Gene resistance profile and multidrug-resistant bacteria isolated from a stream in midwestern Brazil

Abstract

Freshwater environments are susceptible to contamination by antibiotics, antibiotic resistant bacteria (ABRs) and antibiotic resistance genes (ARGs). Contaminants come from diffuse and point sources, such as surface runoff, sewage and leaching. The increase in the prevalence of ARBs and ARGs is of global importance, having a direct impact on public health, due to the increase in resistant pathogenic strains and the lack of effective antibiotic therapy. In this context, the general objective of this study was to verify the prevalence of ARBs and ARGs in water and sediment samples, evaluating the microbiological quality of the João Leite stream. Bacterial cultures (bacterial counting, multi-tube analysis, bacterial isolation, identification by bacterial phenotype and antibiogram) and qPCR test to identify ARGs were performed. The microbiological quality of the water is not in accordance with Brazil current legislation, being unsuitable even for primary contact recreation (bath and leisure), having a large amount of coliforms and E. coli. The most isolated phylum was Proteobacteria and Firmicutes. ABRs were 62.64% resistant to CFZ (Cefazolin), 54.97% resistant to AMP (ampicillin), 47.56% resistant to CLI (clindamycin) and 45.05% resistant to AMC (amoxicillin/clavulanic acid). Multidrug resistance was found in 31.79% of the isolates. Were detected ABRs in all water and sediment samples in this study, with the presence of some antibiotic resistance gene. ARGs were more found in water samples, with genes encoding resistance to β-lactams, macrolides, quinolones, fluoroquinolone, tetracyclines and sulfonamides being detected. Statistically significant correlations between ARBs and ARGs were detected, it is suggested that anthropogenic activities are related to the presence of these emerging contaminants (ARBs and ARGs) in the João Leite stream, requiring constant monitoring and research in this area.