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Full-Text Articles in Life Sciences

Use Of Organic Acid Mixtures Containing 2-Hydroxy-4-(Methylthio) Butanoic Acid (Hmtba) To Mitigate Salmonella Enterica, Shiga Toxin-Producing Escherichia Coli (Stec) And Aspergillus Flavus In Pet Food Kibbles, Aiswariya Deliephan, Janak Dhakal, Bhadriraju Subramanyam, Charles G. Aldrich Feb 2023

Use Of Organic Acid Mixtures Containing 2-Hydroxy-4-(Methylthio) Butanoic Acid (Hmtba) To Mitigate Salmonella Enterica, Shiga Toxin-Producing Escherichia Coli (Stec) And Aspergillus Flavus In Pet Food Kibbles, Aiswariya Deliephan, Janak Dhakal, Bhadriraju Subramanyam, Charles G. Aldrich

Department of Food Science and Technology: Faculty Publications

Post-processing operations of extruded pet food kibbles involve coating the product with fats and flavorings. These processes increase the risk for cross-contamination with food-borne pathogens such as Salmonella and Shiga toxin-producing Escherichia coli (STEC), and mycotoxin-producing molds such as Aspergillus spp. after the thermal kill step. In this study, the antimicrobial effects of two types of organic acid mixtures containing 2-hydroxy-4-(methylthio) butanoic acid (HMTBa), Activate DA™ and Activate US WD-MAX™, against Salmonella enterica, STEC and Aspergillus flavus when used as a coating on pet food kibbles were evaluated. Using canola oil and dry dog digest as fat and flavor …


A Review Of Shiga-Toxin Producing Escherichia Coli (Stec) Contamination In The Raw Pork Production Chain, Manirul Haque, Joseph M. Bosilevac, Byron D. Chaves Jul 2022

A Review Of Shiga-Toxin Producing Escherichia Coli (Stec) Contamination In The Raw Pork Production Chain, Manirul Haque, Joseph M. Bosilevac, Byron D. Chaves

Department of Food Science and Technology: Faculty Publications

Epidemiological evidence of Shiga toxin-producing Escherichia coli (STEC) infections associated with the consumption of contaminated pork highlight the need for increased awareness of STEC as an emerging pathogen in the pork supply chain. The objective of this review is to contribute to our understanding of raw pork products as potential carriers of STEC into the food supply. We summarize and critically analyze primary literature reporting the prevalence of STEC in the raw pork production chain. The reported prevalence rate of stx-positive E. coli isolates in live swine, slaughtered swine, and retail pork samples around the world ranged from 4.4 …


Formation Of Escherichia Coli O157: H7 Persister Cells In The Lettuce Phyllosphere And Application Of Differential Equation Models To Predict Their Prevalence On Lettuce Plants In The Field, Daniel S. Munther, Michelle Q. Carter, Claude V. Aldric, Renata Ivanek, Maria T. Brandl Jan 2020

Formation Of Escherichia Coli O157: H7 Persister Cells In The Lettuce Phyllosphere And Application Of Differential Equation Models To Predict Their Prevalence On Lettuce Plants In The Field, Daniel S. Munther, Michelle Q. Carter, Claude V. Aldric, Renata Ivanek, Maria T. Brandl

Mathematics and Statistics Faculty Publications

American Society for Microbiology. Escherichia coli O157:H7 (EcO157) infections have been recurrently associated with produce. The physiological state of EcO157 cells surviving the many stresses encountered on plants is poorly understood. EcO157 populations on plants in the field generally follow a biphasic decay in which small subpopulations survive over longer periods of time. We hypothesized that these subpopulations include persister cells, known as cells in a transient dormant state that arise through phenotypic variation in a clonal population. Using three experimental regimes (with growing, stationary at carrying capacity, and decaying populations), we measured the persister cell fractions in culturable EcO157 …


Development Of A Bacteriophage-Based Portable Biosensor For The Detection Of Shiga-Toxin Producing Escherichia Coli (Stec) Strains In Food And Environmental Matrices, Irwin A. Quintela May 2018

Development Of A Bacteriophage-Based Portable Biosensor For The Detection Of Shiga-Toxin Producing Escherichia Coli (Stec) Strains In Food And Environmental Matrices, Irwin A. Quintela

Electronic Theses and Dissertations

A fast and reliable on-site foodborne pathogens screening can reduce the incidence of foodborne illnesses, hospitalizations and economic loss. It can also circumvent conventional laboratory-based tests with minimal sample treatments and shorter turnaround time. Rapid detection of biological hazards has been largely dependent on immunological agents (ie antibodies). Antibodies are expensive to manufacture and experience cross-reactivity, instability with shorter shelf life. Our aim was to improve the screening process of Shiga-toxin producing Escherichia coli (STEC) strains in food and environmental matrices by developing a novel, inexpensive handheld bacteriophage-based amperometric biosensor that can directly detect live STEC cells.This biosensor development began …


The Survival Of Various Pathogenic Organisms In Fats And Oils, Kelsey Ellen Lamb Jan 2017

The Survival Of Various Pathogenic Organisms In Fats And Oils, Kelsey Ellen Lamb

Theses and Dissertations--Animal and Food Sciences

The research within this thesis sought to determine the ability of various animal derived fats and plant derived oils to support the survival of several pathogenic cocktails over a multitude of storage times. The Salmonella study explored the survival rate of a four strain Salmonella cocktail in beef tallow, pig lard, duck fat, coconut oil, and extra virgin olive oil over seven days at 26˚C and 37˚C storage. The animal fats and the coconut oil supported the survival of the bacteria until the conclusion of the study. The Shiga-toxin producing Escherichia coli study explored the survival rate of a five …


Revisiting The Stec Testing Approach: Using Espk And Espv To Make Enterohemorrhagic Escherichia Coli (Ehec) Detection More Reliable In Beef, Sabine Delannoy, Byron D. Chaves, Sarah A. Ison, Hattie E. Webb, Lothar Beutin, Jose Delaval, Isabelle Billet, Patrick Fach Jan 2016

Revisiting The Stec Testing Approach: Using Espk And Espv To Make Enterohemorrhagic Escherichia Coli (Ehec) Detection More Reliable In Beef, Sabine Delannoy, Byron D. Chaves, Sarah A. Ison, Hattie E. Webb, Lothar Beutin, Jose Delaval, Isabelle Billet, Patrick Fach

Department of Food Science and Technology: Faculty Publications

Current methods for screening Enterohemorrhagic Escherichia coli (EHEC) O157 and non-O157 in beef enrichments typically rely on the molecular detection of stx, eae, and serogroup-specific wzx or wzy gene fragments. As these genetic markers can also be found in some non-EHEC strains, a number of “false positive” results are obtained. Here, we explore the suitability of five novel molecular markers, espK, espV, ureD, Z2098, and CRISPRO26:H11 as candidates for a more accurate screening of EHEC strains of greater clinical significance in industrialized countries. Of the 1739 beef enrichments tested, 180 were positive for both stx and eae genes. Ninety (50%) …


Inactivation Of Escherichia Coli O157:H7 And Shiga Toxin Producing E. Coli (Stec) Throughout Beef Summer Sausage Production And The Use Of High Pressure Processing As An Alternative Intervention To Thermal Processing, Eric L. Oliver Dec 2015

Inactivation Of Escherichia Coli O157:H7 And Shiga Toxin Producing E. Coli (Stec) Throughout Beef Summer Sausage Production And The Use Of High Pressure Processing As An Alternative Intervention To Thermal Processing, Eric L. Oliver

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Escherichia coli O157:H7 and six additional serogroups of Shiga Toxin-producing E. coli (STEC-7) have been implicated in foodborne illness outbreaks related to fermented sausage products and are considered adulterants by the USDA-FSIS. The objective of this study was to evaluate high pressure processing (HPP) as an alternative to thermal treatment to reduce STEC-7 meeting the USDA-FSIS performance standards (5.0-log reduction). A rifampicin-resistant, non-pathogenic E. coli (surrogate) cocktail, was used in manufacturing testing. Sausages were fermented at ~42.2°C, slowly increased to 54.4°C internal temperature, cold showered, and chilled for 6 hours. Sampling occurred post-fermentation (PF; pH 5.0), internal temperature 48.9°C (I-48.9°C), …


The Influence Of The Bovine Fecal Microbiota On The Shedding Of Shiga Toxin-Producing Escherichia Coli (Stec) By Beef Cattle, Nirosh D. Aluthge May 2015

The Influence Of The Bovine Fecal Microbiota On The Shedding Of Shiga Toxin-Producing Escherichia Coli (Stec) By Beef Cattle, Nirosh D. Aluthge

Department of Food Science and Technology: Dissertations, Theses, and Student Research

During the past three decades, Shiga toxin-producing E.coli (STEC) have emerged as an important food safety concern. Although initially E. coli O157 was the main focus, recent outbreaks and resulting investigations have shown that certain non-O157 STEC are as much a threat to food safety as their O157 counterparts. To the beef industry, STEC have been of particular concern due to the frequent association of beef and beef products as vehicles of STEC infection. As a result, along with E. coli O157, six non-O157 STEC serogroups (known as the ‘big six’) are now regulated as adulterants in certain raw beef …


Shiga Toxin-Producing Escherichia Coli In Meat: A Preliminary Simulation Study On Detection Capabilities For Three Sampling Methods, Julie Couton, David Marx, John Luchaansky, Randall Phebus, Anna Porto-Fett, Nicholas Sevart, Manpreet Singh, Harshavardhan Thippareddi Jan 2015

Shiga Toxin-Producing Escherichia Coli In Meat: A Preliminary Simulation Study On Detection Capabilities For Three Sampling Methods, Julie Couton, David Marx, John Luchaansky, Randall Phebus, Anna Porto-Fett, Nicholas Sevart, Manpreet Singh, Harshavardhan Thippareddi

Conference on Applied Statistics in Agriculture

Contamination by Shiga Toxin-producing Escherichia coli (STEC) is a continuing concern for meat production facility management throughout the United States. Several methods have been used to detect STEC during meat processing, however the excessive experimental cost of determining the optimal method is rarely feasible. The objective of this preliminary simulation study is to determine which sampling method (Cozzini core sampler, core drill shaving, and N-60 surface excision) will better detect STEC at varying levels of contamination present in the meat. 1000 simulated experiments were studied using a binary model for rare occurrences to find the optimal method. We found that …


Transfer And Survival Of Microorganisms To Produce From Surface Irrigation Water, Stuart Jamison Gorman Aug 2014

Transfer And Survival Of Microorganisms To Produce From Surface Irrigation Water, Stuart Jamison Gorman

Masters Theses

Surface water irrigation sources are widely used for fruit and vegetable crop production in the United States. Surface water is inherently prone to direct and indirect contamination with animal fecal material. Hence, the microbial quality of surface water sources can be highly variable. Water used for irrigation is considered a common source for produce contamination. In addition to this, fruits and vegetables are commonly consumed fresh or minimally processed, thus emphasizing the need for preventative measures in production of fresh produce. This study will examine transfer from naturally contaminated irrigation water to cantaloupes using drip and overhead spray irrigation methods. …