Molecular identification of diarrheagenic Escherichia coli in the watershed of Xopotó River, in Alto do Rio Doce, Brazil

ABSTRACT

The main purpose of this scientific research was to identify pathotypes of diarrheogenic Escherichia coli in the watershed of Xopotó River, in Alto do Rio Doce, Minas Gerais region, Brazil. The studies referring to the stirps diarrheagenics of E. coli in the environment in Brazil are scarce. The watershed chosen for the study suffers intense environmental degradation due the release of raw sewage into their water bodies and human activities, such as agriculture. The water collecting at 13 sampling points were held in two periods of the year 2015 (April and July). For the identification of the genes of diarrheagenic E. coli, the method of reaction polymerase chain (PCR) was used. The watershed presented pathogenic contamination of pathotypes Shiga toxin-producing E. coli (STEC), enteropathogenic E. coli (EPEC), and enterotoxigenic E. coli (ETEC) such a constant occurrence in both campaigns. The virulence genes observed were: STEC, Shiga toxin (Stx1), responsible for causing severe kidney disease as hemolytic-uremic syndrome (HUS). Besides that, EPEC presented only the virulent gene eae, characteristic of the atypical subgroup (aEPEC), as well as thermolabile toxins (LT). The presence of these pathotypes represents potential risk of diarrheagenic diseases in the population that uses the water resources, particularly the elderly and children, and demonstrates the commitment of the microbiological quality of constituents watercourses of the watershed of Xopotó River, mainly because the lack of sewage treatment facilities.

Keywords:
watershed of Xopotó River; Doce River; diarrheagenic Escherichia coli; polymerase chain reaction