Evaluation of a Postbiotic on Salmonella enterica Prevalence, Serotype Diversity, and Antimicrobial Resistance in the Subiliac Lymph Nodes of Cull Dairy Cattle.

This study aimed to determine whether the farm-level use of a Saccharomyces cerevisiae-based postbiotic was associated with Salmonella prevalence and concentration, serotype diversity, and antimicrobial resistance in the subiliac lymph nodes (LN) of cull dairy cows. In collaboration with two commercial processing plants in the Southwestern (SW) and Northeastern (NE) regions of the U.S.

Safety assessment of Mpp75Aa1.1, a new ETX_MTX2 protein from Brevibacillus laterosporus that controls western corn rootworm.

The recently discovered insecticidal protein Mpp75Aa1.1 from Brevibacillus laterosporus is a member of the ETX_MTX family of beta-pore forming proteins (β-PFPs) expressed in genetically modified (GM) maize to control western corn rootworm (WCR; Diabrotica virgifera virgifera LeConte). In this manuscript, bioinformatic analysis establishes that although Mpp75Aa1.

Food and feed safety of the Bacillus thuringiensis derived protein Vpb4Da2, a novel protein for control of western corn rootworm.

Western corn rootworm (WCR), Diabrotica virgifera virgifera, LeConte, is an insect pest that poses a significant threat to the productivity of modern agriculture, causing significant economic and crop losses. The development of genetically modified (GM) crops expressing one or more proteins that confer tolerance to specific insect pests, such as WCR, was a historic breakthrough in agricultural biotechnology and continues to serve as an invaluable tool in pest management. Despite this, evolving resistance to existing insect control proteins expressed in current generation GM crops requires continued identification of new proteins with distinct modes of action while retaining targeted insecticidal efficacy.

Kinome Analysis of Cattle Peripheral Lymph Nodes to Elucidate Differential Response to spp.

spp., contained within the peripheral lymph nodes (PLNs) of cattle, represents a significant source of contamination of ground beef. Herein is the first report where species-specific kinome peptide arrays designed for bovine biology were used to further the understanding of spp.

Evaluation of a Preharvest Bacteriophage Therapy for Control of Salmonella within Bovine Peripheral Lymph Nodes.

Abstract: A series of proof-of-concept studies were developed to determine whether a commercial bacteriophage cocktail could be utilized for the mitigation of Salmonella in bovine peripheral lymph nodes (LNs). The first objective sought to determine whether exogenous phage could be isolated from the LNs following administration. If isolation were successful, the second objective was to determine whether the phage in the LNs could effectively reduce Salmonella.

Some aspects of the acute phase immune response to a lipopolysaccharide (LPS) challenge are mitigated by supplementation with a fermentation product in weaned beef calves.

This study was conducted to determine if feeding a fermentation product (SCFP) to calves would alter the acute phase response to a lipopolysaccharide (LPS) challenge. Crossbred steer calves [ = 32; 274 ± 1.9 kg body weight (BW)] were randomly allotted to two treatment diets for 21 d: 1) control, fed RAMP (Cargill, Dalhart, TX) and 2) SCFP, fed the control ration supplemented with NaturSafe at 12 g/hd/d mixed into the TMR (NaturSafe, Diamond V, Cedar Rapids, IA).

Evaluation of two commercially-available vaccines on in the peripheral lymph nodes of experimentally-infected cattle.

Background: is a common inhabitant of the ruminant gastrointestinal tract, where it often resides asymptomatically and may be shed into the feces. More recently it was discovered that may be contained within the peripheral, non-mesenteric lymph nodes, where it is impervious to in-plant pathogen control interventions and may serve as a source of -contamination of ground beef. Over the past 10 years considerable research effort has been expended at understanding how this pathogen gets to these lymph nodes, the duration of infection, and, most importantly, screening and developing potential intervention strategies that may be employed on farm prior to the animal being presented for slaughter.

Presence of small resistant peptides from new in vitro digestion assays detected by liquid chromatography tandem mass spectrometry: An implication of allergenicity prediction of novel proteins?

The susceptibility of newly expressed proteins to digestion by gastrointestinal proteases (e.g., pepsin) has long been regarded as one of the important endpoints in the weight-of-evidence (WOE) approach to assess the allergenic risk of genetically modified (GM) crops.

Evaluation of the Efficacy of Three Direct Fed Microbial Cocktails To Reduce Fecal Shedding of O157:H7 in Naturally Colonized Cattle and Fecal Shedding and Peripheral Lymph Node Carriage of in Experimentally Infected Cattle.

Two experiments were conducted to evaluate the feeding of direct fed microbials (DFMs) on fecal shedding of O157:H7 in naturally infected cattle (experiment I) and on in the feces and peripheral lymph nodes (PLNs) of experimentally infected cattle (experiment II). Thirty cattle, 10 per treatment, were used in each experiment. Treatments in experiment I consisted of a control (lactose carrier only); DFM1, a 1:1 ratio of and ; and DFM2, a 1:1 ratio of and .

Effect of common processing of soybeans on the enzymatic activity and detectability of the protein, Dicamba Mono-Oxygenase (DMO), introduced into dicamba-tolerant MON 87708.

Assessing the safety of genetically engineered crops includes evaluating the risk (hazard and exposure) of consuming their newly expressed proteins. The dicamba monooxygenase (DMO) protein, introduced into soybeans to confer tolerance (DT) to dicamba herbicide, was previously characterized and identified to pose no food or feed safety hazards. Most agricultural commodities (e.

Safety of the Bacillus thuringiensis-derived Cry1A.105 protein: Evidence that domain exchange preserves mode of action and safety.

The lepidopteran-active Cry1A.105 protein is a chimeric three-domain insecticidal toxin with distinct structural domains derived from the naturally occurring Cry1Ab, Cry1Ac and Cry1F proteins from the soil bacterium Bacillus thuringiensis (Bt). The X-ray crystal structure of the Cry1A.

Protease resistance of food proteins: a mixed picture for predicting allergenicity but a useful tool for assessing exposure.

Background: Susceptibility to pepsin digestion of candidate transgene products is regarded an important parameter in the weight-of-evidence approach for allergenicity risk assessment of genetically modified crops. It has been argued that protocols used for this assessment should better reflect physiological conditions encountered in representative food consumption scenarios.

Aim: To evaluate whether inclusion of more physiological conditions, such as sub-optimal and lower pepsin concentrations, in combination with pancreatin digestion, improved the performance of digestibility protocols used in characterization of protein stability.

Effect of waste milk pasteurization on fecal shedding of Salmonella in preweaned calves.

The objective of the current research was to determine if pasteurization of nonsaleable waste milk influences fecal Salmonella concentrations and prevalence, or antimicrobial susceptibility and serotype of the cultured isolates. Holstein dairy calves (n = 211) were housed on a single commercial dairy in the southwestern United States and randomly allotted to be fed either pasteurized (PWM; n = 128 calves) or nonpasteurized waste milk (NPWM; n = 83 calves). Fecal samples were collected via rectal palpation or from freshly voided, undisturbed fecal pats, weekly during the first 4 wk of the animal's life and then again at weaning.

Neutral barcoding of genomes reveals the dynamics of Salmonella colonization in cattle and their peripheral lymph nodes.

Feedlot cattle often contain Salmonella. The number of bacteria that initiate colonization of different cattle organs and the bacterial migration within these large animals are poorly understood. To investigate these questions, we constructed wild-type isogenic tagged strains (WITS) of Salmonella by inserting 21-base barcodes flanked by Illumina sequencing primers into a neutral genome location.

Silicone Hydrogel and Rigid Gas-Permeable Scleral Lens Tear Exchange.

Objectives: To quantify tear elimination rate (ER) underneath silicone hydrogel (Si-Hy) and scleral gas permeable (GP) contact lenses (CLs).

Methods: Subjects successfully using either well-fitting soft Si-Hy CLs or scleral GP CLs were recruited. Most scleral GP CL wearers had irregular corneas (e.

in Peripheral Lymph Nodes of Healthy Cattle at Slaughter.

To more fully characterize the burden of in bovine peripheral lymph nodes (PLN), PLN ( = 5,450) were collected from healthy cattle at slaughter in 12 commercial abattoirs that slaughtered feedlot-fattened (FF) cattle exclusively ( = 7), cattle removed (or culled) from breeding herds ( = 3), or both FF and cull cattle ( = 2). Qualitative and quantitative methods were used to estimate prevalence and concentration of in PLN. Isolates were subjected to a variety of phenotypic, serological, and molecular assays.

Improving insect control protein activity for GM crops: A case study demonstrating that increased target insect potency can be achieved without impacting mammalian safety.

Many insect-protected crops express insecticidal crystal (Cry) proteins derived from the soil bacterium Bacillus thuringiensis (Bt), including both naturally-occurring Cry proteins and chimeric Cry proteins created through biotechnology. The Cry51Aa2 protein is a naturally-occurring Cry protein that was modified to increase its potency and expand its insect activity spectrum through amino acid sequence changes. The improved Cry51Aa2 variant, Cry51Aa2.

Analyzing pepsin degradation assay conditions used for allergenicity assessments to ensure that pepsin susceptible and pepsin resistant dietary proteins are distinguishable.

The susceptibility of a dietary protein to proteolytic degradation by digestive enzymes, such as gastric pepsin, provides information on the likelihood of systemic exposure to a structurally intact and biologically active macromolecule, thus informing on the safety of proteins for human and animal consumption. Therefore, the purpose of standardized in vitro degradation studies that are performed during protein safety assessments is to distinguish whether proteins of interest are susceptible or resistant to pepsin degradation via a study design that enables study-to-study comparison. Attempting to assess pepsin degradation under a wide-range of possible physiological conditions poses a problem because of the lack of robust and consistent data collected under a large-range of sub-optimal conditions, which undermines the needs to harmonize in vitro degradation conditions.

Assessment of Natural Variability of Maize Lipid Transfer Protein Using a Validated Sandwich ELISA.

Lipid transfer protein (LTP) is the main causative agent for rare food allergic reactions to maize. This paper describes a new, validated ELISA that accurately measures maize LTP concentrations from 0.2 to 6.

Modeling Corneal Oxygen with Scleral Gas Permeable Lens Wear.

Purpose: The main goal of this current work is to use an updated calculation paradigm, and updated boundary conditions, to provide theoretical guidelines to assist the clinician whose goal is to improve his or her scleral gas permeable (GP) contact lens wearing patients' anterior corneal oxygen supply.

Methods: Our model uses a variable value of corneal oxygen consumption developed through Monod equations that disallows negative oxygen tensions within the stroma to predict oxygen tension at the anterior corneal surface of scleral GP contact lens wearing eyes, and to describe oxygen tension and flux profiles, for various boundary conditions, through the lens, tears, and cornea. We use several updated tissue and boundary parameters in our model.

Assessing Transmission of Salmonella to Bovine Peripheral Lymph Nodes upon Horn Fly Feeding.

Biting arthropods are implicated in the transdermal transmission of Salmonella to bovine peripheral lymph nodes, and such contamination can contribute to increased Salmonella prevalence in processed beef. Since horn flies can acquire Salmonella and then excrete the bacteria in their feces, on-animal fly infestations were conducted in this study to assess whether horn flies have a role in this bacterial transmission. Three Salmonella serotypes were used to assess fly acquisition from and excretion onto cattle.

Efficacy of a Salmonella Siderophore Receptor Protein Vaccine on Fecal Shedding and Lymph Node Carriage of Salmonella in Commercial Feedlot Cattle.

The efficacy of a Salmonella vaccine for reducing fecal shedding of Salmonella during the finishing period and lymph node (LN) carriage at harvest was investigated in commercial feedlot cattle. The study was designed as a pen-level randomized complete block with two treatment groups, a Salmonella Newport siderophore receptor and porin proteins-based vaccine (VAC) and a nonvaccinated control (CON). Cattle were randomly allocated into 24 pens within 12 blocks based on the time of allocation.

Salmonella Persistence within the Peripheral Lymph Nodes of Cattle following Experimental Inoculation.

Utilizing a transdermal method of inoculation developed in our laboratory, the duration of infection of Salmonella in the peripheral lymph nodes of steers was examined. Thirty-six Holstein steers (mean body weight of 137 kg) were inoculated with Salmonella Montevideo (day 0) on each lower leg and both sides of the back and abdomen. Calves were euthanized beginning at 6 h and subsequently on each of days 1, 2, 4, 7, 9, 11, 14, and 21 postinoculation (four animals each time).

The sequence, structural, and functional diversity within a protein family and implications for specificity and safety: The case for ETX_MTX2 insecticidal proteins.

The need for sustainable insect pest control is driving the investigation and discovery of insecticidal proteins outside of the typical 3-domain Cry protein family from Bacillus thuringiensis (Bt). Examples include Cry35 and Cry51 that belong to protein families (Toxin_10, ETX_MTX2) sharing a common β-pore forming structure and function with known mammalian toxins such as epsilon toxin (ETX). Although β-pore forming proteins are related to mammalian toxins, there are key differences in sequence and structure that lead to organism specificity that is useful in the weight-of-evidence approach for safety assessment.

Salmonella Prevalence and Antimicrobial Susceptibility Among Dairy Farm Environmental Samples Collected in Texas.

Dairy cattle are a reservoir of several Salmonella serovars that are leading causes of human salmonellosis. The objectives of this study were to estimate the environmental prevalence of Salmonella on dairy farms in Texas and to characterize the antimicrobial susceptibility of the isolates. Eleven dairy farms throughout Texas were sampled from August through October 2013, using a cross-sectional approach.