Abstract
River systems in developing and emerging countries are often fragmented relative to land and waste management in their catchment. The impact of inconsistent waste management and releases is a major challenge in water quality management. To examine how anthropogenic activities and estuarine effects impact water quality, we characterised water conditions, in-situ microbiomes, profiles of faecal pollution indicator, pathogenic and antibiotic resistant bacteria in the River Melayu, Southern Malaysia. Overall, upstream sampling locations were distinguished from those closer to the coastline by physicochemical parameters and bacterial communities. The abundances of bacterial DNA, total E. coli marker genes, culturable bacteria as well as antibiotic resistance ESBL-producing bacteria were elevated at upstream sampling locations especially near discharge of a wastewater oxidation pond. Furthermore, 85.7% of E. faecalis was multidrug-resistant (MDR), whereas 100% of E. cloacae, E. coli, K. pneumoniae were MDR. Overall, this work demonstrates how pollution in river estuaries does not monotonically change from inland towards the coast but varies according to local waste releases and tidal mixing. We also show that surrogate markers, such dissolved oxygen, Bacteroides and Prevotella abundances, and the rodA qPCR assay for total E. coli, can identify locations on a river that deserve immediate attention to mitigate AMR spread through improved waste management.
Highlights
Antimicrobial resistance (AMR) poses a serious global threat of growing concern to human, animal, and environment health
Presumptive bacteria on respective selective agar plates were randomly isolated from Enterococcus faecium agar and HiCromeTM Coliform agar supplemented with antibiotics of each sam pling location for further antimicrobial susceptibility testing
Higher ammonia concentration was observed at M3 (5.32 ± 4.03 mg/L), which is closer to the sewage treatment plant (STP) discharge outlet, while other organic nutrients such as total nitrogen, total phosphorus and anions were generally low along the length of the river
Summary
Antimicrobial resistance (AMR) poses a serious global threat of growing concern to human, animal, and environment health. In Southeast Asia (SEA), thousands of estuarine communities rely on river water for sustaining their livelihoods, mainly via fisheries, coastal farming and tourism. Such economic activities form an important waterfood nexus, which drives regional socioeconomic progress (El-Hifnawi and Blancas, 2014; Mrozik et al, 2019; Pangare et al, 2014). Microbial abundances, communities, virulence factors, faecal indicator bacteria (FIB), multidrug-resistant (MDR) ESBL-producing bacteria and their resistance mechanisms were systematically characterised versus waste sources. The study highlights the value of a multi-pronged approach which combines culture-based quantification of faecal indicator and multidrug-resistant bacteria with gene-specific quantitative PCR and MinION next-generation sequencing to identify microbiome induced fragmentation and AMR sources in the river. The overall data shows how variable river water quality can be, even over relatively short reaches, due to different land uses, inconsis tent waste management, tidal mixing and anthropogenic activities
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
