September 2024
Issue 33
Consortium Brazil, Cameroon and Madagascar: think out the spread of antimicrobial and biocide resistance from the wastewater to the environment
The COVID-19 pandemic emerged during a period of significant concern about antimicrobial resistance (AMR), a major global health challenge. Hygiene measures to prevent COVID-19, coupled with antimicrobial use, may impact AMR evolution. Antimicrobials and biocides used in hospitals and communities enter wastewater treatment plants (WWTPs) and can end up in natural systems, leading to pollution of water ecosystems with residues and antimicrobial-resistant bacteria (ARB). This increases AMR spread, posing indirect risks to human and animal health.
In low- and middle-income countries like Cameroon and Madagascar, untreated wastewater is often discharged directly into rivers and streams due to non-functional WWTPs. In Brazil, existing WWTPs do not completely eliminate antimicrobials and biocides, contributing to AMR spread in surface waters. These contaminated water bodies are used for recreational activities and irrigation, further spreading AMR. In slums, the lack of WWTPs leads to direct contamination of water bodies, exacerbating the problem.
Studies on AMR spread in the environment, particularly in Europe, Asia, and the USA, have mostly focused on resistance characterization at specific sites, considering the selection pressure from environmental antimicrobials. The impact of COVID-19 on ARB persistence and spread remains undocumented.
The COV-AMR consortium (Cameroon, Madagascar and Brazil) aims to evaluate the impact of the COVID-19 pandemic on the spread of antimicrobials and biocide resistance in the environment. From January to June 2022, monthly water sampling was conducted in healthcare facilities treating COVID-19 patients and control sites to screen for multidrug-resistant bacteria, analyze resistance determinants, and identify genetic relationships using whole-genome sequencing. Antimicrobial and biocide residues were quantified using liquid chromatography-mass spectrometry. The water microbiome was analyzed with the Ion Torrent platform and QIIME2 tool. The presence of SARS-CoV-2 was investigated by RT-qPCR.
The study showed that during the COVID-19 pandemic, effluents from hospitals and urban areas in Cameroon, Brazil, and Madagascar facilitated AMR and biocide resistance spread in the environment. This exposure risks native bacteria acquiring resistance genes and populations facing hard-to-treat infections. Authorities must ensure WWTPs are functional to eliminate microbial flora and neutralize antimicrobial residues. Populations using contaminated water should observe strict hygiene. Governments should enforce regulations on hospital and municipal wastewater management, with periodic assessments and reporting of antimicrobial residues and resistance determinants.
The results of the study will help to raise public awareness of antimicrobial residue contamination and antimicrobial resistance, and alert people to the need to protect the environment and health.
Armelle Leslie Megueya, Ariane Nzouankeu, Centre Pasteur du Cameroun, Cameroon
Nazareno Scaccia, Joyce Vanessa da Silva Fonseca, Ester Cerdeira Sabino, Anderson Vicente de Paula, Maria Cássia Mendes-Correa, Silvia Figueiredo Costa, Institute of Tropical Medicine, University of São Paulo, Brazil.
Tiavina Rasolofoarison, Luc Hervé Samison, Charles Merieux Center of Infectious Disease, Madagascar.
Leonard de Vinci Kanda, Nilo José Coelho Duarte, Hospital das Clinicas HCFMUSP, University of São Paulo, Brazil
Maria Tereza Pepe Razzolini, School of Public Health of University of São Paulo, Brazil