Fimbria-Encoding Gene yadC Has a Pleiotropic Effect on Several Biological Characteristics and Plays a Role in Avian Pathogenic Escherichia coli Pathogenicity

Author(s)

Verma, Renu ^[1] ; Galvao Rojas, Thas Cabrera ^[1] ; Maluta, Renato Pariz ^[1] ; Leite, Janana Luisa ^[1] ; Mendes da Silva, Livia Pilatti ^[1] ; Nakazato, Gerson ^[2] ; da Silveira, Wanderley Dias ^[1]

Affiliation

^[1] Univ Campinas UNICAMP, Inst Biol, Dept Genet Evolut & Bioagents, Campinas, SP - Brazil

^[2] Univ Londrina UEL, Ctr Biol Sci, Dept Microbiol, Londrina, PR - Brazil

• Document type: Journal article
• Source: Infection and Immunity; v. 84, n. 1, p. 187-193, JAN 2016.
• Web of Science Citations: 3

Abstract

The extraintestinal pathogen termed avian pathogenic Escherichia coli (APEC) is known to cause colibacillosis in chickens. The molecular basis of APEC pathogenesis is not fully elucidated yet. In this work, we deleted a component of the Yad gene cluster (yadC) in order to understand the role of Yad in the pathogenicity of the APEC strain SCI-07. In vitro, the transcription level of yadC was upregulated at 41 degrees C and downregulated at 22 degrees C. The yadC expression in vivo was more pronounced in lungs than in spleen, suggesting a role in the early steps of the infection. Chicks infected with the wild-type and mutant strains presented, respectively, 80% and 50% mortality rates. The Delta yadC strain presented a slightly decreased ability to adhere to HeLa cells with or without the D-mannose analog compared with the wild type. Real-time PCR (RT-PCR) assays showed that fimH was downregulated (P< 0.05) and csgA and ecpA were slightly upregulated in the mutant strain, showing that yadC modulates expression of other fimbriae. Bacterial internalization studies showed that the Delta yadC strain had a lower number of intracellular bacteria recovered from Hep-2 cells and HD11 cells than the wild-type strain (P< 0.05). Motility assays in soft agar demonstrated that the Delta yadC strain was less motile than the wild type (P< 0.01). Curiously, flagellum-associated genes were not dramatically downregulated in the Delta yadC strain. Taken together, the results show that the fimbrial adhesin Yad contributes to the pathogenicity and modulates different biological characteristics of the APEC strain SCI-07. (AU)

• FAPESP's process: 12/23289-3 - Deletion of putative invasin and DnaK genes from avian pathogenic Escherichia coli (APEC) strain SCI07 to study their role in pathogenicity and obtain attenuated vaccine strains
• Grantee: Renu Verma
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 12/04391-1 - Mutation in AI-2 Quorum Sensing system and analyses of gene expression in an Avian Pathogenic Escherichia coli (APEC) strain
• Grantee: Livia Pilatti Mendes da Silva
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 12/05073-3 - MOLECULAR CHARACTERIZATION OF AVIAN PATHOGENIC (APEC) AND HUMAN UROPATHOGENIC (UPEC) ESCHERICHIA COLI LINEAGES
• Grantee: Renato Pariz Maluta
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 13/09167-5 - Site-directed mutagenesis of a new autotransporter in an avian pathogenic Escherichia coli strain (APEC) and evaluation of the contribution of this gene to pathogenesis
• Grantee: Thaís Cabrera Galvão Rojas
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 14/04860-7 - Study and molecular characterization of Uropathogenics Escherichia coli strains and its potential as pathogenic strains for poultry (APEC)
• Grantee: Janaína Luisa Leite Garbim
• Support Opportunities: Scholarships in Brazil - Post-Doctoral