Presence of antibiotic resistance genes and its association with antibiotic occurrence in Dilúvio River in southern Brazil

Juliana Bazzan Arsand; Rodrigo Barcellos Hoff; Louise Jank; Roberta Bussamara; Alexsandro Dallegrave; Fatima Menezes Bento; Livia Kmetzsch; Daiane Acosta Falção; Maria do Carmo Ruaro Peralba; Adriano de Araujo Gomes; Tânia Mara Pizzolato

doi:10.1016/j.scitotenv.2020.139781

Presence of antibiotic resistance genes and its association with antibiotic occurrence in Dilúvio River in southern Brazil

Sci Total Environ. 2020 Oct 10:738:139781. doi: 10.1016/j.scitotenv.2020.139781. Epub 2020 May 30.

Affiliations

¹ Programa de Pós-Graduação em Química, Instituto de Química, Universidade Federal do Rio Grande do Sul - UFRGS, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, RS, Brazil.
² Laboratório Nacional Agropecuário - LANAGRO/RS, Ministério da Agricultura, Pecuária e Abastecimento do Brasil, Estrada da Ponta Grossa 3036, 91780-580 Porto Alegre, RS, Brazil.
³ Departamento de Microbiologia, Imunologia e Parasitologia, ICBS/UFRGS, Rua Sarmento Leite 500, 90035-190 Porto Alegre, RS, Brazil.
⁴ Programa de Pós-Graduação em Química, Instituto de Química, Universidade Federal do Rio Grande do Sul - UFRGS, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, RS, Brazil; Centro de Biotecnologia. Av. Bento Gonçalves 9500, prédio 43421.
⁵ Programa de Pós-Graduação em Química, Instituto de Química, Universidade Federal do Rio Grande do Sul - UFRGS, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, RS, Brazil. Electronic address: tania.pizzolato@ufrgs.br.

PMID: 32526421
DOI: 10.1016/j.scitotenv.2020.139781

Abstract

It is known that antibiotics are widely used in human and veterinary medicine. In some countries the use is controlled, however few restrictions to their use are enforced in many countries. Antibiotics and their metabolites can reach the water bodies through sewage systems, especially in those countries with partial or absent wastewater treatment systems. The overuse and misuse of antibiotics has been linked with the increase of antibiotic resistant bacteria. The relation between the occurrence of antibiotics and resistance genes in surface waters has been widely studied worldwide evincing the great importance of this subject. In this work, a methodology for quantification of 40 antibiotics of 5 different classes, in river water, by SPE-LC-MS/MS was validated. Samples were taken during a two-year period from Dilúvio River, a stream that crosses the city of Porto Alegre (RS - Brazil) and receives in nature domestic effluent. The methodology met the requirements of validation, with Limit of Quantification varying from 20 ng L^-1 to 100 ng L^-1. A total of 48 samples was analyzed for the presence of antibiotics for two years. From the 40 antibiotics analyzed, 8 of them (Azithromycin, Cephalexin, ciprofloxacin, clindamycin, norfloxacin, sulfadiazine, sulfamethoxazole and trimethoprim) were present in all sampling points in the range of <LOQ to 344 ng L^-1. The occurrence of antibiotics resistance genes in the sampling points was determined using qPCR. Specific primers were utilized to detected resistance genes to the β-lactam cephalexin (bla_TEM gene), to the quilonones ciprofloxacin and norfloxacin (qnrS gene), to the macrolides azithromycin and clindamycin (ermB gene), and to the sulfonamides sulfadiazine and sulfamethoxazole (sulI gene), which were quantified the selected water samples. Quantitative PCR analysis revealed the presence of ARGs in all samples, with the highest concentration found for bla_TEM.

Keywords: Antibiotic resistant bacteria; Emerging contaminants; LC-MS/MS; Real time PCR; Surface waters.

MeSH terms

Anti-Bacterial Agents / pharmacology
Brazil
Chromatography, Liquid
Cities
Drug Resistance, Microbial / drug effects
Humans
Rivers*
Tandem Mass Spectrometry
Wastewater
Water Pollutants, Chemical / analysis*

Substances

Anti-Bacterial Agents
Waste Water
Water Pollutants, Chemical