Effects of a novel direct-fed microbial on growth performance, carcass characteristics, nutrient digestibility, and ruminal morphology of beef feedlot steers.

The effects of a novel direct-fed microbial (DFM) on feedlot performance, carcass characteristics, digestibility, ruminal morphology, and volatile fatty acid (VFA) profile of finishing steers were evaluated. Single-source Angus-crossbred yearling steers (n = 144; initial body weight (BW) = 371 ± 19 kg) were used in a randomized complete block design. Steers were blocked by initial BW and randomly assigned to treatments (12 pens/treatment; 4 steers/pen).

Reduction of Pathogens in Feces and Lymph Nodes Collected from Beef Cattle Fed (L28), (NP51) and (NP28), Commercially Available Direct-Fed Microbials.

The purpose of the study was to evaluate the prevalence and concentration of foodborne pathogens in the feces and peripheral lymph nodes (PLNs) of beef cattle when supplemented with direct-fed microbials (DFMs) in feedlots. Fecal samples were collected from the pen floors over a 5-month period at three different feedlots in a similar geographical location in Nebraska, where each feed yard represented a treatment group: (i.) control: no supplement, (ii.

A Systematic Approach to Identify and Characterize the Effectiveness and Safety of Novel Probiotic Strains to Control Foodborne Pathogens.

A total of 44 lactic acid bacteria (LAB) strains originally isolated from cattle feces and different food sources were screened for their potential probiotic features. The antimicrobial activity of all isolates was tested by well-diffusion assay and competitive exclusion on broth against Montevideo, O157:H7 and strain N1-002. Thirty-eight LAB strains showed antagonistic effect against at least one of the pathogens tested in this study.

Complete Genome Sequences of Four Salmonella enterica Strains (Including Those of Serotypes Montevideo, Mbandaka, and Lubbock) Isolated from Peripheral Lymph Nodes of Healthy Cattle.

Salmonella enterica serotype Lubbock emerged most likely from a Salmonella enterica serotype Mbandaka ancestor that acquired by recombination the operon from Salmonella enterica serotype Montevideo. Here, we report the complete genome sequence of two Lubbock, one Montevideo, and one Mbandaka strain isolated from bovine lymph nodes.

Draft Genome Sequence of Enterococcus faecium Strain J19, Isolated from Cabbage.

Herein, we report the draft genome sequence of a newly discovered probiotic strain, J19, which was isolated from cabbage. Strain J19 has shown antagonistic effects against the human foodborne pathogen in coculture and in different food matrices.

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.

Draft Genome Sequence of L28 Isolated from Ground Beef.

In this report, we describe the draft genome sequence of a newly discovered probiotic strain, L28. L28 demonstrates antagonistic effects against human foodborne pathogens, including O157:H7, spp., and , in coculture experiments and food matrices.

Carbapenem-Resistant Bacteria Recovered from Faeces of Dairy Cattle in the High Plains Region of the USA.

Objective: A study was conducted to recover carbapenem-resistant bacteria from the faeces of dairy cattle and identify the underlying genetic mechanisms associated with reduced phenotypic susceptibility to carbapenems.

Methods: One hundred and fifty-nine faecal samples from dairy cattle were screened for carbapenem-resistant bacteria. Phenotypic screening was conducted on two media containing ertapenem.

Targeted Amplicon Sequencing for Single-Nucleotide-Polymorphism Genotyping of Attaching and Effacing Escherichia coli O26:H11 Cattle Strains via a High-Throughput Library Preparation Technique.

Enterohemorrhagic Escherichia coli (EHEC) O26:H11, a serotype within Shiga toxin-producing E. coli (STEC) that causes severe human disease, has been considered to have evolved from attaching and effacing E. coli (AEEC) O26:H11 through the acquisition of a Shiga toxin-encoding gene.

Prevalence and distribution of Listeria monocytogenes inlA alleles prone to phase variation and inlA alleles with premature stop codon mutations among human, food, animal, and environmental isolates.

In Listeria monocytogenes, 18 mutations leading to premature stop codons (PMSCs) in the virulence gene inlA have been identified to date. While most of these mutations represent nucleotide substitutions, a frameshift deletion in a 5' seven-adenine homopolymeric tract (HT) in inlA has also been reported. This HT may play a role in phase variation and was first identified among L.

Two Draft Genome Sequences of a New Serovar of Salmonella enterica, Serovar Lubbock.

Salmonella enterica is principally a foodborne pathogen that shows considerable serovar diversity. In this report, we present two draft genome sequences of Salmonella enterica subsp. enterica serovar Lubbock, a novel serovar.

Genetic Diversity and Pathogenic Potential of Attaching and Effacing Escherichia coli O26:H11 Strains Recovered from Bovine Feces in the United States.

Escherichia coli O26 has been identified as the most common non-O157 Shiga toxin-producing E. coli (STEC) serogroup to cause human illnesses in the United States and has been implicated in outbreaks around the world. E.

Geographical and meteorological factors associated with isolation of Listeria species in New York State produce production and natural environments.

Listeria species have been isolated from diverse environments, often at considerable prevalence, and are known to persist in food processing facilities. The presence of Listeria spp. has been suggested to be a marker for Listeria monocytogenes contamination.

Listeria floridensis sp. nov., Listeria aquatica sp. nov., Listeria cornellensis sp. nov., Listeria riparia sp. nov. and Listeria grandensis sp. nov., from agricultural and natural environments.

Sampling of agricultural and natural environments in two US states (Colorado and Florida) yielded 18 Listeria-like isolates that could not be assigned to previously described species using traditional methods. Using whole-genome sequencing and traditional phenotypic methods, we identified five novel species, each with a genome-wide average BLAST nucleotide identity (ANIb) of less than 85% to currently described species. Phylogenetic analysis based on 16S rRNA gene sequences and amino acid sequences of 31 conserved loci showed the existence of four well-supported clades within the genus Listeria; (i) a clade representing Listeria monocytogenes, L.

Substantial within-animal diversity of Salmonella isolates from lymph nodes, feces, and hides of cattle at slaughter.

Lymph nodes (mandibular, mesenteric, mediastinal, and subiliac; n = 68) and fecal (n = 68) and hide (n = 35) samples were collected from beef carcasses harvested in an abattoir in Mexico. Samples were analyzed for Salmonella, and presumptive colonies were subjected to latex agglutination. Of the isolates recovered, a subset of 91 was characterized by serotyping, pulsed-field gel electrophoresis (PFGE), and antimicrobial susceptibility phenotyping.

Genome sequencing identifies Listeria fleischmannii subsp. coloradonensis subsp. nov., isolated from a ranch.

Twenty Listeria-like isolates were obtained from environmental samples collected on a cattle ranch in northern Colorado; all of these isolates were found to share an identical partial sigB sequence, suggesting close relatedness. The isolates were similar to members of the genus Listeria in that they were Gram-stain-positive, short rods, oxidase-negative and catalase-positive; the isolates were similar to Listeria fleischmannii because they were non-motile at 25 °C. 16S rRNA gene sequencing for representative isolates and whole genome sequencing for one isolate was performed.

Landscape and meteorological factors affecting prevalence of three food-borne pathogens in fruit and vegetable farms.

Produce-related outbreaks have been traced back to the preharvest environment. A longitudinal study was conducted on five farms in New York State to characterize the prevalence, persistence, and diversity of food-borne pathogens in fresh produce fields and to determine landscape and meteorological factors that predict their presence. Produce fields were sampled four times per year for 2 years.

Efficacy of chemical interventions against Escherichia coli O157:H7 and multidrug-resistant and antibiotic-susceptible Salmonella on inoculated beef trimmings.

Studies were conducted to compare the decontamination efficacy of six chemical treatments against Escherichia coli O157:H7 and multidrug-resistant and antibiotic-susceptible Salmonella inoculated on beef trimmings. The inocula, comprising four-strain mixtures of rifampin-resistant E. coli O157:H7 and antibiotic-susceptible or multidrug-resistant (MDR and/or MDR-AmpC) Salmonella Newport and Salmonella Typhimurium, were inoculated (3 log CFU/cm(2)) separately onto samples (10 by 5 by 1 cm) derived from beef chuck rolls.

Sensitivity of Shiga toxin-producing Escherichia coli, multidrug-resistant Salmonella, and antibiotic-susceptible Salmonella to lactic acid on inoculated beef trimmings.

Studies were performed to determine whether lactic acid treatments used to reduce Escherichia coli O157:H7 on beef trimmings are also effective in controlling non-O157 Shiga toxin-producing E. coli (nSTEC), and multidrug-resistant and antibiotic-susceptible Salmonella. Beef trimming pieces (10 by 5 by 1 cm) were inoculated (3 log CFU/cm(2)) separately with four-strain mixtures of rifampin-resistant E.

Comparison of decontamination efficacy of antimicrobial treatments for beef trimmings against Escherichia coli O157:H7 and 6 non-O157 Shiga toxin-producing E. coli serogroups.

Unlabelled: The decontamination efficacy of 6 chemical treatments for beef trimmings were evaluated against Escherichia coli O157:H7 and 6 non-O157 Shiga toxin-producing E. coli (nSTEC) serogroups. Rifampicin-resistant 4-strain mixtures of E.

Recombination and positive selection contributed to the evolution of Listeria monocytogenes lineages III and IV, two distinct and well supported uncommon L. monocytogenes lineages.

Listeriamonocytogenes lineages III and IV represent two uncommon lineages of the human and animal pathogen L. monocytogenes, characterized by occurrence of unusual phenotypic and genetic characteristics that differentiate them from the common lineages I and II. To gain further insights into the evolution of lineages III and IV, we amplified and sequenced housekeeping genes (i.

Variation in Listeria monocytogenes dose responses in relation to subtypes encoding a full-length or truncated internalin A.

Internalin A (InlA; encoded by inlA) facilitates the crossing of the intestinal barrier by Listeria monocytogenes. Mutations leading to a premature stop codon (PMSC) in inlA and thus attenuated mammalian virulence have been reported. We recently characterized 502 L.