Environmental health of water bodies from a Brazilian Amazon Metropolis based on a conventional and metagenomic approach.

This study investigated the microbiological diversity and contamination of water bodies in drainage channels and rivers in Belém, a major city in the Brazilian Amazon, using conventional and metagenomic methods. Results revealed the presence of 473 bacterial and 83 viral families, including human-associated pathogens and enteric viruses, with widespread fecal contamination indicated by high levels of bacterial and viral indicators exceeding local standards. The study identified 63 bacterial resistance genes conferring resistance to 13 antimicrobial classes and confirmed viral viability in the environment, highlighting multiple mechanisms of antimicrobial resistance. Physicochemical analyses showed elevated levels of biochemical oxygen demand, dissolved oxygen deficits, turbidity, and metals (cadmium, iron, manganese) above recommended limits, reflecting significant environmental degradation linked to inadequate waste disposal and poor sanitation infrastructure. The findings underscore urgent needs for improved environmental management and public health interventions to protect water quality and reduce risks of waterborne diseases in this Amazonian urban setting.