Murine model for therapy of listeriosis in the compromised host. IV. Cotrimoxazole.

Mice infected with a cotrimoxazole-susceptible strain of Listeria monocytogenes (MIC 0.25 mg/l) were highly protected by a short-lived therapy with this drug. The excellent activity of ampicillin, however, was not achieved. Only the combination of trimethoprim and sulfamethoxazole gave sufficient protection. In dextran sulfate-treated mice, highly susceptible to listeria infection, cotrimoxazole showed also good activity. In the nude, athymic mouse, however, when the deficient immune system did not afford assistance to the elimination of bacteria, only transient reduction of bacterial counts occurred.