Emergence of Multidrug-resistance Bacteria Isolated of Drinking Water, Groundwater and Hospital Wastewater in Southern Benin: Antibiotic Resistance Profile and Resistomes Determination

Abstract Background: The environment plays an important role in the dissemination of multidrug resistant bacteria, especially through the aquatic ecosystem, which is made up of liquid hospital effluents, rivers, but also spring water and drinking water. This study aims to determinate resistomes in some aquatic matrices in southern Benin.Methods: These samples were filtered through a membrane 0.22 µm thick. After filtration, the membrane was deposited on Muëller Hinton agar. Then the colonies resulting from this subculture were subjected to a microbiological examination by the conventional method. The antibiotic sensitivity test was carried out by the Kirby Bauer method according to the recommendations of the French Society of Microbiology. Resistance genes were looked for by standard PCR and the PCR products were used for agarose gel electrophoresis.Results: Of the 222 water samples collected, 265 bacterial strains were isolated, the majority of which were strains of Coagulase Negative Staphylococcus (CNS) with 37.74% (n = 100), followed by strains of Klebsiella pneumoniae (21.89%; n = 58), Escherichia coli (10.57%; n = 28). All isolated gram-negative bacilli strains are multidrug resistant with resistance of all strains to amoxicillin, ampicillin and amoxicillin + clavulanic acid. Of the 15 resistance genes sought in the genome of Gram-negative bacilli strains, only 8 were detected, namely the TEM, SHV, CTX-M15, VIM, NDM, SUL1, SUL2 and AADA genes. Strong resistance of CNS strains to amoxicillin, oxacillin and cefoxitin was observed. The Mec A gene was detected in all CNS strains. While the Van A and Van B genes were only detected in strains isolated from drinking water in sachets collected from producers and street sellers.Conclusion: These results show the dissemination of resistance genes in the aquatic ecosystem of Benin and once again confirms the urgency of a global fight against antimicrobial resistance.