Currently, Brazil is the largest exporter of chicken meat and the third largest producer in the world, therefore the poultry industry is important to domestic and export economies. Despite being an important economic sector, the poultry industry is subject to factors that could significantly affect its revenues and costs. Among them, the infections caused by avian pathogenic Escherichia coli (APEC) are responsible for high morbidity and mortality. Avian pathogenic strains are associated with extraintestinal infections and diseases are known as colibacillosis, which encompass the large number of different infections. Furthermore, studies have shown that APEC strains and Extra-intestinal pathogenic E. coli of human origin (ExPEC) share pathogenicity characteristics such as serogroups, phylogenetic groups, virulence related plasmids sequences, bacterial adhesion, iron uptake systems and toxins. Numerous studies have been conducted seeking to establish the mechanisms of pathogenicity, the identification of new markers and description of virulence proteins in APEC. However, more studies are needed to understand and identify the pathogenicity mechanisms and virulence factors related to this pathotype. The availability of genome sequences allows comparative analyses between different strains, enabling the access to gene content variability, genomic organization and comparative genomes studies. The comparison of Brazilian sequenced strains (SEPT362, SCI-07, O08 and S17) has allowed us to observe the great variability related to the presence/absence of virulence factors. Another important issue related to the study of the genomes was that approximately 20% of the annotated genes have unknown function and the gene product described as hypothetical protein. These results show the necessity to find new genes associated with virulence. Motivated by the need, our research group has already identified and characterized in silico, a gene encoding autotransporter protein, with adhesin domains, not described in APEC. The objective of this project is to build a mutated APEC strain, through the deletion of this autotransporter protein and verify its contribution to pathogenicity, their biological effects (adhesion and invasion abilities in cell lines grown in vitro, biofilm production, motility, etc.) and its influence on global gene transcription.
News published in Agência FAPESP Newsletter about the scholarship: