Phage resistance at the cost of virulence

October 07, 2019


Phage resistance at the cost of virulence: Listeria monocytogenes serovar 4b requires galactosylated teichoic acids for InlBmediated invasion
PLOS Pathogens | October 7, 2019


L. monocytogenes is a Gram-positive, food-borne, intracellular pathogen that causes severe infection in susceptible individuals. Interestingly, almost all infections are caused by a subset of strains belonging to certain serovars featuring a complex glycosylation pattern on their cell surface. Using an engineered bacteriophage that specifically recognizes these modifications we selected for mutants that lost these sugars. We found that the resulting strains are severely deficient in invading host cells as we observed that a major virulence factor mediating host cell entry requires galactose decoration of the cell surface for its function. Without this galactose decoration, the strain represents a serovar not associated with disease. Altogether, we show a complex interplay between bacteriophages, bacteria, and the host, demonstrating that cellular invasiveness is dependent upon a serovar-defining structure, which also serves as a phage receptor.


Eric T. Sumrall, Yang Shen, Anja P. Keller, Jeanine Rismondo, Maria Pavlou, Marcel R. Eugster, Samy Boulos, Olivier Disson, Pierre Thouvenot, Samuel Kilcher, Bernd Wollscheid, Didier Cabanes, Marc Lecuit, Angelika Gründling, Martin J. Loessner