[Chemotherapy of listeriosis (author's transl)].

Despite the occasional lack of antibacterial activity ampicillin is considered to be the drug of choice for antibacterial chemotherapy in listeriosis. In vitro comparison with new penicillins (mezlocillin, piperacillin) and cephalosporins (cefamandol, cefoxitin, cefuroxime, cefotaxime) showed ampicillin to have the most potent activity against Listeria monocytogenes. Minimal inhibition concentrations (MIC) were between 0.06 and 1 microgram/ml and minimal bactericidal concentrations (MBC) from 0.25 to 32 micrograms/ml. The MIC90 (minimal concentration inhibiting 90% of tested strains) was 0.48 for ampicillin, 8.0 for mezlocillin and 5.2 micrograms/ml for piperacillin. Among cephalosporins cefalotin was most effective with an MIC90 of 5.8 micrograms/ml. The MIC90 was 7.8 for cefamandol and 89.6 micrograms/ml for cefoxitin. Cefuroxime and ecfotoxime had MIC values of more than 128 micrograms/ml and showed no clinically relevant anti-listeria activity. Gentamicin and doxycyclin showed MIC90 values of 12 and 8 micrograms/ml, respectively. MBC and MIC values were closest together in gentamicin. Ampicillin, potentially combined with gentamicin, should remain treatment of choice in generalised Listeria monocytogenes infection.