Evaluation of gentamicin and penicillin as a synergistic combination in experimental murine listeriosis.

The administration of a combination of penicillin and gentamicin to mice given an intraperitoneal challenge of a highly pathogenic strain of Listeria monocytogenes resulted in increased survival as compared with groups receiving penicillin alone or gentamicin alone or a control group that received no antibiotic. The median survival of animals that eventually died was no longer than in groups receiving single antibiotics and suggests that additional studies should be carried out to further investigate the possibility of synergism in animal models.