Publications by authors named "Fawzy Hashem"

Article Synopsis
  • Alternative irrigation waters can contain harmful bacterial foodborne pathogens that may contaminate fruits and vegetables, making detection crucial for food safety.
  • A study compared qPCR (real-time PCR) with traditional culture methods for identifying these pathogens, examining factors like water type, season, and sample volume over two years across multiple sites.
  • The findings revealed that qPCR detection had reasonable predictive values, with better agreement observed in spring and summer, particularly in reclaimed and pond water compared to river water, indicating water type influences detection accuracy.
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The quantity of seafood imported and produced by domestic aquaculture farming has increased. Recently, it has been reported that multidrug-resistant (MDR) Typhimurium may be associated with seafood. However, information is limited to the antimicrobial resistance, virulence properties, and genetic diversity of recovered from imported and domestic seafood.

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Enteric bacterial pathogen levels can influence the suitability of irrigation water sources for fruits and vegetables. We hypothesize that stable spatial patterns of Salmonella enterica and Listeria monocytogenes levels may exist across surface water sources in the Mid-Atlantic U.S.

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is a Gram-negative, rod-shaped, facultative anaerobic, and non-spore-forming bacterium that belongs to the family of Enterobacteriaceae and is the causative agent for typhoid/paratyphoid fever and salmonellosis. causes the highest amount of foodborne illness among bacteria at 15.5 cases per 100,000 and causes an estimated 410,000 antibiotic-resistant infections each year in the U.

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Irrigation water sources have been shown to harbor foodborne pathogens and could contribute to the outbreak of foodborne illness related to consumption of contaminated produce. Determining the probability of and the degree to which these irrigation water sources contain these pathogens is paramount. The purpose of this study was to determine the prevalence of Salmonella enterica and Listeria monocytogenes in alternative irrigation water sources.

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Article Synopsis
  • Enteric viruses (EVs) are a major cause of foodborne illnesses, and their persistence in the environment poses contamination risks for agricultural crops, especially through nontraditional irrigation sources like reclaimed and surface waters.
  • A 17-month study focused on detecting specific human EVs and indicators in Mid-Atlantic region irrigation waters, using real-time quantitative PCR to assess viral presence and environmental factors.
  • The results indicated higher detection rates of EVs and PMMoV in reclaimed water compared to surface water, showing significant correlations with water salinity and highlighting the need for microbiological analysis to ensure food safety.
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Urea-nitrogen (N) is commonly applied to crop fields, yet it is not routinely monitored despite its association with reduced water quality and its ability to increase toxicity of certain phytoplankton species. The purpose of this work was to characterize temporal fluctuations in urea-N concentrations and associated environmental conditions to infer sources of urea-N in agricultural drainage ditches. Physicochemical properties and N forms in ditch waters were measured weekly during the growing seasons of 2015-2018.

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Article Synopsis
  • Climate change is straining freshwater resources, necessitating the search for safe, alternative water sources for irrigation of fresh produce.
  • A 26-month study analyzed bacterial contamination levels in water from various sites (like creeks, tidal rivers, and ponds) to assess their safety for irrigation, with many samples showing high levels of total coliforms and enterococci.
  • Only a few sites met food safety standards, but implementing recommended measures could enable all tested water sources to safely be used for irrigation within 2 days, highlighting the importance of this research for food safety and agricultural practices.
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Agricultural drainage ditches represent a major source of nutrient pollution. Shifts in nitrogen source and use of animal manures have changed the bacterial composition both in species of bacteria and their abundance in agricultural ditches. This change affects how nitrogen is being cycled and potentially the final forms of available nutrients.

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Article Synopsis
  • This study investigated the presence of Salmonella enterica and Listeria monocytogenes in various irrigation water sources over a two-year period.
  • Researchers found that river waters had higher levels of S. enterica compared to pond or reclaimed waters, while non-tidal river sites showed significantly more L. monocytogenes during cooler months.
  • The study also highlighted that filtering larger water volumes (10 L) was much more effective at detecting these pathogens than smaller samples (1 L and 0.1 L).
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Agricultural water withdrawals account for the largest proportion of global freshwater use. Increasing municipal water demands and droughts are straining agricultural water supplies. Therefore, alternative solutions to agricultural water crises are urgently needed, including the use of nontraditional water sources such as advanced treated wastewater or reclaimed water, brackish water, return flows, and effluent from produce processing facilities.

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  • * Over a year, researchers collected 510 water samples from various sources, finding that 2.35% contained STEC and 9.0% contained atypical enteropathogenic E. coli (aEPEC).
  • * The most commonly detected virulence factor gene was eae, and STEC isolates were primarily found in specific water sites, suggesting possible post-treatment contamination in reclaimed water.
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Article Synopsis
  • A quenching agent, like sodium thiosulfate, is added to reclaimed water samples to stop chlorine from killing off bacteria during collection.
  • A study compared 16S rRNA sequencing data from quenched and non-quenched water samples.
  • Results indicated that the quenching process did not adversely affect the bacterial profiles analyzed through sequencing methods.
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The quality of irrigation water used to cultivate produce that is consumed raw is an important issue with regard to food safety. In this study, the microbiological quality of potential irrigation water sources in Arizona was evaluated by testing for the presence of indicator and pathogenic bacteria. Reclaimed water samples were collected from two wastewater treatment plants and return flow samples were collected from two drainage canals and one return flow pond.

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  • Untreated biological soil amendments of animal origin (BSAAO), like manure, can harbor harmful bacteria that pose food safety risks, and this study investigates how different types of BSAAO affect the survival of these pathogens in agricultural fields.
  • The research, conducted across multiple sites in the Mid-Atlantic U.S. from 2011 to 2015, analyzed 324 survival profiles and found that factors such as season, amendment type, and soil moisture content significantly influenced how long these pathogens could survive in the soil.
  • Results showed that poultry litter had the longest survival duration for the pathogens compared to other amendments, emphasizing the need to consider specific management practices and soil properties when determining safe intervals between manure application and crop harvesting to reduce foodborne illness
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Urea-N is linked to harmful algal blooms in lakes and estuaries, and urea-N-based fertilizers have been implicated as a source. However, the export of urea-N-based fertilizers appears unlikely, as high concentrations of urea-N are most commonly found in surface waters outside periods of fertilization. To evaluate possible autochthonous production of urea-N, we monitored urea-N released from drainage ditch sediments using mesocosms.

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This study's goal was to ascertain the effectiveness of a commercially available Salmonella bacteriophage during ground chicken production focusing on: water source, different Salmonella serovars, and time. Salmonella-free boneless, skinless chicken meat was inoculated with 4.0 Log CFU/cm2 of either a cocktail of 3 Salmonella isolates derived from ground chicken (GC) or a cocktail of 3 Salmonella strains not isolated from ground chicken (non-GC).

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Salmonella enterica associated with consumption of cucumbers ( Cucumis sativus ) has led to foodborne outbreaks in the United States. Whole and fresh-cut cucumbers are susceptible to S. enterica contamination during growing, harvesting, and postharvest handling.

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Studies of harmful algal blooms and associated urea concentrations in the Chesapeake Bay and in coastal areas around the globe strongly suggest that elevated urea concentrations are associated with harmful algal blooms. The observed increased frequency and toxicity of these blooms in recent decades has been correlated with increased agricultural use of N inputs and increased use of urea as a preferred form of commercial N. This rainfall simulation study sought to assess the potential for different N fertilizers and manures to contribute to urea in runoff from a Coastal Plain soil on the Eastern Shore of Maryland.

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The aim of this study was to investigate the microbiological quality of six types of fresh produce obtained from three retail stores located on the Eastern Shore of Maryland, USA. A total of 414 samples representing basil, cilantro, lettuce, scallion, spinach, and parsley were analyzed for total aerobic bacteria (APC), total coliforms, Escherichia coli, and three pathogenic bacteria (E. coli O157:H7, Listeria monocytogenes, and Salmonella), using standard methods.

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Salmonella and Campylobacter are major causes of foodborne related illness and are traditionally associated with consuming undercooked poultry and/or consuming products that have been cross contaminated with raw poultry. Many of the isolated Salmonella and Campylobacter that can cause disease have displayed antimicrobial resistance phenotypes. Although poultry producers have reduced on-the-farm overuse of antimicrobials, antimicrobial resistant Salmonella and Campylobacter strains still persist.

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Herbaceous bioenergy crops, including sorghum, switchgrass, and miscanthus, were evaluated for their potential as phytoremediators for the uptake of phosphorus in the Delmarva Peninsula and their subsequent conversion to biofuel intermediates (bio-oil) by fast pyrolysis using pyrolysis-gas chromatography/mass spectroscopy. Four cultivars of sorghum, five cultivars of switchgrass and one miscanthus (Miscanthus × giganteus) were grown in soils with two different levels of poultry manure (PM) applications. Little variation was seen in phosphorus uptake in the two different soils indicating that the levels of available phosphorus in the soil already saturated the uptake ability of the plants.

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Rainfall is a driving force for the transport of environmental contaminants from agricultural soils to surficial water bodies via surface runoff. The objective of this study was to characterize the effects of antecedent soil moisture content on the fate and transport of surface applied commercial urea, a common form of nitrogen (N) fertilizer, following a rainfall event that occurs within 24 hr after fertilizer application. Although urea is assumed to be readily hydrolyzed to ammonium and therefore not often available for transport, recent studies suggest that urea can be transported from agricultural soils to coastal waters where it is implicated in harmful algal blooms.

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