Investigação de vibrio cholerae nas estações de tratamento de esgoto (ETEs) de Uberlândia-MG

Abstract

Cholera is a disease caused by Vibrio cholerae, a gram-negative enterotoxigenic bacterium of great epidemiological importance due to its epidemic capacity and lethal potential if not treated as an emergency. In addition, the pathogen is associated with poor socioeconomic conditions and urban disasters, such as floods, which may compromise the supply of drinking water and basic sanitation. These characteristics imply the need for constant monitoring of areas with endemic potential for the occurrence of the disease and free from the pathogen. Hence, this study aimed to monitor and identify different profiles of Vibrio cholerae in ETEs in Uberlândia-MG. During four months, collections were carried out at four strategic points determined by the Municipality of Uberlândia, and the microbiological and molecular analysis for identification of the bacterium Vibrio cholerae and determination of the presence of virulence genes afterward. Molecular analysis confirmed the Vibrio cholerae in 54.5% of the isolates (36/66), due to the presence of the ompW gene, with a significant increase (p<0.05) in prevalence in the last two months of evaluation. The tox, hlyA genes were identified in 100% (36/36) of the strains. The rtx and ompU genes in 97.2% (35/36) and 25.0% (9/36), respectively. The presence of the gene responsible for the synthesis of cholera toxin (ctxAB) was identified in 43.7% (7/16) of the isolates. There was a significant difference in the presence of the ompU gene in relation to the four ETEs, identified only in the Uberabinha ETE (9/10 – 90.0%) (p=0.0004). Of the four virulence profiles were discriminated, the most prevalent being that associated with the presence of ompW, tox, hly, and rtx genes, considered relevant in the occurrence of diarrhea and bacteremia cases. The confirmation of the species, including the genetic diversity point to the urgency of including differential diagnoses and complementary exams in cases of acute diarrhea, as well as epidemiological studies for traceability of its origin and the need to implement more effective control measures in the ETEs.