Pathogenic bacteria use specific host factors to modulate virulence and stress responses during infection. We found previously that the host factor bile and the bile component glyco-conjugated cholate (NaGCH, sodium glycocholate) upregulate the colonization factor CS5 in enterotoxigenic Escherichia coli (ETEC). To further understand the global regulatory effects of bile and NaGCH, we performed Illumina RNA-Seq and found that crude bile and NaGCH altered the expression of 61 genes in CS5 + CS6 ETEC isolates. The most striking finding was high induction of the CS5 operon (csfA-F), its putative transcription factor csvR, and the putative ETEC virulence factor cexE. iTRAQ-coupled LC-MS/MS proteomic analyses verified induction of the plasmid-borne virulence proteins CS5 and CexE and also showed that NaGCH affected the expression of bacterial membrane proteins. Furthermore, NaGCH induced bacteria to aggregate, increased their adherence to epithelial cells, and reduced their motility. Our results indicate that CS5 + CS6 ETEC use NaGCH present in the small intestine as a signal to initiate colonization of the epithelium.
1.Karolinska Inst, Dept Microbiol Tumor & Cell Biol, Box 280, S-17177 Stockholm, Sweden 2.Univ Gothenburg, Inst Biomed, Dept Microbiol & Immunol, Box 435, S-40530 Gothenburg, Sweden 3.Chinese Acad Sci, Inst Microbiol, CAS Key Lab Pathogen Microbiol & Immunol, Beijing, Peoples R China 4.Univ Arkansas Med Sci, Coll Med, Dept Biomed Informat, Little Rock, AR 72205 USA 5.Zhejiang Univ, Affiliated Hosp 1, Coll Med, Collaborat Innovat Ctr Diag & Treatment Infect Di, Hangzhou, Zhejiang, Peoples R China 6.Southwest Med Univ, Sch Basic Med Sci, Dept Pathogen Biol, Zhongshan Rd, Luzhou, Sichuan, Peoples R China
Recommended Citation:
Joffre, Enrique,Nicklasson, Matilda,Alvarez-Carretero, Sandra,et al. The bile salt glycocholate induces global changes in gene and protein expression and activates virulence in enterotoxigenic Escherichia coli[J]. SCIENTIFIC REPORTS,2019-01-01,9