Identificação e distinção de fonte de poluição fecal na Bacia Hidrográfica Ribeirão João Leite por metodologias moleculares

• Autor(a) principal: Buma, Eni Liudmiliza Leite
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/7039
• topic: Água bruta superficial; Poluição fecal; Bacteroidales; Marcador genético 16S rRNA; Surface raw water; Fecal pollution; Bacteroidales; 16S rRNA genetic marker; CIENCIAS BIOLOGICAS::MICROBIOLOGIA

Water courses that pass through areas of production, whether agricultural, pasture or housing, are subject to discharge of municipal and industrial sewage systems. These waters can be directed to river basins and redistributed to networks of water treatment and public supply. Normally, surface raw water has high concentrations of total coliforms, thermotolerant coliforms and E. coli. However, the microbiological indicator of fecal contamination, E. coli, does not present specificity, limiting, therefore, the host identification causing fecal pollution in water stream. As an alternative, bacteria of the genus Bacteroides have been suggested as potential alternative indicators of fecal pollution. Bacteroides are strictly anaerobic, exclusive and specific to the human gastrointestinal tract, and are also present in homeothermic animals. Because its inability to withstand aerobic environments, Bacteroides are considered as promising indicators of recent fecal pollution. Their identification in water bodies is usually performed by the presence of the 16S rRNA genetic marker of the order Bacteroidales. The objective of this study was to evaluate the microbiological and physico-chemical quality of the water of the Ribeirão João Leite Basin, responsible to supply 50% of water to the city of Goiânia, as well as the evaluation of the 16S rRNA Bacteroidales marker as an indicator of human and / or animal fecal pollution in waters of this basin. For this purpose, 91 samples of surface freshwater were collected from 13 points located along the Ribeirão João Leite Hydrographic Basin extension. Also, human and animal fecal samples were collected to test the sensitivity and specificity of primers to trace the 16S rRNA Bacteroidales marker. Based on the CONAMA Resolution 357/2005 Class II for fresh water, 5.5% (5/91) of the samples had a turbidity level above > 100 NTU (119-180 NTU), while 33% presented values below <103 CFU / 100 mL for thermotolerant E. coli. The mean values were found to be between 1.24 x 103-5.03 x 104 CFU / 100 mL. The 16S rRNA Bacteroidales ruminant host marker was identified in points with high agricultural and cattle influence, on the other hand, the presence of the 16S rRNA Bacteroidales marker as an indicator of human fecal pollution was not detected in the 5 analyzed points. The results obtained will be able to collaborate with sanitary measures to reduce the level of turbidity and also to identify the source of the fecal contamination in these bodies of water, thus minimizing the risk of dissemination of waterborne diseases.