Genomic, transcriptomic analyses and phenotypic characterization of Campylobacter jejuni strains isolated from different sources in Brazil

• Grant number: 23/16616-2
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: April 01, 2024
• End date: July 31, 2027
• Field of knowledge: Agronomical Sciences - Veterinary Medicine
• Principal Investigator: Juliana Pfrimer Falcão
• Grantee: Giovana do Nascimento Pereira
• Host Institution: Faculdade de Ciências Farmacêuticas de Ribeirão Preto (FCFRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Campylobacteriosis is one of the main diarrheagenic diseases in different countries. The species Campylobacter jejuni is responsible for approximately 90% of these infections in humans, and poultry meat is the main vehicle for its transmission. In Brazil, there is a lack of C. jejuni studies and its isolation has been unfrequently, since in the country there is no surveillance program for reporting infection by this genus, making it difficult to assess its importance in our country. This project aims to comparatively analyze, through whole genome sequencing (WGS) data, transcriptome sequencing and by phenotypic tests related to virulence and survival, Campylobacter jejuni strains isolated from different sources over 27 years in Brazil. Genomic analyses will be performed for 140 C. jejuni strains isolated from humans (n=49), animals (n=50), and food (n=41) for the presence of pathogenicity and metabolic islands, presence of plasmids, core genome Multilocus Sequence Typing (cgMLST), Average Nucleotide Identity (ANI), pangenome analysis, spacer sequences of the CRISPR system analysis, prediction of Transducer like proteins (Tlps) genes and reverse vaccinology approach for the prediction of possible vaccine targets. For 60 selected strains, phenotypic tests of freezing and pasteurization tolerance, biofilm formation and peracetic acid survival will be performed. Furthermore, for 30 selected strains, a survival test in co-culture with Salmonella sp. and in vivo assay using chicken embryo chorioallantoic membrane will be performed. Finally, the transcriptome analysis of one C. jejuni strain subjected to the Simulator of the human intestinal microbial ecosystem (SHIME®) will be performed. The results to be obtained in the present work should contribute to a better phenotypic and molecular characterization of C. jejuni strains, providing unprecedented and extremely relevant information about the possible differences in pathogenicity, virulence, possible vaccine targets and genotypic diversity of strains isolated from humans, animals, and food during 27 years in Brazil.