Open AccessCold shock protein A plays an important role in the stress adaptation and virulence of B rucella melitensis
Author(s) -
Wang Zhen,
Wang Shuangshan,
Wu Qingmin
Publication year - 2014
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/1574-6968.12430
Subject(s) - brucella melitensis , virulence , brucella , microbiology and biotechnology , biology , mutant , intracellular parasite , intracellular , gene , brucella suis , pathogen , bacteria , virology , genetics , brucellosis
B rucella melitensis is a facultative intracellular pathogen that mainly resides within macrophages. The mechanisms employed by B rucella to adapt to harsh intracellular environments and survive within host macrophages are not clearly understood. Here, we constructed a cspA gene deletion mutant, NI Δ cspA , that did not exhibit any discernible growth defect at a normal culture temperature (37 °C) or at a low temperature (15 °C). However, expression of the cspA gene in B rucella was induced by cold, acidic, and oxidative conditions, as determined via quantitative reverse transcription PCR . Unlike its parental strain, B . melitensis NI , the NI Δ cspA mutant showed an increased sensitivity to acidic and H 2 O 2 stresses, especially during the mid‐log‐phase, and these stress conditions would presumably be encountered by bacteria during intracellular infections. Moreover, macrophage and mouse infection assays indicated that the NI Δ cspA mutant fails to replicate in cultured J774.A1 murine macrophages and is rapidly cleared from the spleens of experimentally infected BALB /c mice. These findings suggest that the B rucella cspA gene makes an essential contribution to virulence in vitro and in vivo , most likely by allowing brucellae to adapt appropriately to the harsh environmental conditions encountered within host macrophages.