Transcriptional regulation of the waaAE-coaD operon by PhoP and RcsAB in Yersinia pestis biovar Microtus

Dear Editor, Yersinia pestis, the causative agent of plague, is transmitted among mammals （including humans） primarily via the bite of infected fleas. Flea-borne transmission distinguishes Y. pestis from its progenitor Y. pseudotuberculosis, which is a mild food-borne pathogen （Zhou and Yang, 2011）. In Y. pestis, transmission by fleas involves the synthesis of biofilms that physically block the flea＇s proventriculus; Y. pseudotuberculosis does not produce biofilms in fleas （Zhou and Yang, 2011）. Thus, biofllm formation may play a key role in virulence differences between the species.