title: Induction of the Yersinia pestis PhoP-PhoQ regulatory system in the flea and its role in producing a transmissible infection.
abstract: Transmission of Yersinia pestis is greatly enhanced after it forms a bacterial biofilm in the foregut of the flea vector that interferes with normal blood feeding. Here we report that the ability to produce a normal foregut-blocking infection depends on induction of the Y. pestis PhoP-PhoQ two-component regulatory system in the flea. Y. pestis phoP-negative mutants achieved normal infection rates and bacterial loads in the flea midgut but produced a less cohesive biofilm both in vitro and in the flea and had a greatly reduced ability to localize to and block the flea foregut. Thus, not only is the PhoP-PhoQ system induced in the flea gut environment, but also this induction is required to produce a normal transmissible infection. The altered biofilm phenotype in the flea was not due to lack of PhoPQ-dependent or PmrAB-dependent addition of aminoarabinose to the Y. pestis lipid A, because an aminoarabinose-deficient mutant that is highly sensitive to cationic antimicrobial peptides had a normal phenotype in the flea digestive tract. In addition to enhancing transmissibility, induction of the PhoP-PhoQ system in the arthropod vector prior to transmission may preadapt Y. pestis to resist the initial encounter with the mammalian innate immune response.
authors: Laboratory of Zoonotic Pathogens, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA.
authors: Roberto
authors: R
authors: Rebeil
authors: Clayton O
authors: CO
authors: Jarrett
authors: James D
authors: JD
authors: Driver
authors: Robert K
authors: RK
authors: Ernst
authors: Petra C F
authors: PC
authors: Oyston
authors: B Joseph
authors: BJ
authors: Hinnebusch
mesh_terms: D000818:Animals; D001179:Arthropod Vectors / Q000382:microbiology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D008297:Male; D051379:Mice; D010930:Plague / Q000382:microbiology* / Q000469:parasitology / Q000635:transmission*; D005423:Siphonaptera / Q000382:microbiology*; D014774:Virulence; D015010:Yersinia pestis / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity
chemical_list: D001426:Bacterial Proteins; C079792:PhoQ protein, Bacteria; C061064:PhoP protein, Bacteria