Study of intestinal microbial population shifts following brief administration of metronidazole and/or vancomycin in mice.

Metronidazole and vancomycin are the primary antibiotics used to treat infections with Clostridium difficile, a bacterium responsible for the majority of intestinal infections in hospitals. In addition, these antibiotics are increasing being prescribed as prophylaxis for patients at high risk for C. difficile infections. This study investigates the effect of brief (3 day) antibiotic administration on murine commensal bacterial species before and after infection with C. difficile. The propensity of the disordered microbiota to support C. difficile expansion in the lower intestine is examined.