Date of Defense
15-4-2025 8:00 AM
Location
F3- 120
Document Type
Dissertation Defense
Degree Name
Doctor of Philosophy in Cellular and Molecular Biology
College
COS
Department
Biology
First Advisor
Dr. Sunil Mundra
Keywords
Antimicrobial resistance (AMR), Antibiotic resistance genes, Metagenome, Microbial communities, Sewage wastewater.
Abstract
Antimicrobial resistance (AMR) is a global health worry, which makes the treatment of infectious diseases difficult by compromising the effectiveness of antimicrobial medications. This issue got worsen by the use of antibiotics without proper prescription and care during the time of COVID-19. At that time more than 78% of patients were prescribed with the use of medications like azithromycin and cephalosporins. The urban wastewater systems like wastewater treatment plants (WWTPs), hospital effluents, and residential wastewater were found to be bursting with antibiotic-resistant bacteria (ARB) and resistance genes (ARGs). This research used advanced metagenomics and LC-MS/MS techniques for the examination of ARBs, irregularities of antibiotics and unique dynamics of ARGs throughout different wastewater sources in the United Arab Emirates (UAE). The samples were collected from three different sources including WWTPs, hospital wastewater and residential communities for the estimation of resistance due to the interactions among microbial taxa and ARGs. The techniques of solid-phase extraction (SPE) and LC-MS/MS were implied to investigate the variability of antibiotics, whereas metagenomics identified the profiles of ARGs by means of databases like CARD and ResFinder. The bioinformatics tools like Kraken and Bracken were used for the composition of the microbial communities determining impact of taxonomic groupings for spreading ARGs. Moreover, links between ARGs, microbial taxa, and environmental variables were evaluated by using statistical and network analyses. The major outcomes of the study show that the most common antibiotics are cefuroxime, vancomycin, and ciprofloxacin, with the highest amounts of ciprofloxacin found in hospital wastewater. Significant taxonomic groups like as Flavobacteriales, Sphingobacteriales, and Planctomycetales were discovered through metagenomics and bioinformatics tools helping in breaking the organic materials and spreading ARGs. The dominant ARGs like blaTEM, blaCTX-M, and tetA were identified in hospital wastewater and WWTPs. In WWTPs the stage of primary effluent (PE) showed the maximum bacterial richness, while returned activated sludge (RAS) displayed different kinds of resistant bacteria like Aeromonas sobria and Escherichia coli. The presence of multidrug-resistant microorganisms (MDR) in the samples of AS and RAS underscores their critical part as major ARGs reservoirs. Overall, the analyses show the role of wastewater systems in spreading ARGs and ARBs. The ineffectiveness of WWTPs for removing ARGs from wastewater emphasize the need for better monitoring of wastewater with refined treatment tools and techniques to limit the prevalence of AMR. This study dictates a comprehensive understanding of AMR emergence and its environmental effects in the area by the combination LC-MS/MS and metagenomic techniques. The results feature the correlation between the resistance and microbial networks, delivering important evidence for devising the strategies for fighting AMR and protecting public health.
Included in
ANTIMICROBIAL RESISTANCE (AMR) EMERGENCE IN SEWAGE WASTEWATER: AN INVESTIGATION BASED ON ADVANCED GENOMICS METHODS
F3- 120
Antimicrobial resistance (AMR) is a global health worry, which makes the treatment of infectious diseases difficult by compromising the effectiveness of antimicrobial medications. This issue got worsen by the use of antibiotics without proper prescription and care during the time of COVID-19. At that time more than 78% of patients were prescribed with the use of medications like azithromycin and cephalosporins. The urban wastewater systems like wastewater treatment plants (WWTPs), hospital effluents, and residential wastewater were found to be bursting with antibiotic-resistant bacteria (ARB) and resistance genes (ARGs). This research used advanced metagenomics and LC-MS/MS techniques for the examination of ARBs, irregularities of antibiotics and unique dynamics of ARGs throughout different wastewater sources in the United Arab Emirates (UAE). The samples were collected from three different sources including WWTPs, hospital wastewater and residential communities for the estimation of resistance due to the interactions among microbial taxa and ARGs. The techniques of solid-phase extraction (SPE) and LC-MS/MS were implied to investigate the variability of antibiotics, whereas metagenomics identified the profiles of ARGs by means of databases like CARD and ResFinder. The bioinformatics tools like Kraken and Bracken were used for the composition of the microbial communities determining impact of taxonomic groupings for spreading ARGs. Moreover, links between ARGs, microbial taxa, and environmental variables were evaluated by using statistical and network analyses. The major outcomes of the study show that the most common antibiotics are cefuroxime, vancomycin, and ciprofloxacin, with the highest amounts of ciprofloxacin found in hospital wastewater. Significant taxonomic groups like as Flavobacteriales, Sphingobacteriales, and Planctomycetales were discovered through metagenomics and bioinformatics tools helping in breaking the organic materials and spreading ARGs. The dominant ARGs like blaTEM, blaCTX-M, and tetA were identified in hospital wastewater and WWTPs. In WWTPs the stage of primary effluent (PE) showed the maximum bacterial richness, while returned activated sludge (RAS) displayed different kinds of resistant bacteria like Aeromonas sobria and Escherichia coli. The presence of multidrug-resistant microorganisms (MDR) in the samples of AS and RAS underscores their critical part as major ARGs reservoirs. Overall, the analyses show the role of wastewater systems in spreading ARGs and ARBs. The ineffectiveness of WWTPs for removing ARGs from wastewater emphasize the need for better monitoring of wastewater with refined treatment tools and techniques to limit the prevalence of AMR. This study dictates a comprehensive understanding of AMR emergence and its environmental effects in the area by the combination LC-MS/MS and metagenomic techniques. The results feature the correlation between the resistance and microbial networks, delivering important evidence for devising the strategies for fighting AMR and protecting public health.