Prevalence and diversity of multidrug-resistant Gram-negative bacteria in public aquatic environment and drinking water sources in São Paulo State: clinical and environmental impact

Abstract

The wide use of antibiotics (ATB) in human and veterinary medicine has contributed with the emergence of multidrug-resistant bacteria. Anthropogenic activities related to the use of these compounds have supported the selection and/or dissemination, as well as, the acquisition of genetic elements, mainly in aquatic environments. Currently, main antibiotics affected by antibacterial resistance are quinolones/fluoroquinolones and beta-lactams. The emergence and spread of species exhibiting resistance to these agents have been favored by versatile mobilization and acquisition of genetic determinants responsible for the phenotype. Antimicrobial resistance is a public health issue, which it has restricted therapeutic choices. In Brazil, monitoring of multidrug-resistant bacteria has been focused on human medicine, and indeed, studies about the spread of MR phenotypes in the environment are sporadic. Therefore, this study aims to monitor the spread of bacteria with MDR profile in aquatic urban environments and public drinking water sources in the state of São Paulo, and to identify the predominance of specific genotypes and their genetic similarity with clinical isolates. The resistance profile will be characterized by qualitative (Kirby-Bauer) and quantitative (MIC) susceptibility test according to CLSI recommendations using antibiotics for human and veterinary use. The production of acquired beta-lactamases (i.e., ESBL, KPC, MBL) will be evaluated by using specific inhibitors (clavulanic acid, phenylboronic acid and EDTA). Moreover, genes carried on plasmids conferring resistance to extended-spectrum cephalosporins and carbapenems or, encoding resistance to quinolones (PMQR: aac(6 ')-1b-cr, OqxAB, qepA, qnr), will be identified by PCR and direct sequencing. The genetic similarity of MDR species will be evaluated by ERIC-PCR and/or PFGE in comparison with clinical MR bacterial strains, previously characterized as endemic in Brazilian medical centers. For carbapenemase-producing isolates ancestor analysis will be conducted by MLST. Additionally, the phylogenetic groups of virulence will be identified in isolates of Escherichia coli. These results will allow a better understanding on the current status of the antimicrobial resistance in bacterial isolates recovered from aquatic environments and public drinking water sources, showing the environmental and clinical impact of the overuse and misuse of compounds with antimicrobial activity, identifying public places with greatest potential for dissemination and/or transmission of these agents, both for humans and other animals, including related ecosystems, in the most urbanized region of Brazil. (AU)