Examinando por Autor "Perveen, Shabila"

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Evaluation of the potential risks of antibioticresistant bacteria and genes (ARBs & ARGs), and microplastics (MPs); and monitoring of their removal in water treatment processes
(Universidad Rey Juan Carlos, 2023) Perveen, Shabila
Antibiotic resistance poses a significant threat to global health, food security, and development. It has led to longer hospital stays, higher medical costs, and increased mortality rates [1]. Additionally, there is a concern over microplastics (MPs) in the environment. Plastics that end up in the environment stay for centuries and degrade into small pieces (< 5mm) called MPs. MPs are also produced deliberately and added to various products. At present, there is no allencompassing European legislation that deals with MPs. The existing proposition by the European Commission is to limit MPs under the REACH Regulation (EC No 1907/2006) [2]. MP pollution was also included in the European Union´s proposal by the Marine Strategy Framework Directive (MSFD,2008/56/EC) [3]. However, there are no prescribed minimal reductions for MPs, antibiotics, antibiotic-resistant bacteria (ARB), and antibiotic resistance genes (ARGs) in water and wastewater treatment guidelines [4]. MPs, ARB, and ARGs continue to persist as global pollutants in both natural and engineered water systems. Twelve bacterial families are included in the list of priority pathogens for antibiotic resistance [1]. The spread of ARB and ARGs through water is a matter of great concern and identifying the ARG carriers isolated in wastewater treatment plant (WWTP) effluent is critical in determining the potential threat to human health caused by antibiotic resistance. MPs in water bodies are considered a novel microbial niche with the potential to act as a vector for ARGs and pathogens to new environments, spreading the associated health risk across environmental compartments and the aquatic food-chain [5]. Wu et al. [6] studied the bacterial pathogens in MP biofilm and found that the MP biofilm had a distinctive resistome as compared to the rock and leaf particles in the same water matrix. Furthermore, ARGs in three pathogens were found in MP biofilm only, indicating ARG enrichment by MP biofilm as compared to natural particles. The MP biofilm has the potential to spread antibiotic resistance, alter marine bacterial communities and pose health hazards [7]. Therefore, there is a possibility of MP bound pathogens acquiring ARGs from the surrounding environment and traveling to remote environmental compartments. Previous studies also identified opportunistic pathogens in MP biofilm [8]. Furthermore, a potential connection is anticipated between WWTP derived bacteria and the intl1 abundance in the plastisphere. It could be due to the ability of even small amounts of sewage effluent to enhance the intl1 prevalence in freshwater biofilm without alteration of the ambient water microbial community [9]. The environmental factors along with the physicochemical properties of MPs are important in the determination of bacterial ecology in the MP biofilm.
Growth and prevalence of antibiotic-resistant bacteria in microplastic biofilm from wastewater treatment plant effluents
(Elsevier, 2022) Perveen, Shabila; Pablos, Cristina; Reynolds, Ken; Stanley, Simon; Marugán, Javier
It is accepted that Microplastic (MP) biofilms accumulates antibiotic-resistant bacteria (ARB) and antibiotic-resistant genes (ARGs) in water. ARB/ARGs and MPs are emerging pollutants of concern due to various associated health risks. The objective of this study was to 1) investigate the ARB community in a pilot-scale wastewater treatment plant (WWTP) effluent, 2) to study and visualize the ARB/ARGs in MP biofilm grown in WWTP effluent and tap water, and 3) to analyze microplastic adherent ARB/ARGs in the biofilm and planktonic ARB/ARGs in the filtrate under controlled conditions. Results indicated the dominance of Pseudomonas, Aeromonas, and Bacillus among isolated ARB in WWTP effluent. Representative resistance strains were incubated in 300 mL water containing commercial polystyrene beads of 300550 μm diameter (MP) in a series of batch experiments. Microbiological, molecular, and microscopic analyses were performed by enumeration, 16srRNA, real-time polymerase chain reaction (qPCR), and Field Emission-Scanning Electron Microscopy (FEG-SEM) techniques. The analyzed viable ARB indicated an increasing trend in MP biofilms between days 3 and 5. It further decreased on days 7 and 9. The prevalence of ARB in the filtrate and MP biofilm varied as a function of time and TOC level, while no significant impacts were observed for minor temperature variation, low antibiotic pressure, and increased MP mass with few exceptions. Relative abundance of ARGs (vanA, sul1) and integron integrase gene (intl1) in MP biofilm were significantly different across different TOC levels, time, and antibiotic pressure. ARGs and intl1 were detected in the MP biofilm in tap water and WWTP effluent on day 30.