Dissecting the virulence of an enteropathogenic/enteroaggregative Escherichia coli (EPEC/EAEC) Hybrid isolate

• Grant number: 24/13700-5
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: May 01, 2025
• End date: February 29, 2028
• Field of knowledge: Biological Sciences - Microbiology - Biology and Physiology of Microorganisms
• Principal Investigator: Rodrigo Tavanelli Hernandes
• Grantee: Iranildo do Amarante Fernandes
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Associated research grant: 17/14821-7 - Exploring novel virulence strategies in Escherichia coli, AP.TEM

Abstract

Collectively, Escherichia coli isolates associated with gastrointestinal tract infections are known as diarrheagenic E. coli (DEC), and based on their virulence factors, DEC can be subgrouped into six distinct pathotypes. From an epidemiological point of view, enteropathogenic E. coli (EPEC) and enteroaggregative E. coli (EAEC) are the most frequently DEC pathotypes isolated from stool samples of individuals with diarrhea in Brazil. The hallmark of EPEC virulence is the ability to induce a lesion in host cells termed attaching and effacing (AE), which leads to the destruction of the intestinal microvilli. On the other hand, the phenotypic hallmark of EAEC is adherence to epithelial cells in an aggregative pattern (AA), mediated by the aggregative adherence fimbriae (AAF/I - AAF/V), and characterized by the organization of the bacteria cells resembling stacked bricks. The high plasticity of the E. coli genome can lead to the emergence of isolates with more than one DEC markers in its genome, and these isolates are currently known as hybrids. Recently, our laboratory described the isolation of an EPEC/EAEC hybrid of serotype O3:H2 during a Brazilian diarrheal outbreak investigation. The study of the genome of these hybrids confirmed the concomitantly presence of EPEC and EAEC markers located on the chromosome and on a high molecular weight plasmid, respectively. However, to date, the impact of this gene combination on the pathogenicity of EPEC/EAEC hybrid isolates is an answered question. Facing the scenario, the main of the present study is to determine the molecular and phenotypic characteristics of an EPEC/EAEC hybrid isolate; and to establish whether this combination of virulence factors could potentiate the pathogenicity of this hybrid.