Antibiotic resistance genes and viral genomes assessment in wastewater samples from cabo verde wastewater treatment plants
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Universidade de Cabo Verde, Faculdade de Ciências e Tecnologia, Zona K, Palmarejo - Praia, Ilha de Santiago, República de Cabo Verde, 7943-010, Cape Verde
Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901 Oeiras, Portuga
Publication date: 2023-04-26
Popul. Med. 2023;5(Supplement):A142
Background and Objectives:
Reusing treated wastewater is a sustainable and recommendable strategy, especially in a nation where water shortage is a major issue. As a result, increasing the use of treated wastewater in agriculture is a sine qua non condition. However, conventional wastewater treatment plants are sometimes ineffective in removing emerging microbiological contaminants such as resistant bacteria and antibiotic resistance genes, as well as human pathogenic viruses, and are thus considered sites of antibiotic resistance proliferation and spread. The aim of this study was to evaluate the presence of antibiotic-resistant bacteria/genes (ARB/ARG) as well as human-pathogenic viral genomes in water from wastewater treatment plants.

ARG and viral genomes were detected by multiplex qPCR methods in the influent and treated effluent of six WWTPs chosen in the islands of Cabo Verde. Meropenem or ciprofloxacin were added to a selective medium to help isolate bacteria resistant to these AB, and the EUCAST disc diffusion technique was used to analyse the AB resistance phenotypes of possibly pathogenic bacteria. Finally, we extracted plasmids (using a kit from Nzytech) from five prominent clones of each influente sample to analyse the variety of Adenovirus and Polyomavirus in Cape Verde.

Polyomavirus, adenovirus, norovirus GII, hepatitis A and hepatitis E genomes were detected at high concentrations (106 gc/L) in either the influent or effluent samples, as were carbapenem and fluoroquinolone resistance genes at concentrations of 1010 gc/L.

These findings indicate that conventional treatments currently being used in the investigated WWTPs are insufficient to effectively remove ARG and viral genomes, which highlights the need for the development and implementation of targeted treatments at full scale in the WWTPs so that the produced effluents can be safely discharged into the environment and/or recycled for uses like agricultural irrigation (ensuring food security).