Phylogenetic analysis of bacterial community in the gut of American cockroach (Periplaneta americana).

OBJECTIVE

The present study was to fully evaluate the intestinal bacterial community of Periplaneta americana, an important model to study insects.

METHODS

We investigated the bacterial community of P. americana gut by culture-independent methods, involving constructing the 16S rRNA gene library and microbial diversity analysis.

RESULTS

The phylotypes were affiliated with Proteobacteria (66.4%), Bacteroidetes (17.8%), Firmicutes (14.5%), Fusobacteria (0.6%) and unclassified bacteria (0.6%). Phylogenetic analysis shows that 15% of the sequences clustered with that from a closely related omnivorous cockroach; and 59% clustered with that from more distantly related animals, including omnivorous, herbivorous, and carnivorous animals, which differ greatly in feeding habits. Moreover, 18% of the clones showed high sequence identity with potential pathogens closely related to human diseases, which also reinforces the concept of the cockroach as a carrier of pathogens.

CONCLUSION

Due to their habits of feeding on a variety of foodstuffs, omnivorous cockroaches harbor a large and diverse microbial community in the gut. The host phylogeny and dietary habits might be critical for the intestinal bacterial community composition of cockroaches.