Albumin Inhibits Pseudomonas aeruginosa Quorum Sensing and Alters Polymicrobial Interactions.

Polymicrobial interactions are complex and can influence the course of an infection, as is the case when two or more species exhibit a synergism that produces a disease state not seen with any of the individual species alone. Cell-to-cell signaling is key to many of these interactions, but little is understood about how the host environment influences polymicrobial interactions or signaling between bacteria. Chronic wounds are typically polymicrobial, with and being the two most commonly isolated species. While readily kills , the two species can coexist for long periods together in chronic wound infections. In this study, we investigated the ability of components of the wound environment to modulate interactions between and We demonstrate that quorum sensing is inhibited by physiological levels of serum albumin, which appears to bind and sequester some homoserine lactone quorum signals, resulting in the inability of to produce virulence factors that kill These data could provide important clues regarding the virulence of in albumin-depleted versus albumin-rich infection sites and an understanding of the nature of friendly versus antagonistic interactions between and .