Enteric flora of normal laboratory guinea-pigs.

The bowel flora of guinea-pigs was studied using non-selective cultural conditions and conditions highly selective for Escherichia coli organisma. No E. coli were cultured from adult or juvenile bowel content. Parallel studies showed that culture media supported the growth of small numbers of reference E. coli "seeded" into them along with bowel content. It is concluded that normal adult laboratory guinea-pigs may be bacteriologically equivalent to the NCS strain of "E. coli-free" mice.