Avaliação da infecção por Escherichia coli enteroagregativa cepa 042 em modelo de desnutrição in vitro de células epiteliais intestinais (IEC-6)

Abstract

Enteroaggregative Escherichia coli (EAEC) is the most emerging and genetically heterogeneous pathotype, being considered an important enteric pathogen of childhood worldwide. In the semi-arid region of Brazil, it was found in 2019 that, in a total of 1,200 children with diarrhea, positivity for EAEC was more prevalent when compared to other enteric bacteria, being present in more than half of the cases and in half of the controls. The aim of this study was to develop an in vitro model of malnutrition to investigate the pathobiology of EAEC strain 042 in intestinal epithelial cells (IEC-6). IEC-6 cells were exposed to 50% nutrient reduction for seven days and infected with EAEC for three hours after starvation. Analyzes of cell proliferation, viability and morphology were carried out, in addition to the expression of proteins such as CDC2-p34, CDC 42, caspases 3, 8 and 9, CFTR, PEPT1 and SGLT1, and genes such as the FABP, ATF2, CREB1, ELK1 and FOXO3 a in the absence and presence of infection. The model developed demonstrated that the reduction of nutrients, in the presence and absence of infection, was capable of significantly reducing cell proliferation and viability, in addition to having negative impacts on cell diameter and area. In the face of infection, we observed that there was no significant difference in the number of bacterial colony-forming units, demonstrating that the nutritional status of the cell may not interfere with the propensity to infection. Malnutrition, with or without infection, did not significantly alter the protein expression of several markers. The lack of models of EAEC infection is a challenge in understanding its pathogenesis, especially due to the scarcity of models covering malnutrition and infection. More research exploring different bacterial concentrations and shorter analysis periods is needed.