Spatiotemporal variation in urban wastewater pollution impacts on river microbiomes and associated hazards in the Akaki Catchment, Addis Ababa, Ethiopia

In Addis Ababa and its environs, most urban wastewater is discharged into rivers without treatment. This study related urban wastewater characteristics to the prevalence of faecal, antibiotic resistant, and potentially pathogenic bacteria in rivers of the Akaki catchment across six locations, for th...

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Autores principales: Hiruy, A.M., Mohammed, J., Haileselassie, M. M., Acharya, K., Butte, G., Haile, Alemseged Tamiru, Walsh, C., Werner, D.
Formato: Journal Article
Lenguaje:Inglés
Publicado: Elsevier 2022
Materias:
Acceso en línea:https://hdl.handle.net/10568/119312
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author Hiruy, A.M.
Mohammed, J.
Haileselassie, M. M.
Acharya, K.
Butte, G.
Haile, Alemseged Tamiru
Walsh, C.
Werner, D.
author_browse Acharya, K.
Butte, G.
Haile, Alemseged Tamiru
Haileselassie, M. M.
Hiruy, A.M.
Mohammed, J.
Walsh, C.
Werner, D.
author_facet Hiruy, A.M.
Mohammed, J.
Haileselassie, M. M.
Acharya, K.
Butte, G.
Haile, Alemseged Tamiru
Walsh, C.
Werner, D.
author_sort Hiruy, A.M.
collection Repository of Agricultural Research Outputs (CGSpace)
description In Addis Ababa and its environs, most urban wastewater is discharged into rivers without treatment. This study related urban wastewater characteristics to the prevalence of faecal, antibiotic resistant, and potentially pathogenic bacteria in rivers of the Akaki catchment across six locations, for the dry and wet season. Spatiotemporal variation in bacterial hazards across the catchment was up to 6 log10 units. Cooccurrence of sewage pollution marker gene HF183 in all river samples testing positive for the Vibrio cholerae marker gene ompW, and high levels of these two genes in untreated wastewater, identified human sewage as the likely source of Vibrio cholerae hazards in the catchment. Levels of the marker genes rodA for E. coli, HF183 for human host associated Bacteroides, ciaB for Arcobacter, and ompW for Vibrio cholerae were all higher in the dry season than in the wet season. Marker gene gyrB for Pseudomonas aeruginosa was not detected in the samples. From the sequencing data, notable bacterial genera in the dry season included wastewater pollution indicators Arcobacter and Aeromonas, whereas soil erosion may explain the greater prominence of Legionella, Vicinamibacter, and Sphingomonas during the wet season. Except for the most upstream location, all faecal coliform (FC) counts exceeded WHO standards of 1000 CFU/100 mL for unrestricted irrigation. Concerningly, 0.6–20% of FC had ESBL producing antimicrobial resistance traits. In conclusion, multiple bacterial hazards were of concern for river water users in the Akaki catchment, and elevated in the dry season, when the river water is being used for irrigation of vegetable fields that supply the markets of Addis Ababa. This reflects inadequate treatment and limited dilution of urban wastewater by the natural river flows during periods of low rainfall.
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spelling CGSpace1193122025-10-26T13:01:34Z Spatiotemporal variation in urban wastewater pollution impacts on river microbiomes and associated hazards in the Akaki Catchment, Addis Ababa, Ethiopia Hiruy, A.M. Mohammed, J. Haileselassie, M. M. Acharya, K. Butte, G. Haile, Alemseged Tamiru Walsh, C. Werner, D. municipal wastewater water pollution river water biological contamination bacteria faecal pollution faecal coliforms water quality standards antimicrobial resistance microbiological risk assessment extended spectrum beta-lactamases real time pcr surface water catchment areas irrigation effluents health hazards In Addis Ababa and its environs, most urban wastewater is discharged into rivers without treatment. This study related urban wastewater characteristics to the prevalence of faecal, antibiotic resistant, and potentially pathogenic bacteria in rivers of the Akaki catchment across six locations, for the dry and wet season. Spatiotemporal variation in bacterial hazards across the catchment was up to 6 log10 units. Cooccurrence of sewage pollution marker gene HF183 in all river samples testing positive for the Vibrio cholerae marker gene ompW, and high levels of these two genes in untreated wastewater, identified human sewage as the likely source of Vibrio cholerae hazards in the catchment. Levels of the marker genes rodA for E. coli, HF183 for human host associated Bacteroides, ciaB for Arcobacter, and ompW for Vibrio cholerae were all higher in the dry season than in the wet season. Marker gene gyrB for Pseudomonas aeruginosa was not detected in the samples. From the sequencing data, notable bacterial genera in the dry season included wastewater pollution indicators Arcobacter and Aeromonas, whereas soil erosion may explain the greater prominence of Legionella, Vicinamibacter, and Sphingomonas during the wet season. Except for the most upstream location, all faecal coliform (FC) counts exceeded WHO standards of 1000 CFU/100 mL for unrestricted irrigation. Concerningly, 0.6–20% of FC had ESBL producing antimicrobial resistance traits. In conclusion, multiple bacterial hazards were of concern for river water users in the Akaki catchment, and elevated in the dry season, when the river water is being used for irrigation of vegetable fields that supply the markets of Addis Ababa. This reflects inadequate treatment and limited dilution of urban wastewater by the natural river flows during periods of low rainfall. 2022-06 2022-04-12T18:48:51Z 2022-04-12T18:48:51Z Journal Article https://hdl.handle.net/10568/119312 en Open Access Elsevier Hiruy, A. M.; Mohammed, J.; Haileselassie, M. M.; Acharya, K.; Butte, G.; Haile, Alemseged Tamiru; Walsh, C.; Werner, D. 2022. Spatiotemporal variation in urban wastewater pollution impacts on river microbiomes and associated hazards in the Akaki Catchment, Addis Ababa, Ethiopia. Science of the Total Environment, 826:153912. [doi: https://doi.org/10.1016/j.scitotenv.2022.153912]
spellingShingle municipal wastewater
water pollution
river water
biological contamination
bacteria
faecal pollution
faecal coliforms
water quality standards
antimicrobial resistance
microbiological risk assessment
extended spectrum beta-lactamases
real time pcr
surface water
catchment areas
irrigation
effluents
health hazards
Hiruy, A.M.
Mohammed, J.
Haileselassie, M. M.
Acharya, K.
Butte, G.
Haile, Alemseged Tamiru
Walsh, C.
Werner, D.
Spatiotemporal variation in urban wastewater pollution impacts on river microbiomes and associated hazards in the Akaki Catchment, Addis Ababa, Ethiopia
title Spatiotemporal variation in urban wastewater pollution impacts on river microbiomes and associated hazards in the Akaki Catchment, Addis Ababa, Ethiopia
title_full Spatiotemporal variation in urban wastewater pollution impacts on river microbiomes and associated hazards in the Akaki Catchment, Addis Ababa, Ethiopia
title_fullStr Spatiotemporal variation in urban wastewater pollution impacts on river microbiomes and associated hazards in the Akaki Catchment, Addis Ababa, Ethiopia
title_full_unstemmed Spatiotemporal variation in urban wastewater pollution impacts on river microbiomes and associated hazards in the Akaki Catchment, Addis Ababa, Ethiopia
title_short Spatiotemporal variation in urban wastewater pollution impacts on river microbiomes and associated hazards in the Akaki Catchment, Addis Ababa, Ethiopia
title_sort spatiotemporal variation in urban wastewater pollution impacts on river microbiomes and associated hazards in the akaki catchment addis ababa ethiopia
topic municipal wastewater
water pollution
river water
biological contamination
bacteria
faecal pollution
faecal coliforms
water quality standards
antimicrobial resistance
microbiological risk assessment
extended spectrum beta-lactamases
real time pcr
surface water
catchment areas
irrigation
effluents
health hazards
url https://hdl.handle.net/10568/119312
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