Mendes, C.¹*, Mimica, I.², Sampaio, J.³ and Ferreira, M.C.⁴.
Divisão de Moléstias Infecciosas e Parasitárias (LIM 54) Universidade de São Paulo¹, Santa Casa de São Paulo², Laboratório Lâmina, Rio de Janeiro³ and Universidade Federal do Rio de Janeiro⁴, Brazil.

The in vitro antibacterial activity of meropenem and other five antimicrobials (imipenem, metronidazol, clindamycin, cloramphenicol and cefoxitin) was compared in studies at 4 Brazilian centers in 1997. Meropenem is a parenteral carbapenem antimicrobial with an extended spectrum of in vitro activity against a wide range of Gram positive and Gram negative aerobes and anaerobes. With use of standardized and controlled procedures to determine the minimal inhibitory concentrations (MICs) using the E test methodology 161 recent clinical anaerobic isolates consisting of 10 different species were tested. Meropenem and imipenem showed the lowest MIC₉₀ for all the 10 species tested. For Bacteroides fragilis the MIC₉₀ for meropenem and imipenem was 0.38 and 0.5 µg/mL respectively. Overall, carbapenems were the most active drugs. All the strains tested showed the same percentage of resistance to both carbapenems (3,1%) and the isolates were equally less frequently resistant to cefoxitin (7,5%) than to chloramphenicol (10,6%), clindamycin (25,5%) and metronidazol (27,6%). A high degree of antimicrobial activity of meropenem and imipenem was confirmed at all 4 Brazilian centers. These data suggest that meropenem and imipenem may represent effective alternative empirical therapy for patients with anaerobic infections.