Guo, L., J. S. McLean, Y. Yang, R. Eckert, C. W. Kaplan, P. Kyme, O. Sheikh, B. Varnum, R. Lux, W. Shi and X. He (2015). “Precision-guided antimicrobial peptide as a targeted modulator of human microbial ecology.” PNAS. published ahead of print June 1, 2015, doi:10.1073/pnas.1506207112 OPEN ACCESS
Targeting individual species in oral microbial communities
The lack of tools to target individual species has made it difficult to determine their specific contributions within a complex microbial community. Lihong Guo et al. report that a targeted antimicrobial peptide called C16G2 selectively killed the pathogen Streptococcus mutans within an oral multispecies community derived from saliva. S. mutans is one of the causative agents of tooth decay worldwide, and using broad spectrum antibiotics to treat the pathogen results in the loss of the entire oral bacterial community, often leading to reinfection by S. mutans. C16G2 treatment caused a significant change in the overall structure of the microbial community and in the relative amounts of different Streptococcus species. Removal of S. mutans from the community reduced the abundance of bacterial species that had direct physical interactions with the pathogen and increased the abundance of various other Streptococcus species that are highly prevalent in healthy oral cavities. The authors suggest that C16G2 may have therapeutic potential to remove pathogenic S. mutans and help achieve a healthy oral microbiome. The study demonstrates the ability of targeted antimicrobials to modulate microbiome structure and investigate the community role of bacterial species, according to the authors. — S.R.