or infrequently encountered gram-negative bacilli. Bacterial test strains of clinical origin were selected for this investigation because they demonstrated resistance t