Peritonitis caused by Bifidobacterium longum: case report and literature review.

Bifidobacterium spp. rarely causes human infections. We report a case of a 42-year-old man with a history of pancolonic diverticulosis, who suffered a purulent peritonitis caused by Bifidobacterium longum secondary to intestinal perforation. Clinical outcome was good after urgent surgery and antibiotic treatment with imipenem and amoxicillin/clavulanic acid. Our case shows that Bifidobacterium spp. should be considered as a cause of peritonitis, especially in patients with risk of intestinal perforation. The review of the literature shows that these organisms can cause a wide spectrum of severe infections, especially in patients with underlying diseases. Infections caused by Bifidobacterium spp. may be overlooked or underreported since it may be considered normal microbiota.