Caracterización Microbiológica de muestras de aguas servidas pre filtradas de la comunidad de San Vicente de Lacas de la Provincia de Chimborazo

Abstract

The main objective of this research study was to characterize samples of pre-filtered residual water from the Community of San Vicente de Lacas in the province of Chimborazo. The investigation started with sampling, purification, and characterization of bacteria. For which there was an experimental approach, standards were applied for the analysis of microbiological studies of the water, while for the discussion and comparison of the evidence found in documents such as the “Guía de Calidad Ambiental para Aguas del Ecuador” and the unified text of secondary environmental legislation (TULSMA) were taken into account. For microbiological analysis, samples were taken from the final effluent of the treatment plant of the Community of San Vicente de Lacas, the period March-May 2021. The bacterial identification was based on the type of bacteria of clinical importance as they were; Escherichia coli, Escherichia coli inactive, Edwarsiella tarda, Shigella flexneri, Klebsiella pneumoniae, Salmonella paratyphi, Pseudomona oryzihabitans, and Staphylococcus aureus, for which depletion seeding techniques were used and biochemical tests. On the other hand, to confirm the presence of total coliforms, fecal coliforms, and Escherichia coli, the multi-tube fermentation technique results exceeded maximum standards, and the allowable limits established by TULSMA. In addition, antibiograms were analyzed showing sensitivity resistance and a high degree of multi-resistance from the bacteria; Staphylococcus aureus, Shigella flexneri, Salmonella paratyphi y Edwardsiella tarda. It was concluded that these results mainly show that the primary treatment process of prefiltration of the residual water is not enough to provide a suitable resource in order to reuse the water in agriculture, much less for animal or human consumption. Therefore, it is recommended to carry out another study with samples of the pre- filtered residual water taken at night time and during the summer.