AUTHOR=Gao Xiaojian , Qian Qieqi , Zhu Yujie , Chen Zhen , Xu Jingwen , Xu Wenjing , Jiang Qun , Wang Jun , Zhang Xiaojun 

TITLE=Transcriptomic and phenotype analysis revealed the role of rpoS in stress resistance and virulence of pathogenic Enterobacter cloacae from Macrobrachium rosenbergii

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.1030955

DOI=10.3389/fmicb.2022.1030955

ISSN=1664-302X

ABSTRACT=<p><italic>Enterobacter cloacae</italic> is widely distributed in the aquatic environment, and has been determined as a novel pathogen of various aquatic animals recently. Our previous studies have indicated <italic>E. cloacae</italic> caused repeated infections in <italic>Macrobrachium rosenbergii</italic>, suggesting a high survival ability of the bacteria, and <italic>rpoS</italic> gene has been known to regulate stress response and virulence of many bacteria. In this study, the <italic>E. cloacae</italic>-<italic>rpoS</italic> RNAi strain was constructed by RNAi technology, and the regulation role of <italic>rpoS</italic> in stress resistance and virulence of <italic>E. cloacae</italic> was explored by transcriptomic and phenotype analysis. The transcriptome analysis showed a total of 488 differentially expressed genes (DEGs) were identified between <italic>rpoS</italic>-RNAi and wild-type strains, including 30 up-regulated genes and 458 down-regulated genes, and these down-regulated DEGs were mainly related to environmental response, biofilm formation, bacterial type II secretory system, flagellin, fimbrillin, and chemotactic protein which associated with bacterial survival and virulence. The phenotype changes also showed the <italic>E. cloacae</italic>-<italic>rpoS</italic> RNAi strain exhibited significantly decreasing abilities of survival in environmental stresses (starvation, salinity, low pH, and oxidative stress), biofilm production, movement, adhesion to cells, pathogenicity, and colonization to <italic>M. rosenbergii.</italic> These results reveal that <italic>rpoS</italic> plays an important regulatory role in environmental stress adaptation and virulence of <italic>E. cloacae.</italic></p>