Compositions having synergistic effective amounts of one or more antibacterial agents, a nitroimidazole, and/or a sulfonamide or a molecule or compound having folic acid antagonist effect and nitroimidazole substitution in addition, with or without an antifungal agent effective against a Candida species. The compositions are particularly useful in the treatment of genitourinary infections and their extragenital complications. Vaccination against pathogen microbes of the vagina provides a stronger and longer immune response, then the infection.