Therapy of experimental listeriosis--an evaluation of different antibiotics.

The therapeutic activities of various antibiotics were evaluated in two murine models, i.e. the infection of normal mice as well as of nude mice. Coumermycin and rifampicin were the most active drugs, since not only inhibition of multiplication but also rapid elimination of Listeria monocytogenes could be achieved in normal and immunocompromised animals. Ampicillin was the most active beta-lactam antibiotic followed by azlocillin. The other beta-lactam antibiotics were definitely less active. The combination of ampicillin with gentamicin expressed no synergistic effect in vivo. Co-trimoxazole as well as ciprofloxacin were of moderate therapeutic value. The bacteriostatic drugs such as tetracycline and erythromycin were able to inhibit the bacterial multiplication in the normal mouse but not in the immunocompromised host. Thus an optimal drug for therapy of listeriosis does not yet exist.