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

• Published in: Food science and biotechnology Vol. 29; no. 9; pp. 1273 - 1279
• Main Authors: Maerani, Maerani, Dewanti-Hariyadi, Ratih, Nurjanah, Siti
• Format: Journal Article
• Language: English
• Published: Singapore Springer Singapore 01-09-2020; Springer Nature B.V
• Subjects: Acids; Chemistry; Chemistry and Materials Science; Cronobacter sakazakii; Food Science; Gene expression; Genes; Nutrition; Pathogenicity; Pathogens; Stress; Virulence; Unculturable; Acid stress; Virulence genes; Stress regulator genes; Cronobacter sakazakii
• ISSN: 1226-7708; 2092-6456
• DOI: 10.1007/s10068-020-00763-1

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