Coordinated Bacteriocin Expression and Competence in Streptococcus pneumoniae Contributes to Genetic Adaptation through Neighbor Predation

• Published in: PLoS pathogens Vol. 12; no. 2; p. e1005413
• Main Authors: Wholey, Wei-Yun, Kochan, Travis J, Storck, David N, Dawid, Suzanne
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 03.02.2016; Public Library of Science (PLoS)
• Subjects: Acquisitions & mergers; Adaptation; Adaptation, Biological - genetics; Antibiotics; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Bacteriocins; Bacteriocins - genetics; Bacteriocins - metabolism; Bacteriology; Binding sites; Biofilms; Biology and Life Sciences; Competition; Deoxyribonucleic acid; DNA; DNA, Bacterial - genetics; Drug resistance; Funding; Gene expression; Gene Expression Regulation, Bacterial; Genetic aspects; Genetic engineering; Health aspects; Humans; Medicine and Health Sciences; Nucleotide Motifs; Operon - genetics; Peptides; Pheromones - genetics; Pheromones - metabolism; Predation; Promoter Regions, Genetic - genetics; Proteins; Quorum Sensing; Streptococcus infections; Streptococcus pneumoniae; Streptococcus pneumoniae - chemistry; Streptococcus pneumoniae - genetics; Streptococcus pneumoniae - physiology
• ISSN: 1553-7374; 1553-7366; 1553-7374
• DOI: 10.1371/journal.ppat.1005413

Streptococcus pneumoniae (pneumococcus) has remained a persistent cause of invasive and mucosal disease in humans despite the widespread use of antibiotics and vaccines. The resilience of this organism is due to its capacity for adaptation through the uptake and incorporation of new genetic material from the surrounding microbial community. DNA uptake and recombination is controlled by a tightly regulated quorum sensing system that is triggered by the extracellular accumulation of competence stimulating peptide (CSP). In this study, we demonstrate that CSP can stimulate the production of a diverse array of blp bacteriocins. This cross stimulation occurs through increased production and secretion of the bacteriocin pheromone, BlpC, and requires a functional competence regulatory system. We show that a highly conserved motif in the promoter of the operon encoding BlpC and its transporter mediates the upregulation by CSP. The accumulation of BlpC following CSP stimulation results in augmented activation of the entire blp locus. Using biofilm-grown organisms as a model for competition and genetic exchange on the mucosal surface, we demonstrate that DNA exchange is enhanced by bacteriocin secretion suggesting that co-stimulation of bacteriocins with competence provides an adaptive advantage. The blp and com regulatory pathways are believed to have diverged and specialized in a remote ancestor of pneumococcus. Despite this, the two systems have maintained a regulatory connection that promotes competition and adaptation by targeting for lysis a wide array of potential competitors while simultaneously providing the means for incorporation of their DNA.