Plague bacteria biofilm blocks food intake

Abstract

Bubonic plague is transmitted to mammals, including humans, by the bites of fleas whose digestive tracts are blocked by a mass of the bacterium Yersinia pestis¹. In these fleas, the plague-causing bacteria are surrounded by an extracellular matrix of unknown composition², and the blockage depends on a group of bacterial genes known as the hmsHFRS operon³. Here we show that Y. pestis creates an hmsHFRS-dependent extracellular biofilm to inhibit feeding by the nematode Caenorhabditis elegans. Our results suggest that feeding obstruction in fleas is a biofilm-mediated process and that biofilms may be a bacterial defence against predation by invertebrates.