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The role of Bacillus anthracis germinant receptors in germination and virulence
Author(s) -
Carr Katherine A.,
Lybarger Suzanne R.,
Anderson Erica C.,
Janes Brian K.,
Hanna Philip C.
Publication year - 2010
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.2009.06972.x
Subject(s) - virulence , receptor , biology , bacillus anthracis , mutant , microbiology and biotechnology , germination , spore germination , spore , biochemistry , gene , bacteria , genetics , botany
Summary Nutrient‐dependent germination of Bacillus anthracis spores is stimulated when receptors located in the inner membrane detect combinations of amino acid and purine nucleoside germinants. B. anthracis produces five distinct germinant receptors, GerH, GerK, GerL, GerS and GerX. Otherwise isogenic mutant strains expressing only one of these receptors were created and tested for germination and virulence. The GerH receptor was necessary and sufficient for wild‐type levels of germination with inosine‐containing germinants in the absence of other receptors. GerK and GerL were sufficient for germination in 50 mM L‐alanine. When mutants were inoculated intratracheally, any receptor, except for GerX, was sufficient to allow for a fully virulent infection. In contrast, when inoculated subcutaneously only the GerH receptor was able to facilitate a fully virulent infection. These results suggest that route of infection determines germinant receptor requirements. A mutant lacking all five germinant receptors was also attenuated and exhibited a severe germination defect in vitro . Together, these data give us a greater understanding of the earliest moments of germination, and provide a more detailed picture of the signals required to stimulate this process.