Small non-coding RNA STnc640 regulates expression of fimA fimbrial gene and virulence of Salmonella enterica serovar Enteritidis

Xia Meng,Xianchen Meng,Guoqiang Zhu,Jie Ni,Heng Wang,Jinqiu Wang,Chunhong Zhu

doi:10.1186/s12917-019-2066-7

Xia Meng, Xianchen Meng + Show 5 more

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https://doi.org/10.1186/s12917-019-2066-7

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Abstract

BackgroundSmall non-coding RNAs (sRNAs) regulate bacterial gene expression at the post-transcriptional level. STnc640 is a type of sRNA that was identified in Salmonella Typhimurium.ResultsIn this study, STnc640 in Salmonella Enteritidis was confirmed to be an Hfq-dependent sRNA. TargetRNA software analysis showed that fimbrial genes fimA and bcfA were likely to be the target genes of STnc640. To investigate the target mRNAs and function of STnc640 in pathogenicity, we constructed the deletion mutant strain 50336△stnc640 and the complemented strain 50336△stnc640/pstnc640 in Salmonella Enteritidis 50336. The RT-qPCR results showed that the mRNA level of fimA was decreased, while bcfA was unchanged in 50336△stnc640 compared with that in the wild type (WT) strain. The adhesion ability of 50336△stnc640 to Caco-2 cells was increased compared to the 50336 WT strain. The virulence of 50336△stnc640 was enhanced in a one-day-old chicken model of S. Enteritidis disease as determined by quantifying the 50% lethal dose (LD50) of the bacterial strains.ConclusionsThe results demonstrate that STnc640 contributes to the virulence of Salmonella Enteritidis.

Highlights

Small non-coding RNAs regulate bacterial gene expression at the post-transcriptional level
STnc640 is a novel Hfq-binding Small non-coding RNAs (sRNAs) that was identified in Salmonella Typhimurium through deep sequencing and transcriptomic analysis of Hfq-bound sRNAs and mRNAs [19]
Hfq plays a positive role on STnc640 stability To determine whether the stability of STnc640 depends on the sRNA chaperone protein Hfq, the abundance of stnc640 transcripts in S

Summary

Introduction

Small non-coding RNAs (sRNAs) regulate bacterial gene expression at the post-transcriptional level. STnc640 is a type of sRNA that was identified in Salmonella Typhimurium. SRNAs regulate many physiological processes, including metabolism, iron homeostasis, outer membrane protein biosynthesis, quorum sensing, and virulence [5,6,7,8]. Many of these sRNAs require the RNA-chaperone Hfq [9]. Salmonella enterica serovar Enteritidis is an important Gram-negative intracellular pathogen with a broad host range. STnc640 is a novel Hfq-binding sRNA that was identified in Salmonella Typhimurium through deep sequencing and transcriptomic analysis of Hfq-bound sRNAs and mRNAs [19].

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