Genetic regulation of airway colonization by Bordetella species.
Bordetella species are respiratory pathogens that infect humans and other animals. A majority of the virulence factors expressed by these bacteria are regulated by a master control locus, BvgAS, a member of the two-component family of signal transduction systems. BvgAS senses environmental signals and mediates signal transduction by a phosphorylation cascade that leads to a biphasic transition between the Bvg+ and Bvg- phases. From natural host studies using Bordetella bronchiseptica, we have found that expression of Bvg+ phase factors, which include adhesins and toxins, is required for successful colonization of the mammalian respiratory tract. Suppression of the Bvg- phase motility phenotype is necessary for a successful interaction with the host. Although the Bvg- phase does not appear to be required in vivo, it does confer the ability to survive under conditions of severe nutrient deprivation. We hypothesize that the Bvg+ phase is necessary and sufficient for respiratory tract colonization and the Bvg- phase is adapted for survival in environments encountered during transmission between hosts.
Yuk
M H
MH
Department of Microbiology and Immunology, School of Medicine, University of California, Los Angeles, USA.
Cotter
P A
PA
Miller
J F
JF
D000818:Animals; D001884:Bordetella / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity; D006801:Humans; D010641:Phenotype; D010766:Phosphorylation; D012137:Respiratory System / Q000382:microbiology*; D015398:Signal Transduction / Q000235:genetics; D014774:Virulence / Q000235:genetics