Microbiological quality of natural waters on the resistance profile of heterotrophic bacteria to antimicrobials

Abstract

The hospital clinic daily faces therapeutic challenges arising from the presence of multidrug-resistant bacteria to antibiotics. However, considering there is evidence of multi-resistant bacteria in soil and water environments, this study aimed to evaluate the microbiological aspects of potential natural water sources for consumption in the city of Itajubá (MG, Brazil), including the determination of the resistance profile of heterotrophic bacteria to antimicrobials, which is not required in the current potability criteria. Thus, we performed analyzes of the microbiological characteristics in 11 channeled sources during the rainy season and nine sources during the dry season, including total coliforms, Escherichia coli, density of heterotrophic bacteria and resistance testing of heterotrophic bacteria to antimicrobial agents, besides physical and chemical characteristics. The results showed high resistance percentages of heterotrophic bacteria to antimicrobials, unrelated to the sampling time. However, there was no relationship between bacterial resistance and density of heterotrophic bacteria and total coliforms, which can lead to the false idea of the absence of risk in the natural studied waters presenting low contamination.