In vitro activities of 22 antimicrobial agents against Listeria monocytogenes strains isolated in Barcelona, Spain

The in vitro activity of 22 antimicrobial agents against 82 human Listeria monocytogenes strains isolated in Barcelona from 1994 to 1998 was determine d. Ampicillin and gentamicin showed good in vitro activity against all stra ins (MIC90: 1 and less than or equal to0.25 mug/ml, respectively). No resis tance to rifampin or co-trimoxazole was detected and only one strain was re sistant to tetracycline. Of the nine fluoroquinolones tested, clinafloxacin and gemifloxacin were the most active compounds (MIC90: 0.12 and 0.25 mug/ ml, respectively). No increasing MICs values were observed during the five- year period. (C) 2000 Elsevier Science Inc. All rights reserved.