In vitro susceptibility of Arcobacter butzleri and Arcobacter cryaerophilus to different antimicrobial agents.

Seventeen strains of Arcobacter butzleri and thirteen of Arcobacter cryaerophilus, were tested for their antimicrobial susceptibility to 26 antimicrobial agents. Among beta-lactams agents in this study, imipenem was the most active agent against both A. butzleri and A. cryaerophilus isolates with MIC(90) values of 2 and 4 mg/l, respectively. The most active cephalosporin tested was cefepime, although it was more active against A. butzleri (MIC(90) 8 mg/l) than A. cryaerophilus (MIC(90) 64 mg/l). Levofloxacin, marbofloxacin, enrofloxacin and ciprofloxacin were the best-performing fluoroquinolones against these species. Of the aminoglycosides, amikacin was the most active agent against both A. butzleri and A. cryaerophilus strains with MIC(90) values of 64 and 16 mg/l, respectively. All isolates showed high levels of resistance to penicillins, macrolides, chloramphenicol, trimethoprim and vancomycin.