Density-dependent resistance protects Legionella pneumophila from its own antimicrobial metabolite, HGA.

ABSTRACT: To persist in microbial communities, the bacterial pathogen Legionella pneumophila must withstand competition from neighboring bacteria. Here, we find that L. pneumophila can antagonize the growth of other Legionella species using a secreted inhibitor: HGA (homogentisic acid). Unexpectedly, L. pneumophila can itself be inhibited by HGA secreted from neighboring, isogenic strains. Our genetic approaches further identify lpg1681 as a gene that modulates L. pneumophila susceptibility to HGA. We find that L. pneumophila sensitivity to HGA is density-dependent and cell intrinsic. Resistance is not mediated by the stringent response nor the previously described Legionella quorum-sensing pathway. Instead, L. pneumophila cells secrete

SUBMITTER: Levin TC 

PROVIDER: S-EPMC6598767 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature