Publications by authors named "Ahmed E Yousef"

Shiga toxin-producing Escherichia coli (STEC), a significant cause of foodborne illnesses, is often associated with the consumption of fresh produce, including alfalfa sprouts. This study was executed to determine how quickly STEC grows, adapts, and colonizes alfalfa sprouts during production and storage, and whether the pathogen's virulence and infectious doses are affected by physiological adaptation to sprouts as an environment. A reporter STEC O157:H7 EDL933 strain was developed to track the transcription of eae, a virulence gene involved in colonizing human intestinal enterocytes.

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  • * In a study conducted in Northwest Ethiopia from June 2022 to August 2023 across 58 dairy farms, 362 samples were tested for NTS, resulting in detection of 28 isolates (7.7%), with S. Uganda being the most prevalent serovar.
  • * The study found that 100% of NTS isolates had the invA virulence gene, 21.4% had spvC, and a high proportion (89.3%) were resistant to at least
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  • - Lactic acid bacteria are important for making fermented foods and can produce antimicrobial substances like bacteriocins.
  • - This text discusses the genomes of six lactic acid bacteria strains isolated from artisanal cheeses that have the genes needed to produce antimicrobial compounds.
  • - The six strains are from various genera, which indicates diversity in the sources and potential for different antimicrobial properties.
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Background: Antimicrobial resistance (AMR) is among the top public health concerns in the globe. Estimating the prevalence of multidrug resistance (MDR), MDR index (MDR-I) and extended-spectrum beta-lactamase (ESBL)-producing lactose fermenting Enterobacteriaceae (LFE) is important in designing strategies to combat AMR. Thus, this study was designed to determine the status of MDR, MDR-I and ESBL-producing LFE isolated from the human-dairy interface in the northwestern part of Ethiopia, where such information is lacking.

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is a versatile opportunistic pathogen which causes a variety of acute and chronic human infections, some of which are associated with the biofilm phenotype of the pathogen. We hypothesize that defining the intracellular metabolome of biofilm cells, compared to that of planktonic cells, will elucidate the metabolic pathways and biomarkers indicative of biofilm inception. Disc-shaped stainless-steel coupons (12.

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Ozone is often used as an antimicrobial agent at the final step in purified water processing. When used in purified bottled water manufacturing, residual ozone should not exceed 0.4 mg/L, per US-FDA regulations.

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Lytic bacteriophages are promising biocontrol agents against pathogenic bacteria for food and therapeutic applications. Investigating the feasibility of combining phage and physical lethal agents, such as heat, as an effective hurdle combination could lead to beneficial applications. The current research was initiated to compare the thermal inactivation kinetics of a lytic phage (Escherichia phage OSYSP) and its host (Shiga toxin-producing Escherichia coli O157:H7 EDL933), considering they have different critical thermal targets in their structures.

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serovar Enteritidis (SE) remains a frequent cause of foodborne illnesses associated with the consumption of contaminated hen eggs. Such a food-pathogen association has been demonstrated epidemiologically, but the molecular basis for this association has not been explored. Comparative genomic analysis was implemented to decipher the phylogenomic characteristics, antimicrobial resistance, and virulence potential of eggs-associated SE.

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Bacteriophage and gaseous ozone are evolving as meritorious alternatives to conventional sanitizers in food postharvest applications. Here, we investigated the efficacy of sequential treatments of a lytic bacteriophage and gaseous ozone, during vacuum cooling of fresh produce, against Escherichia coli O157:H7. Spinach leaves were spot-inoculated with 10-10 CFU g E.

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Biofilms are intricate multicellular structures created by microorganisms on living (biotic) or nonliving (abiotic) surfaces. Medically, biofilms often lead to persistent infections, increased antibiotic resistance, and recurrence of infections. In this review, we highlighted the clinical problem associated with biofilm infections and focused on current and emerging antibiofilm strategies.

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Biofilm formation in food processing environment and within equipment increases the risk of product spoilage and contamination with pathogens. Cleaning-in-place (CIP) operations are useful in removing soils and in sanitizing processing equipment, including eliminating biofilms. However, CIP is a resource-intensive process, particularly in the usage of chemical detergents, heat, and sanitizers.

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Thermal pasteurization of shell eggs, at various time-temperature combinations, has been proposed previously and implemented industrially. This study was conducted to determine if shell egg heating rate, which varies with different pasteurization implementations, alters the Salmonella enterica serovar Enteritidis response to different stresses or expression of virulence. Shell eggs, containing Salmonella Enteritidis in yolk, were subjected to a low (2.

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The coronavirus disease 2019 (COVID-19) has resulted in tremendous human and economic losses around the globe. The pandemic is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a virus that is closely related to SARS-CoV and other human and animal coronaviruses. Although foodborne diseases are rarely of pandemic proportions, some of the causative agents emerge in a manner remarkably similar to what was observed recently with SARS-CoV-2.

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Industrial production of paenibacillin, and similar rare antimicrobial peptides, is hampered by low productivity of the producing microorganisms and lack of efficient methods to recover these peptides from fermentor or bioreactor end products. Preliminary data showed that paenibacillin was preferentially partitioned in foam accumulated during growth of the producer, Paenibacillus polymyxa, in aerated liquid media. This research was initiated to improve the production and recovery of paenibacillin in bioreactors by maximizing partitioning of this antimicrobial agent in the collected foam.

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Contribution of food vehicles to pathogenicity of disease-causing microorganisms is an important but overlooked research field. The current study was initiated to reveal the relationship between virulence of serovar Enteritidis and egg yolk as a hosting medium. Mice were orally challenged with Enteritidis cultured in egg yolk or tryptic soy broth (TSB).

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Production of some antimicrobial peptides by bacterial producers is a resource-intensive process, thus, using inexpensive growth media and simplifying antimicrobial extraction and down-stream processing are highly desirable. Acid whey, a dairy industry waste, is explored as a medium for production of broad-spectrum antimicrobials from selected bacteriocinogenic bacteria. Neutralized and yeast extract-supplemented acid whey was suitable for production of antimicrobials by four tested strains, but OSY-EC was the most prolific antimicrobial producer.

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Some serovars are frequently associated with disease outbreaks in low-moisture foods (LMF) due to their ability to adapt efficiently to desiccation stress. These serovars are often persistent during food processing. Disruption of these resistance responses was accomplished previously using the membrane-active lipopeptide, paenibacterin.

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  • * Researchers used PCR screening, genome mining, and liquid chromatography to analyze Bacillus velezensis GF610, revealing its two-component lantibiotic structure and its antimicrobial effectiveness against several harmful bacteria.
  • * The findings suggest that amyloliquecidin GF610 could have valuable applications in food, agriculture, and medicine, and the analytical methods used could help in finding more similar compounds in the future.
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  • - Some strains of Salmonella can thrive in low-water activity foods, leading to outbreaks, so new methods to make these foods safer are needed.
  • - Natural antimicrobial food additives like carvacrol and thymol were found to increase potassium leakage in these resistant strains, making them more vulnerable to drying and heat processing.
  • - Experiments showed that carvacrol effectively reduced Salmonella populations in milk through spray-drying and freeze-drying, suggesting it could be a powerful tool in improving food safety.
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serovar Enteritidis ODA 99-30581-13 is a relatively heat-resistant strain isolated from shell eggs. The strain has a 4,777,965-bp genome sequence (52.1% GC content) that was predicted to encode 4,455 proteins, including heat stress response proteins and stress response regulators; these may be involved in its heat resistance.

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serovar Livingstone 1236H was isolated originally from peanut butter and represents a health risk in low-moisture foods. The current work presents the strain's genome sequencing results, which show a 4,824,729-bp genome sequence and 4,435 protein coding sequences, including some that are involved in adaptation to low-moisture environments.

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An strain, designated OSY-EGY, was previously isolated from artisanal cheese. In this work, comparative genomic and phenotypic analyses were utilized to assess the safety characteristics and probiotic traits of the bacterium. The comparative genomic analysis revealed that the strain is distantly related to potentially pathogenic spp.

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The novel strain OSU-PECh-69 was isolated from provolone cheese. It produces antimicrobial agents having a molecular mass of 5 to 10 kDa that are active against Gram-positive and Gram-negative bacteria. The strain has a genome sequence of 3,057,669 bp, a GC content of 46.

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Bacteriophage OSY-STA is a new anti- phage that was isolated from a chicken farm in Ohio. It is a promising candidate for food safety applications, considering its efficiency in infecting several serovars. The current work presents its genomic characteristics.

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  • - Health professionals are looking for effective alternatives to current antimicrobials due to increasing resistance among pathogens, prompting a study to find new bacteriocins from lactic acid bacteria (LAB) for use as preservatives.
  • - A LAB strain called OSY-TC318, isolated from Turkish cheese, was discovered to inhibit multiple pathogenic bacteria, and was identified using genome-guided mass spectrometry (MS) and genomic analysis.
  • - The study identified a novel lantibiotic produced by OSY-TC318, named paraplantaricin TC318, detailing its molecular characteristics and highlighting its potential as a new antimicrobial agent distinct from existing ones.
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