Occurrence and persistence of antibiotic resistance genes in wastewater treatment plants in Aracaju/SE/Brazil

Antibiotic resistance is one of the greatest threats to public health in the 21st century and the presence of antibiotic resistant determinants in wastewater may reflect the current local clinical resistance situation. The objective of this study was to detect the presence of antibiotic resistant genes (ARGs) in Wastewater Treatment Plants (WWTPs) localized in Aracaju/SE/Brazil and verify the role of WWTPs in limiting the spread of these contaminants in the environment. Samples of raw and treated sewage were collected from four WWTPs, and subjected to DNA extraction, PCR amplification and sequencing to detect ARGs for the most consumed antibiotics by the local population. The ARGs blaTEM, gyrA, sul1, aacC2, qnrS, ermB and tetM were detected in 100% of the raw sewage samples, while in the treated samples their prevalence was 100% for blaTEM, gyrA and sul1, 75% for aacC2 and 50% for qnrS, ermB and tetM. This study concluded that the consumption of antibiotics is intrinsic to the prevalence of ARGs in WWTPs. Considering that the treated effluent is released into nature and that the WWTPs were not designed to remove these emerging contaminants, the need for permanent monitoring and investments in efficient removal technologies is needed. Effluent analysis is an important surveillance tool for determining strategies to contain the environmental spread of antibiotic resistance.