Multivariate statistical analysis of surface water quality in the capibaribe river (Pernambuco state, Northeast Brazil): Contributions to water management

Abstract

Assessing the quality of surface waters is essential for identifying changes in freshwater ecosystems and supporting the planning/proposing of measures to mitigate polluting sources. However, many studies involving the identification of pathogenic bacteria and/or their resistance profile to antimicrobial agents need a more holistic approach to conditioning or modulating factors. Thus, we apply different multivariate statistical techniques to the data set from the Capibaribe River's surface water, one of the most important in the Northeast of Brazil. Our data, taken together, suggest that the waters of the Capibaribe River have been suffering impacts associated with different human activities. Due to its flow crossing a large urban area, different sources are contributing to the contamination/pollution of its aquatic ecosystem, whose multivariate analysis allowed us to identify site-dependent characteristics that reflect the degree and type of human influence. The study of physical-chemical and chemical parameters reveals the influence of the high load of effluents (industrial and domestic) on the chemical and microbiological quality of the waters sampled at the SS4 site. On the other hand, the antimicrobial resistance profile of the isolates evaluated, especially at SS1, SS2, and SS3 sites, provides a comprehensive sample of the “resistome” present in the fecal content of thousands of people living in the region surrounding the Capibaribe River. The presence of enterobacteria in water indicates contamination of fecal origin. It represents a public health problem since the waters of the Capibaribe River can be a source of dissemination and persistence of bacteria resistant to humans and the environment. In conclusion, our study provides a more comprehensive understanding of the relationships between surface water, basic sanitation, antibiotic exposure, bacterial gene transfer, and human colonization, whether in the context of the region studied or other locations.