Therapeutic activities of antibiotics in listeriosis.

In vitro practically all common antibiotics except cephalosporins are active against nearly all natural isolates of Listeria monocytogenes; the therapeutic efficacy of antibiotic treatment is, however, rather limited, since up to 30% listeriosis patients will succumb to this infection. At least one reason for this low in vivo efficiency is the intracellular habitat of L. monocytogenes. In animal experiments ampicillin or amoxicillin, respectively, are still the most active drugs. In addition, rifampicin also has pronounced protective activity. Coumermycin, which unfortunately cannot be given to humans, is the most reliable drug in animals.