Impact of the presence of pAA plasmids on the virulence phenotypes of hybrid strains of uropathogenic Escherichia coli.

• Grant number: 23/14882-7
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Effective date (Start): March 01, 2024
• Effective date (End): March 31, 2028
• Field of knowledge: Biological Sciences - Microbiology - Biology and Physiology of Microorganisms
• Principal Investigator: Tânia Aparecida Tardelli Gomes do Amaral
• Grantee: Natalia Victoriano de Araujo
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil

Abstract

Pathogenic strains of Escherichia coli were considered to have the ability to cause only intestinal (II) or extraintestinal (IEI) infections. However, recent studies have reported the occurrence of strains of E. coli leading to both types of infections in the same patient. The frequent isolation of enteroaggregative E. coli (EAEC) from sites of extraintestinal infections has raised the question about the relevance of pAA plasmids, encoding the main virulence factors of this pathotype, in the pathogenesis of extra-intestinal infections. Aiming to understand whether the presence of pAA plasmids could contribute to increasing the virulence potential of ExPEC strains, the contribution of the pAA plasmid to the extra intestinal virulence potential will be analyzed. Regarding the extraintestinal pathogenic potential, uropathogenic E. coli (UPEC) strains, which contained pAA, and isogenic strains, which had the pAA eliminated in vitro or transferred to commensal E. coli strains or those originating from infection of the urinary tract, which received pAA horizontally. The strains will be evaluated in vitro in resistance assays to the bactericidal activity of serum, interaction efficiency with different extraintestinal cell lines and growth efficiency. These strains will also be assessed in vivo to evaluate extraintestinal virulence and epigenetic changes, in an alternative model of Galleria mellonella.