Expression of stress regulator and virulence genes of Cronobacter sakazakii strain Yrt2a as a response to acid stress

다국어 초록 (Multilingual Abstract)

This research aimed to evaluate the effect of acidstress on the expression of stress regulator (grxB and rpoS)and virulence (ompA, hfq, and cpa) genes of Cronobactersakazakii Yrt2a. The results showed that C. sakazakii Yrt2aexperienced decrease in number during acid stress and wasno longer culturable 90 min post exposure to pH 3.0.
During acid stress, the expression of grxB, rpoS, ompA, cpaand hfq was upregulated by 2.15; 2.19; 1.55; 1.1 and 1.41log, respectively. However, all genes expression wasdownregulated when the bacteria entered the unculturablestate. The expression of gene grxB, rpoS, ompA, cpadecreased to 1.04; 0.37; 0.84 and 1.71 log, respectively;while hfq gene expression reached a level lower than thatof control. This research implies a supposition that duringacid stress, C. sakazakii was capable of maintaining itsculturability and pathogenicity until they are no longerculturable.