Publications by authors named "Absar Alum"

Viral detection methodologies used for wastewater-based epidemiology (WBE) studies have a broad range of efficacies. The complex matrix and low viral particle load in wastewater emphasize the importance of the concentration method. This study focused on comparing three commonly used virus concentration methods: polyethylene glycol precipitation (PEG), immuno-magnetic nanoparticles (IMNP), and electronegative membrane filtration (EMF).

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Electrochlorination has gained research interest for its potential application as decentralized water treatment. A number of studies have displayed promising efficiency for water disinfection. However, a comprehensive comparison of in situ electrodisinfection to existing disinfection techniques, particularly under realistic water composition and flow rates, still needs additional research efforts.

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In drinking water distribution systems (DWDSs), pipe material and water temperature are some of the critical factors affecting the microbial flora of water. Six model DWDSs consisting of three pipe materials (galvanized steel, copper, and PEX) were constructed. The temperature in three systems was maintained at 22 °C and the other 3 at 32 °C to study microbial and elemental contaminants in a 6-week survey using 16S rRNA next-generation sequencing (NGS) and inductively coupled plasma-optical emission spectrometry (ICP-OES).

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Inactivation of human respiratory viruses in air and on surfaces is important to control their spread. Exposure to germicidal ultraviolet (UV-C) light damages viral nucleic acid rendering them non-infectious. Most of the recent viral inactivation studies have not considered potential artifacts caused by interactions between UV-C light and culture media used to suspend and deposit virus on surfaces.

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is an environmental pathogen that is responsible for respiratory disease and is a common causative agent of water-related outbreaks. Due to their ability to survive in a broad range of environments, transmission of legionellosis is possible from a variety of sources. Unfortunately, a disproportionate amount of research that is devoted to studying the occurrence of in environmental reservoirs is aimed toward cooling towers and premise plumbing.

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Pathogenic bacteria pose a health threat and operational challenge in drinking water. UV-C light-emitting diodes (UV-C LEDs) are becoming a competitive disinfection technology but are limited by their small irradiation area. Side-emitting optical fibers (SEOFs) can serve as a UV-C LED light delivery technology for reactors or tubing.

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Bacteriophages, or phages, are receiving increasing interest as recognition tools for the design of bioactive surfaces. However, to maintain the activity of surface-bound phages, the immobilization strategy must provide the right orientation and not compromise the phages' integrity. The objectives of this study were to characterize the phage sorption capacity and the immobilized phage activity for aminated silica particles functionalized with T4 phages.

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Nanoparticles have emerged as significant environmental contaminants and their impact has been studied using laboratory strains of bacteria. This study focuses on investigating the response of environmental isolate and laboratory strains of E. coli to 50 and 100 nm size of copper nanoparticles (CuNPs).

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This study elucidates the potential risk posed by Legionella during aquifer recharge practices. Experiments were conducted using pilot-scale column simulating infiltration of bacterial surrogate and pathogen, E. coli and Legionella pneumophila, under central Arizona recharge basin conditions.

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Rapid bacterial detection using biosensors is a novel approach for microbiological testing applications. Validation of such methods is an obstacle in the adoption of new bio-sensing technologies for water testing. Therefore, establishing a quality assurance and quality control (QA/QC) plan is essential to demonstrate accuracy and reliability of the biosensor method for the detection of in drinking water samples.

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Background: The modern built environment (BE) design creates unique ecological niches ideal for the survival and mutual interaction of microbial communities. This investigation focused on the synergistic relations between Legionella and the fungal species commonly found in BEs and the impact of these synergistic relationships on the survival and transmission of Legionella.

Methods: A field study was conducted to identify the types and concentrations of fungi in BEs.

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Bacteroides genetic markers have been widely used to identify fecal pollution of water originating from human and animal sources. Many of the assays currently used for detecting human-specific Bacteroides produce false positive results. The focus of this study was to develop a microbial source tracking (MST) tool box strategy for differentiating Bacteroides from human and animal sources.

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There remains a need for rapid, specific and sensitive assays for the detection of bacterial indicators for water quality monitoring. In this study, a strategy for rapid detection of Escherichia coli in drinking water has been developed. This strategy is based on the use of the substrate 4-methylumbelliferyl-β-d-glucuronide (MUG), which is hydrolyzed rapidly by the action of E.

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To examine the impact of environmental factors on Legionella in drinking water distribution systems, the growth and survival of Legionella under various conditions was studied. When incubated in tap water at 4 °C, 25 °C, and 32 °C, L. pneumophila survival trends varied amongst the temperatures, with the stable populations maintained for months at 25 °C and 32 °C demonstrating that survival is possible at these temperatures for extended periods in oligotrophic conditions.

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Epidemiological evidence suggesting driving cars to be a risk factor for legionellosis has prompted public health studies to investigate vehicle windshield washer fluid as a novel transmission source of this disease. The goal of the current study was to investigate whether or not windshield washer fluid could serve as a potential source of transmission for Legionella. A wide variation in the survival of L.

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The impact of fluctuation in chlorine residual on actinomycetes and the production of 2-methylisoborneol (MIB) were studied in cast-iron and PVC model distribution systems. Actinomycetes were spiked in each system and continued operation for a 12-day non-chlorine experiment, resulting in no changes in actinomycetes and MIB concentrations. Three cyclic chlorination events were performed and chlorine residuals were maintained as follows: 1.

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This study was conducted to investigate the microbiological quality of raw cow's milk in a collection center in the city of Mashhad, Iran. A total of 19 raw cow's milk samples were collected and simultaneously analyzed for male-specific (F(+)) coliphage and Escherichia coli using culture-based methods and for enteric viruses by reverse transcriptase semi-nested PCR using primer sets specific for human norovirus Group I (HNV-GI), human norovirus Group II (HNV-GII), and enteroviruses (EV). Seven out of 19 (36.

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The objective of this study was to find out the impact of environmental conditions on the survival of intestinal parasites on environmental surfaces commonly implicated in the transmission of these parasites. The study was performed by incubating Cryptosporidium and Giardia (oo)cysts on environmentally relevant surfaces such as brushed stainless steel, formica, ceramic, fabric, and skin. Parallel experiments were conducted using clean and soiled coupons incubated under three temperatures.

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For land application, biosolids are classified as Class A or Class B based on the levels of bacterial, viral, and helminths pathogens in residual biosolids. The current EPA methods for the detection of these groups of pathogens in biosolids include discrete steps. Therefore, a separate sample is processed independently to quantify the number of each group of the pathogens in biosolids.

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Bacteroides molecular markers have been used to identify human fecal contamination in natural waters, but recent work in our laboratory confirmed cross-amplification of several human-specific Bacteroides spp. assays with fecal DNA from fish. For identification of unique molecular markers, Bacteroides from human (n = 4) and fish (n = 7) fecal samples were cultured and their identities were further confirmed using Rapid ID 32A API strips.

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The objective of the study was to identify the enzymatic-biochemical (enz-bio) signatures of Escherichia coli and Salmonella for rapid detection of these bacteria in drinking water biofilms. The relative potency of lipophilic, glucosidic, and proteolytic activities in biofilms containing single bacterial species and mixture of different bacterial was used to identify the enz-bio signatures of Escherichia coli and Salmonella. The enz-bio signatures identified were: Lipophilic < Glucosidic < Proteolytic (for Escherichia coli); and Glucosidic = Lipophilic < Proteolytic (for Salmonella).

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Background: Giardia sp is a major cause of diarrheal illness worldwide, and millions of people are infected each year. Rapid methods to determine the infectivity and virulence of isolates are critical for the development of intervention strategies to control the transmission of Giardia sp cysts, which occurs through contaminated surfaces, food, and water. However, determining the viability, infectivity, and virulence of Giardia sp cysts using molecular methods is a technical challenge because of the lack of a cell culture model.

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The lack of efficient methods for concentrating viruses in water samples leads to underreporting of viral contamination in source water. A novel strategy for viral concentration was developed using the expression of target virus receptors on bacterial cells. Poliovirus type 1, the most studied enterovirus, was used as a surrogate for enteric viruses.

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Background: Globally, disinfectants are widely used to intervene in the dissemination of Cryptosporidium oocysts. However, extensive investigations of oocyst inactivation by various disinfectants are not feasible due to the limitations imposed by animal infectivity methods. Molecular techniques provide an alternative strategy; however, non-metabolic genes have been used as markers for determining viability/infectivity.

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Biosolids contain a wide variety of organic contaminants that are known for their ability to inhibit PCR. During sample processing, these contaminants are coconcentrated with microorganisms. Elevated concentrations of these compounds in concentrates render samples unsuitable for molecular applications.

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