Quorum sensing N-acyl homoserine lactones-SdiA enhances the biofilm formation of E. coli by regulating sRNA CsrB expression

Shebin Zhang; Yurong Shu; Weizheng Zhang; Zhenjie Xu; Youqiang Li; Song Li; Qiwei Li; Rui Xiong; Yifei Long; Jianping Liu; Yunyan Zhang; Cha Chen; Yang Lu

doi:10.1016/j.heliyon.2023.e21658

Quorum sensing N-acyl homoserine lactones-SdiA enhances the biofilm formation of E. coli by regulating sRNA CsrB expression

Heliyon. 2023 Oct 29;9(11):e21658. doi: 10.1016/j.heliyon.2023.e21658. eCollection 2023 Nov.

Authors

Shebin Zhang^{1

2}, Yurong Shu², Weizheng Zhang³, Zhenjie Xu^{1

2}, Youqiang Li⁴, Song Li¹, Qiwei Li¹, Rui Xiong¹, Yifei Long¹, Jianping Liu¹, Yunyan Zhang⁵, Cha Chen¹, Yang Lu^{6

1}

Affiliations

¹ Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, PR China.
² The Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, PR China.
³ Department of Laboratory Medicine, Guangzhou No.11 People's Hospital, Guangzhou Cadre Health Management Center, Guangzhou, PR China.
⁴ Department of Laboratory Medicine, The Affiliated Hexian Memorial Hospital of Southern Medical University, Guangzhou, PR China.
⁵ Affiliated Stomatology Hospital of Guangzhou Medical University, Guangzhou, PR China.
⁶ Department of Laboratory Medicine, The Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan People's Hospital Guangzhou, Qingyuan, PR China.

Abstract

As an important virulence phenotype of Escherichia coli, the regulation mechanism of biofilm by non-coding RNA and quorum sensing system has not been clarified. Here, by transcriptome sequencing and RT-PCR analysis, we found CsrB, a non-coding RNA of the carbon storage regulation system, was positively regulated by the LuxR protein SdiA. Furthermore, β-galactosidase reporter assays showed that SdiA enhanced promoter transcriptional activity of csrB. The consistent dynamic expression levels of SdiA and CsrB during Escherichia coli growth were also detected. Moreover, curli assays and biofilm assays showed sdiA deficiency in Escherichia coli SM10λπ or BW25113 led to a decreased formation of biofilm, and was significantly restored by over-expression of CsrB. Interestingly, the regulations of SdiA on CsrB in biofilm formation were enhanced by quorum sensing signal molecules AHLs. In conclusion, SdiA plays a crucial role in Escherichia coli biofilm formation by regulating the expression of non-coding RNA CsrB. Our study provides new insights into SdiA-non-coding RNA regulatory network involved in Escherichia coli biofilm formation.

Keywords: Biofilm formation; CsrB; Escherichia coli; N-acylhomoserinelactones; SdiA.