The Gram-positive Non-spore-bearing Anaerobic Bacilli of Human Feces

Abstract

Anaeroic plate cultures of 85 stools yielded 130 strains (11 species) of Gram-positive non-spore-bearing anaerobic bacilli. These were provisionally placed in the genus Bacteroides. They are: B. lentus, B. ventriosus, B. aerojaciens, B. biformis, B. tortuosus, B. catenaformis, B. pseudoramosus, B. avidus, B. limosus, B. cornutus, and B. bifidus. The B. bifidus from adult stools were found to differ in their sugar fermentation reactions from the B. bifidus from the stools of infants. These 11 spp. seem sufficiently closely related to be included in 1 genus. As they differ in many respects from Bacteroides, it is suggested that they be classified either in Lactobacillus or in a separate genus.