Salmonella Prevalence and Quantification in Market Hog Lymph Nodes and Tonsils in Several Regions and Seasons of the United States.

Market hog lymph nodes (LNs) can contaminate carcasses with Salmonella, as well as ground and comminuted pork products. The objective of this study was to perform a qualitative and quantitative analysis of LNs from several regions and seasons in the United States to establish a Salmonella prevalence and concentration baseline. Six types of LNs (axillary, mesenteric, subiliac, tracheobronchial, superficial inguinal, prescapular), and tonsils were sampled from market hog carcasses from different regions (east, central, and west) and seasons (winter, spring, and summer/fall).

Survivability and thermal resistance of Salmonella and Escherichia coli O121 in wheat flour during extended storage of 360 days.

Foodborne pathogens like Salmonella and Escherichia coli O121 can endure the harsh low water activity (a) environment of wheat flour for elongated periods of time and can proliferate when hydrated for baking or other purposes. This study determined the survivability and thermal tolerance (D- and z-values) of Salmonella and Escherichia coli O121 in wheat flour and muffin batter (prepared from inoculated flour on the days of analyses) during the storage period of 360 days. The Salmonella and E.

Attachment of Shiga Toxin-Producing (STEC) to Pre-Chill and Post-Chill Beef Brisket Tissue.

Shiga toxin-producing (STEC) has caused numerous foodborne illness outbreaks where beef was implicated as the contaminated food source. Understanding how STEC attach to beef surfaces may inform effective intervention applications at the abattoir. This simulated meat processing conditions to measure STEC attachment to adipose and lean beef tissue.

Genotypic and Phenotypic Characterization of Antimicrobial Resistance Profiles in Non-typhoidal Strains Isolated From Cambodian Informal Markets.

Non-typhoidal is a pathogen of global importance, particularly in low and middle-income countries (LMICs). The presence of antimicrobial resistant (AMR) strains in market environments poses a serious health threat to consumers. In this study we identified and characterized the genotypic and phenotypic AMR profiles of 81 environmental strains isolated from samples from informal markets in Cambodia in 2018-2019.

Validation of post-harvest antimicrobial interventions to control Shiga toxin-producing Escherichia coli (STEC) on market hog carcass surfaces.

Although swine are less associated with STEC foodborne disease outbreaks, the potential for swine to serve as a source of STEC infections in human beings cannot be disregarded. This study compared eight USDA-approved antimicrobial intervention technologies to quantify their ability to reduce STEC contamination on market hog carcasses. Hogs were harvested to provide skin-on carcass sides, and eight sides (per three replications) were inoculated with a 7-strain STEC cocktail (ca.

Thermal inactivation of Salmonella during hard and soft cookies baking process.

This study validated a simulated commercial baking processes for hard and soft cookies to control Salmonella, and determined D- and z-values of 7-serotype Salmonella (Newport, Senftenberg, Tennessee, Typhimurium, and three isolates from dry pet food) cocktail in cookie doughs. Cookie doughs were prepared using flour mist-inoculated with the Salmonella cocktail. Hard and soft cookies were baked at 185 °C for 16 min and 165.

Shiga Toxin-Producing in Wheat Grains: Detection and Isolation by Polymerase Chain Reaction and Culture Methods.

Shiga toxin-producing (STEC) are major foodborne pathogens and seven serogroups, O26, O45, O103, O111, O121, O145, and O157, often called top-7 STEC, account for the majority of the STEC-associated human illnesses in the United States. Two Shiga toxins, Shiga toxins 1 and 2, encoded by 1 and 2 genes, are major virulence factors that are involved in STEC infections. Foodborne STEC infections have been linked to a variety of foods of both animal and plant origin, including products derived from cereal grains.

Draft Genome Sequences of Salmonella enterica subsp. Serotype IIIb_61:I,v:1,5,(7) Strains Isolated from Wheat Grains.

subsp. serotypes are primarily involved in reptile-associated salmonellosis in humans. Here, we report the draft genome sequences of three subsp.

Identification, Shiga toxin subtypes and prevalence of minor serogroups of Shiga toxin-producing Escherichia coli in feedlot cattle feces.

Shiga toxin-producing Escherichia coli (STEC) are foodborne pathogens that cause illnesses in humans ranging from mild to hemorrhagic enteritis with complications of hemolytic uremic syndrome and even death. Cattle are a major reservoir of STEC, which reside in the hindgut and are shed in the feces, a major source of food and water contaminations. Seven serogroups, O26, O45, O103, O111, O121, O145 and O157, called 'top-7', are responsible for the majority of human STEC infections in North America.

Prevalence of Salmonella enterica Isolated from Food Contact and Nonfood Contact Surfaces in Cambodian Informal Markets.

Abstract: The lack of hygiene and sanitation practices and insufficient infrastructure in Cambodian informal markets may increase the risk of food contamination, specifically raw vegetables, which in turn may increase the chances of contracting a foodborne disease. The aims of this study in informal markets in Cambodia were (i) to quantify the prevalence of Salmonella enterica based upon differences in season of the year (rainy versus dry), surface types (food contact surfaces versus nonfood contact surfaces), and location of vendors within the market (inside versus outside) and (ii) to characterize S. enterica serotype prevalence.

Investigating Salmonella enterica, Escherichia coli, and Coliforms on Fresh Vegetables Sold in Informal Markets in Cambodia†.

Abstract: Vegetables in Cambodia are commonly sold in informal markets lacking food safety standards and controls. Current data on microbial contamination of vegetables in Cambodian informal markets are limited. The purpose of this study was to investigate Salmonella enterica and indicator organisms (Escherichia coli and coliforms) on the surface of fresh vegetables sold in informal markets in Cambodia.

Draft Genome Sequences of 81 Salmonella enterica Strains from Informal Markets in Cambodia.

is an important global pathogen due to its contribution to human morbidity and death. The presence of in Southeast Asian informal markets is amplified by cross-contamination between market surfaces and food products. Here, we describe the draft genome sequences of 81 isolates from informal markets in Cambodia.

Hyperspectral imaging of common foodborne pathogens for rapid identification and differentiation.

Hyperspectral imaging (HSI) provides both spatial and spectral information of a sample by combining imaging with spectroscopy. The objective of this study was to generate hyperspectral graphs of common foodborne pathogens and to develop and validate prediction models for the classification of these pathogens. Four strains of , five strains of spp.

Evaluation of thermal inactivation parameters of Salmonella in whole wheat multigrain bread.

This study was conducted to validate a simulated commercial whole wheat multigrain bread baking process at 375 °F (190.6 °C) oven temperature for 35 min to inactivate Salmonella, and to determine the thermal inactivation parameters of a 7-serovar Salmonella cocktail in whole wheat multigrain bread dough. A ≥5-log CFU/g reduction in Salmonella population was achieved by 15 min, and no viable Salmonella was detected after enrichment plating by 16 min.

Validation of a nut muffin baking process and thermal resistance characterization of a 7-serovar Salmonella inoculum in batter when introduced via flour or walnuts.

This study was conducted to validate a commercial nut muffin baking process and to compare the survival of a 7-serovar Salmonella cocktail when contaminated via inoculated flour or walnuts. Enriched wheat flour or walnut pieces were mist inoculated with the Salmonella cocktail and dried back to the pre-inoculation weight, resulting in a Salmonella population level of 6.9 and 8.

Evaluation of post-fermentation heating times and temperatures for controlling Shiga toxin-producing cells in a non-dried, pepperoni-type sausage.

Coarse ground meat was mixed with non-meat ingredients and starter culture () and then inoculated with an 8-strain cocktail of Shiga toxin-producing (ca. 7.0 log CFU/g).

Validation of a Sequential Hide-On Bob Veal Carcass Antimicrobial Intervention Composed of a Hot Water Wash and Lactic Acid Spray in Combination with Scalding To Control Shiga Toxin-Producing Escherichia coli Surrogates.

Scalding of hide-on bob veal carcasses with or without standard scalding chemical agents typically used for hogs, followed by an 82.2°C hot water wash and lactic acid spray (applied at ambient temperature) before chilling, was evaluated to determine its effectiveness in reducing Shiga toxin-producing Escherichia coli surrogate populations. A five-strain cocktail of rifampin-resistant, nonpathogenic E.

Use of an Electrostatic Spraying System or the Sprayed Lethality in Container Method To Deliver Antimicrobial Agents onto the Surface of Beef Subprimals To Control Shiga Toxin-Producing Escherichia coli.

The efficacy of an electrostatic spraying system (ESS) and/or the sprayed lethality in container (SLIC) method to deliver antimicrobial agents onto the surface of beef subprimals to reduce levels of Shiga toxin-producing Escherichia coli (STEC) was evaluated. Beef subprimals were surface inoculated (lean side; ca. 5.

Validation of the baking process as a kill-step for controlling Salmonella in muffins.

This research investigates the potential risk of Salmonella in muffins when contamination is introduced via flour, the main ingredient. Flour was inoculated with a 3-strain cocktail of Salmonella serovars (Newport, Typhimurium, and Senftenberg) and re-dried to achieve a target concentration of ~8logCFU/g. The inoculated flour was then used to prepare muffin batter following a standard commercial recipe.

Validation of Baking To Control Salmonella Serovars in Hamburger Bun Manufacturing, and Evaluation of Enterococcus faecium ATCC 8459 and Saccharomyces cerevisiae as Nonpathogenic Surrogate Indicators.

This study was conducted to validate a simulated commercial baking process for hamburger buns to destroy Salmonella serovars and to determine the appropriateness of using nonpathogenic surrogates (Enterococcus faecium ATCC 8459 or Saccharomyces cerevisiae) for in-plant process validation studies. Wheat flour was inoculated (∼6 log CFU/g) with three Salmonella serovars (Typhimurium, Newport, or Senftenberg 775W) or with E. faecium.

Prevalence of Enterohemorrhagic Escherichia coli O26, O45, O103, O111, O121, O145, and O157 on Hides and Preintervention Carcass Surfaces of Feedlot Cattle at Harvest.

Cattle hides are a main source of enterohemorrhagic Escherichia coli (EHEC) contamination of beef carcasses. The objectives of this study were to (1) determine the prevalence of "top 6" non-O157 plus O157:H7 EHEC (EHEC-7) on feedlot cattle hides and their matched preintervention carcasses; (2) assess the agreement among detection methods for these matrices; and (3) conduct a molecular risk assessment of EHEC-7 isolates. Samples from 576 feedlot cattle were obtained at a commercial harvest facility and tested for EHEC-7 by a culture-based method and the polymerase chain reaction/mass spectrometry-based NeoSEEK(™) STEC Detection and Identification test (NS).

Plant extract enhances the viability of Lactobacillus delbrueckii subsp. bulgaricus and Lactobacillus acidophilus in probiotic nonfat yogurt.

A commercial plant extract (prepared from olive, garlic, onion and citrus extracts with sodium acetate (SA) as a carrier) was evaluated to extend the viability of yogurt starter and probiotic bacteria as a means to enhance the shelf life of live and active culture, probiotic nonfat yogurt. Yogurts prepared from three different formulas (0.5* plant extract, 0.

Thermal inactivation of Escherichia coli O157:H7 in blade-tenderized beef steaks cooked on a commercial open-flame gas grill.

Beef subprimals were inoculated on the lean side with ca. 4.0 log CFU/g of a cocktail of rifampin-resistant (Rif(r)) Escherichia coli O157:H7 strains and then passed once through a mechanical blade tenderizer with the lean side facing upward.

Detection of Escherichia coli O157:H7 in cattle feces using a polymerase chain reaction-based fluorogenic 5' nuclease (TaqMan) detection assay after secondary enrichment.

Currently, methods for recovering and identifying Escherichia coli O157:H7 from cattle feces are inconsistent and hindered by their inability to specifically and rapidly detect small numbers of organisms from this complex and highly variable matrix. A standard approach for isolating and characterizing E. coli O157:H7 from cattle feces was compared with a polymerase chain reaction (PCR)-based 5' nuclease assay specific for E.