In vitro and in vivo activities of meropenem and comparable antimicrobial agents against Haemophilus influenzae, including beta-lactamase-negative ampicillin-resistant strains.
The in vitro activity of ampicillin, cefotaxime, meropenem, panipenem, imipenem and biapenem was assayed using ampicillin-susceptible, beta-lactamase-positive and beta-lactamase-negative ampicillin-resistant (BLNAR) Haemophilus influenzae isolated recently in Japan. Against ampicillin-susceptible isolates, cefotaxime was the most potent (MIC(90) 0.016 mg/mL). Both cefotaxime and meropenem (MIC(90) of both, 0.5 mg/L) were the most potent against beta-lactamase-positive isolates. Against BLNAR isolates, meropenem (MIC(90) 0.5 mg/L) was the most potent. In murine bronchopneumonia caused by ampicillin-susceptible and BLNAR H. influenzae, cefotaxime showed the best efficacy, followed by meropenem. Our results indicate that meropenem could be a useful intravenous agent for infections caused by H. influenzae, including BLNAR strains.
Miyazaki
S
S
Department of Microbiology, Toho University School of Medicine, 5-21-16 Omori-nishi, Ota-ku, Tokyo143-8540, Japan. shuichi@med.toho-u.ac.jp
Fujikawa
T
T
Kanazawa
K
K
Yamaguchi
K
K
D000668:Ampicillin Resistance; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001996:Bronchopneumonia / Q000188:drug therapy / Q000201:enzymology / Q000382:microbiology; D006192:Haemophilus Infections / Q000188:drug therapy / Q000201:enzymology / Q000382:microbiology; D006193:Haemophilus influenzae / Q000187:drug effects* / Q000201:enzymology / Q000302:isolation & purification; D006801:Humans; D000077731:Meropenem; D051379:Mice; D013845:Thienamycins / Q000494:pharmacology* / Q000627:therapeutic use; D001618:beta-Lactamases / Q000302:isolation & purification
D000900:Anti-Bacterial Agents; D013845:Thienamycins; D001618:beta-Lactamases; D000077731:Meropenem