OBJECTIVE:

To describe the occurrence of ARGs according to spatial and seasonal variability in the Tucuruí Hydroelectric Plant reservoir.

MATERIALS AND METHODS:

Samples were collected from the photic, aphotic, and sediment layers at the Montante 1 and Montante Novo Repartimento stations during the Amazonian summer and winter. DNA was extracted and sequenced on the Ion Proton platform for metagenomic analysis. De novo assembly was performed using MEGAHIT, open reading frames were predicted with Prodigal, and ARGs were identified using the CARD and MEGARes databases. Contigs containing ARGs were generated for subsequent analyses. Statistical analyses were conducted in R using the ggplot2 package.

RESULTS:

The most abundant ARGs in the samples were those related to beta-lactams (3,317.92 ×/Gb), macrolide-lincosamide-streptogramin (1,079.77 ×/Gb), tetracyclines (968.23 ×/Gb), aminoglycosides (779.25 ×/Gb), and multidrug resistance genes (698.94 ×/Gb). These ARGs occurred predominantly during the Amazonian winter in the surface layer of the reservoir.

CONCLUSION:

The outcomes screen significant anthropogenic influence and concern regarding the spread of antibiotic resistance genes in the Tucuruí Hydroelectric Plant reservoir.