Affiliation:
1. Jiangsu Province Engineering Research Center for Marine Bio-resources Sustainable Utilization, College of Oceanography, Hohai University, Nanjing, Jiangsu, China
Abstract
ABSTRACT
Quorum sensing (QS) orchestrates many bacterial behaviors, including virulence and biofilm formation, across bacterial populations. Nevertheless, the underlying mechanism by which QS regulates capsular polysaccharide (CPS)-dependent phage-bacterium interactions remains unclear. In this study, we report that QS upregulates the expression of CPS-dependent phage receptors, thus increasing phage adsorption and infection rates in
Vibrio alginolyticus
. We found that QS upregulated the expression of the
ugd
gene, leading to increased synthesis of
Autographiviridae
phage receptor CPS synthesis in
V. alginolyticus
. The signal molecule autoinducer-2 released by
Vibrio
from different sources can potentially enhance CPS-dependent phage infections. Therefore, our data suggest that inhibiting QS may reduce, rather than improve, the therapeutic efficacy of CPS-specific phages.
IMPORTANCE
Phage resistance is a direct threat to phage therapy, and understanding phage-host interactions, especially how bacteria block phage infection, is essential for developing successful phage therapy. In the present study, we demonstrate for the first time that
Vibrio alginolyticus
uses quorum sensing (QS) to promote capsular polysaccharide (CPS)-specific phage infection by upregulating
ugd
expression, which is necessary for the synthesis of
Autographiviridae
phage receptor CPS. Although increased CPS-specific phage susceptibility is a novel trade-off mediated by QS, it results in the upregulation of virulence factors, promoting biofilm development and enhanced capsular polysaccharide production in
V. alginolyticus
. This suggests that inhibiting QS may improve the effectiveness of antibiotic treatment, but it may also reduce the efficacy of phage therapy.
Funder
National Natural Science Foundation of China
Jiangsu Agricultural Science and Technology Innovation Fund
Fundamental Research Funds for the Central Universities
Postgraduate Research Practice Innovation Program of Jiangsu Province
Publisher
American Society for Microbiology