Antibiotic susceptibility of five strains of Listeria monocytogenes

The susceptibily to four antibiotics of five strains of Listeria monocytogenes was investigated by MIC - determination [Broth dilution method]. Ampicillin and erythromycin demonstrated the lowest MICs. High MIC of tetracycline was observed. There was no significant difference according to serovarieties. The combination of tetracycline and septran was synergistic. While the other two combinations showed an additive effect