Isolation and identification of Bifidobacterium species from feces of captive chimpanzees

Recently, gut-dwelling bifidobacteria from chimpanzees, which are phylogenetically close to humans and have feeding habits similar to humans, have been frequently investigated. Given this, we speculated that like humans, chimpanzees would have a unique diversity of bifidobacteria. We herein describe a taxonomically novel member of bifidobacteria isolated from fecal samples of captive chimpanzees. Bifidobacteria were detected in all fecal samples by quantitative polymerase chain reaction. A Bifidobacterium pseudolongum-like species, which could not be detected using B. pseudolongum-specific primers targeting the groEL gene sequence, was dominant in the feces of five chimpanzees. Seven bifidobacterial strains were isolated from this group of five chimpanzees, and all isolates were identified as B. pseudolongum. B. pseudolongum has previously often been isolated from non-primate animals as well as humans; however, here we demonstrate its presence in a nonhuman primate species.

A cautionary note on fecal sampling and molecular epidemiology in predatory wild great apes

Fecal samples are an important source of information on parasites (viruses, prokaryotes, or eukaryotes) infecting wild great apes. Molecular analysis of fecal samples has already been used for deciphering the origins of major human pathogens such as HIV-1 or Plasmodium falciparum. However, for apes that hunt (chimpanzees and bonobos), detection of parasite nucleic acids may reflect either true infection of the host of interest or ingestion of an infected prey, for example, another non-human primate. To determine the potential magnitude of this issue, we estimated the prevalence of prey DNA in fecal samples obtained from two wild chimpanzee communities. We observed values >15%, which are higher than or close to the fecal detection rates of many great ape parasites. Contamination of fecal samples with parasite DNA from dietary origin may therefore occasionally impact non-invasive epidemiological studies. This problem can be addressed (at least partially) by monitoring the presence of prey DNA.