Antibiotic sensitivity of 139 strains of Listeria serotyped by the National Reference Center in 1983

The susceptibility of 139 strains of Listeria towards eight antibiotics--penicillin, ampicillin, cephalotin, gentamicin, chloramphenicol, tetracycline, erythromycin and pefloxacin--was studied. All strains were susceptible to all antibiotics except pefloxacin. The lowest MIC (less than or equal to 0.5 mg/l) were obtained with penicillin, ampicillin, gentamicin and erythromycin. For tetracycline, cephalotin and chloramphenicol, MIC ranged from 0.5 to 16 mg/l. The MIC of pefloxacin varied from 4 to 16 mg/l.