National Survey of Stream Water Quality Revealing Threats to Antibio-Resistant Bacteria, Antibiotic Residues and Heavy Metals in Benin

Document Type : Original Research Paper


1 Research Unit in Applied Microbiology and Pharmacology of Natural Substances, Research Laboratory in Applied Biology, Polytechnic School of Abomey-Calavi, University of Abomey-Calavi, 01 P.O. Box 2009, Cotonou, Benin

2 Laboratory of Monitoring and Environmental Studies, Ministry of the Living Environment and Sustainable Development, Benin

3 Department of Chemistry, University of Ibadan, Ibadan, Nigeria

4 Laboratory of Biology and Molecular Typing in Microbiology, Faculty of Sciences and Techniques, University of Abomey-Calavi, P. O. Box 1604, Cotonou, Benin

5 Laboratory of Geology, Mines and Environment, Faculty of Sciences and Techniques, University of Abomey-Calavi, Benin

6 Laboratory of Genetics and Biotechnology, Faculty of Sciences and Techniques, University of Abomey-Calavi, Benin



Benin’s waterways are affected by several forms of pollution that are linked in particular to anthropic activities. This study aims to detect the presence of antibiotic residues, the frequency of antibiotic resistant bacteria and the levels of heavy metals in Benin’s waterways. 160 surface water samples from streams in Benin were collected. They were filtered by the membrane filtration method, then incubated on different media. The isolated bacterial species were identified by API 20E gallery and specific biochemical tests. After detection of the resistance profile of the latter, the antibiotic residues were quantified in the samples by the ELISA technique on plate and the physicochemical analyses were performed by Multi 3630 IDS SET KS2 multimeter. Finally, heavy metal levels were detected by the MERCK test kit method specific to each metal. The bacterial species mostly identified were Klebsiella pneumoniae (56.59%), Klebsiella spp. (18.68%), Enterobacter spp. (12.63%). The most abundant resistance of bacterial strains was to amoxicillin + clavulanic acid (92%), followed by metronidazole (86%). Metronidazole was the antibiotic with the highest residue concentration in the samples (6.578 to 6.829 µg/L), followed by ciprofloxacin (2.142 to 9.299 µg/L). Benin streams contain heavy metals such as mercury (0.454±0.129 µg/L), lead (0.040±0.50 mg/L), zinc (6.120±16.017 mg/L), nickel (0.155±0.233 mg/L) and cadmium (0.154±0.132 mg/L). The analysis of the physico-chemical parameters showed that, apart from electrical conductivity, all parameters comply with Beninese and World Health Organization standards. Actions must be taken to clean up these rivers to preserve the integrity of aquatic ecosystems in Benin.


Abdel-Baki, A.S., Dkhil, M.A. and Al-Quraishy, S. (2011). Bioaccumulation of some heavy metals in tilapia fish relevant to their concentration in water and sediment of Wadi Hanifah, Saudi Arabia. Afr J Biotechnol. 10(13):2541-2547.
Ajima, M.N.O., Nnodi, P.C., Ogo, O.A., Adaka, G.S., Osuigwe, D.I. and Njoku, D.C. (2015). Bioaccumulation of heavy metals in Mbaa River and the impact on aquatic ecosystem. Environ Monit Assess.187:768. 
Azaiez, M.B., Tilouche, L., Kebir, J., Ketata, S. and Chaouch, C. (2019). Profil épidémiologique et bactériologique des infections intra-abdominales. Médecine et Maladies Infectieuses. 49(4):S111.
Ben Moussa, A., Chahlaoui, A. and Rour, El H. (2012). Évaluation de la pollution physico-chimique des eaux de l’Oued Khoumane (Moulay Idriss Zerhoun, Maroc). Int J Biol Chem Sci. 6(6):7096-7111.
Collignon, P., Beggs, J.J., Walsh, T.R., Gandra, S. and Laxminarayan, R. (2018). Anthropological and socioeconomic factors contributing to global antimicrobial resistance: a univariate and multivariable analysis. Lancet Planet Heal. 2(9):e398-e405. 
Croix, N.R. (2019). Chevauchement des vulnérabilités : les impacts du changement climatique sur les besoins humanitaires. Oslo:Croix-Rouge norvégienne.
Danner, M.C., Robertson, A., Behrends, V. and Reiss, J. (2019). Antibiotic pollution in surface fresh waters: Occurrence and effects. Sci Total Environ. 664:793-804.
Dimon, F., Dovonou, F., Adjahossou, N., Chouti, W., Mama, D., Alassane, A. and Boukari, M. (2014). Caractérisation physico-chimique du lac Ahémé (Sud Bénin) et mise en relief de la pollution des sédiments par le plomb, le zinc et l’arsenic. J. Soc. Ouest-Afr. Chim, 37, 36-42. (2014) Caractérisation physico-chimique du lac Ahémé (Sud Bénin) et mise en relief de la pollution des sédiments par le plomb, le zinc et l’arsenic. J Soc Ouest-Afr Chim. 037:36- 42.
Djenadi, K., Zhang, L., Murray, A.K. and Gaze, WH. (2018). Résistance aux carbapénèmes chez des bactéries isolées des milieux sol et eau en Algérie Tourillon de résistance antimicrobienne globale. 15:262-267.
Dougnon, V., Chabi, Y., Koudokpon, H., Agbankpe, J., Sefounon, R., Alle, D., Bankole, H. and Baba-Moussa, L. (2020). Prescription of antibiotics as a source of emerging antibiotic resistance: Knowledge, attitudes, and practices of medical staff in the Dassa-Glazoué and Savalou-Bantè’s health zones (Benin, West Africa). International Journal of One Health. 6(1): 34-40.
Everaert, G., De Rijcke, M., Lonneville, B., Janssen, CR., Backhaus, T., Mees, J., van Sebille, E., Koelmans, A.A., Catarino, A.I., Vandegehuchte, M.B. (2020). Risks of floating microplastic in the global ocean. Environmental Pollution. 267:115499.
Gombima, G.N. (2021). Prévalence de syndrome gastritique à Helicobacter Pylori: Étude menée au laboratoire provincial de santé publique du sud-Ubangi (Hopital Général de Référence de Gemena). International Journal of Innovation and Applied Studies. 33(2):280-291.
Gotkowska-Płachta, A., Gołaś, I., Korzeniewska, E., Koc, J. and Rochwerger, A. (2015). Evaluation of the distribution of fecal indicator bacteria in a river system depending on different types of land use in the southern watershed of the Baltic Sea. Environ Sci Pollut Res. 23(5):4073-4085. 
Hounkpè, J.B., Kelome, N.C., Lawani, R.A. and Adechina, A.R.M.A. (2017). Etat des lieux de la pollution des écosystemes aquatiques au Bénin (Afrique de l’ouest). Status of aquatic ecosystem pollution in Benin (West africa). Larhyss Journal. 30:149-171.
Ichola, O.D., Dougnon, V.T., Koudokpon, C.H., Agbankpe, A.J., Deguenon, E., Ayena, A.C., Soclo, H.H. (2021). Assessment of the bacterial pollution and detection of antibiotic resistance genes in Benin: case of the hydrographic channel complex Cotonou-Nokoue’s lake. Journal of Environmental and Public Health. 2021 ID 6664816. 
Janjić, J., Ivanović, J., Marković, R., Starčević, M., Bošković, M., Đorđević, V. and Baltić, M. (2015). Metal concentration in muscle tissue of carp and pike from different fish ponds in Belgrade area. J Agric Sci Technol. 5:429-436.
Jovanović, D.A., Marković, R.V., Teodorović, V.B., Šefer, D.S., Krstić, M.P., Radulović, S.B., Ivanović Ćirić, J.S., Janjić, J.M., Baltić, M.Ž. (2017). Determination of heavy metals in muscle tissue of six fish species with different feeding habits from the Danube River, Belgrade public health and environmental risk assessment. Environ Sci Pollut Res. 24:11383-11391.
Jovičić, K., Nikolić, DM., Višnjić-Jeftić, Ž., Đikanović, V., Skorić, S., Stefanović, S.M., Lenhardt, M., Hegediš, A., Krpo-Ćetković, J., and Jarić, I. (2015). Mapping differential elemental accumulation in fish tissues: assessment of metal and trace element concentrations in wels catfish (Silurus glanis) from the Danube River by ICP-MS. Environ Sci Pollut R. 22:3820-3827.
Kehrig, H.A., Seixas, T.G., Malm, O., Di Beneditto, A.P. and Rezende, C.E. (2013). Mercury and selenium biomagnification in a Brazilian coastal food web using nitrogen stable isotope analysis: a case study in an area under the influence of the Paraiba do Sul River plume. Mar Pollut Bull.75:283-290.
Khalfallah, A., Dounya, M. and Ikhlas, S. (2021). Degrés de contamination et isolement des Bactéries multi-résistantes aux Antibiotiques dans l’eau de l’Oued Seybouse «Guelma, Nord-Est de l’Algérie». 
Koudokpon, H., Dougnon, V., Lougbegnon, C., Déguénon, E., Mousse, W., Agbankpe, A.J., Avodagbe, G., Saidou, S., Bankole, H., Baba-Moussa, L. (2021). Antibiotic resistance profile and resistance determination of bacteria isolated from water in Southern Benin. Journal of Advances in Microbiology. 21(4):91-105.
Kubera, L. (2021). Spread patterns of antibiotic resistance in faecal indicator bacteria contaminating an urbanized section of the Brda river. Microbial Ecology., 81:592-600.
Marti, E., Variatza, E. and Balcazar, J. L. (2014). The role of aquatic ecosystems as reservoirs of antibiotic resistance. Trends Microbiol. 22:36–41. 
Michael, I., Rizzo, L., McArdell, CS., Manaia, CM., Merlin, C., Schwartz, T., Dagot, C., Fatta-Kassinos D. (2013) Urban wastewater treatment plants as hotspots for the release of antibiotics in the environment: A review. Water Res. 47:957-995.
Montalvo, C., Aguilar, CA., Amador, LE., Cerónl, JG., Cerón, RM., Anguebes, F. and Cordova, A.V. (2014). Metal contents in sediments (Cd, Cu, Mg, Fe, Mn) as indicators of pollution of Palizada River, Mexico. Environment and Pollution. 3(4):89-98.
Morel, M-C., Spadini, L., Brimo, K. and Martins, J.M.F. (2014). Speciation study in the sulfamethoxazole– copper–pH–soil system: Implications for retention prediction. Sci Total Environ. 481:266-273.
Olaoye, O.A. and Onilude, AA. (2009). Évaluation de la qualité microbiologique de l’eau potable en sachet dans l’ouest du Nigeria et son importance pour la santé publique. Santé publique. 123(11):729-734.
Peralta, D.A. (2016). Etude du devenir et de l’impact des antibiotiques à l’échelle d’un bassin versant : application au bassin versant du Katari (Bolivie). Environnement et Société Université Grenoble Alpes.
Rodier, J., Legube, B., Merlet, N. and Brunet, R. (2009). L’analyse de l’Eau. (9 edn) Dunod Paris.
Rodriguez-Mozaz, S., Chamorro, S., Marti, E., Huerta, B., Gros, M., Sànchez-Melsió, A., Borrego, C.M., Barceló, D., Balcázar, J.L. (2015). Occurrence of antibiotics and antibiotic resistance genes in hospital and urban wastewaters and their impact on the receiving river. Water Research. 69:234-242.
Sani, M.M., Lokrou, A., Abodo, J., Dago, K.P. and Kouassi, F. (2018). Émergence de souches d’entérobactéries résistantes aux fluoroquinolones dans les cultures des plaies diabétiques compliquées d’ostéites à Abidjan (Côte-d’Ivoire). Health Sciences and Disease. 19(1).
The European Committee on Antimicrobial Susceptibility Testing (EUCAST) (2019) Breakpoint tables for interpretation of MICs and zone diameters. Version 9.0. 
Tissera,S. and Lee, S.M. (2013). Isolation of extended spectrum betalactamase (ESBL) producing bacteria from urban surface waters in Malaysia. Malays J Med Sci. 20(3):14-22.
Tshibanda, J.B., Malumba, A.M., Mpiana, P.T., Mulaji, C.K., Otamonga, JP., and Poté, J.W. (2021). Influence du bassin versant sur l’accumulation des métaux lourds dans les sédiments des rivières urbaines en conditions tropicales : Cas des rivières N’djili et Lukaya à Kinshasa République Démocratique du Congo Écologie des bassins versants et environnement.3:30-37.
Verep, B., Multu, C., Apaydin, G. and Cevik, U. (2012). The trace element analysis in freshwater fish species, water and sediments in Iyidere stream (Rize-Turkey). Pak J Biol Sci. 15:658-665.
WHO. (2017). Système mondial de surveimlance de la résistance aux antimicrobiens. Manuel de mise en œuvre.
Zhang, S.X., Zhang, Q.Q., Liu, Y.S., Yan, X.T., Zhang, B., Xing, C., Zhao, J.L., Ying, G.G. (2020). Emission and fate of antibiotics in the Dongjiang River Basin, China: implications for antibiotic resistance risk. Sci Total Environ.712:136518. 
Zinsou, H.L., Attingli, A.H., Gnohossou, P., Adandedjan, D. and Laleye, P. (2016) Caractéristiques physico-chimiques et pollution de l’eau du delta de l’Ouémé au Bénin. Tourillon des biosciences appliquées. 97: 9163-9173.