Pathogenic diversification of the gut commensal via acquisition of a second type III secretion system.

is a Gram-negative bacterium found in various water and land environments and organisms, including insects and mammals. Some strains encode gene homologs of virulence factors found in pathogenic Enterobacterales members, such as serovar Typhimurium and . Whether these genes are pathogenic determinants in is not known.

Sensitivity of dairy calf serotype Cerro isolates to infection-relevant stressors.

serotype Cerro (. Cerro) is an emerging serotype isolated from cattle, but the association of . Cerro with disease is not well understood.

Pathogenic diversification of the gut commensal via acquisition of a second type III secretion system.

is a Gram-negative bacterium found in a wide variety of water and land environments and organisms. It has been isolated as part of the gut microbiome of animals and insects, as well as from stool samples of patients with diarrhea. Specific strains encode gene homologs of virulence factors found in other pathogenic members of the same Enterobacterales order, such as serovar Typhimurium and Whether these genes are also pathogenic determinants in is not known.

MARCKS Inhibition Alters Bovine Neutrophil Responses to Typhimurium.

Neutrophils are innate immune cells that respond quickly to sites of bacterial infection and play an essential role in host defense. Interestingly, some bacterial pathogens benefit from exuberant neutrophil inflammation. is one such pathogen that can utilize the toxic mediators released by neutrophils to colonize the intestine and cause enterocolitis.

Bacterial retrons encode phage-defending tripartite toxin-antitoxin systems.

Retrons are prokaryotic genetic retroelements encoding a reverse transcriptase that produces multi-copy single-stranded DNA (msDNA). Despite decades of research on the biosynthesis of msDNA, the function and physiological roles of retrons have remained unknown. Here we show that Retron-Sen2 of Salmonella enterica serovar Typhimurium encodes an accessory toxin protein, STM14_4640, which we renamed as RcaT.

Comparative Genomics of Atypical Enteropathogenic Escherichia coli from Kittens and Children Identifies Bacterial Factors Associated with Virulence in Kittens.

Typical enteropathogenic (tEPEC) is a leading cause of diarrhea and associated death in children worldwide. Atypical EPEC (aEPEC) lacks the plasmid encoding bundle-forming pili and is considered less virulent, but the molecular mechanism of virulence is poorly understood. We recently identified kittens as a host for aEPEC where intestinal epithelial colonization was associated with diarrheal disease and death.

Disease features of equine coronavirus and enteric salmonellosis are similar in horses.

Background: Equine coronavirus (ECoV) is an emerging pathogen associated with fever and enteric disease in adult horses. Clinical features of ECoV infection have been described, but no study has compared these features to those of Salmonella infections.

Objectives: Compare the clinical features of ECoV infection with enteric salmonellosis and establish a disease signature to increase clinical suspicion of ECoV infection in adult horses.

Evaluation of vaporized hydrogen peroxide sterilization on the in vitro efficacy of meropenem-impregnated polymethyl methacrylate beads.

OBJECTIVE To evaluate the effects of vaporized hydrogen peroxide (VHP) sterilization on the in vitro antimicrobial efficacy of meropenem-impregnated polymethyl methacrylate (M-PMMA) beads. SAMPLE 6-mm-diameter polymethyl methacrylate beads that were or were not impregnated with meropenem. PROCEDURES Meropenem-free polymethyl methacrylate and M-PMMA beads were sterilized by use of an autoclave or VHP or remained unsterilized.

The Salmonella type-3 secretion system-1 and flagellar motility influence the neutrophil respiratory burst.

Neutrophils are innate immune response cells designed to kill invading microorganisms. One of the mechanisms neutrophils use to kill bacteria is generation of damaging reactive oxygen species (ROS) via the respiratory burst. However, during enteric salmonellosis, neutrophil-derived ROS actually facilitates Salmonella expansion and survival in the gut.

Salmonella Activation of STAT3 Signaling by SarA Effector Promotes Intracellular Replication and Production of IL-10.

Salmonella enterica is an important foodborne pathogen that uses secreted effector proteins to manipulate host pathways to facilitate survival and dissemination. Different S. enterica serovars cause disease syndromes ranging from gastroenteritis to typhoid fever and vary in their effector repertoire.

A Regulator Modulates Intestinal Colonization and Use of Phosphonoacetic Acid.

Many microorganisms produce phosphonates, molecules characterized by stable carbon-phosphorus bonds that store phosphorus or act as antimicrobials. The role of phosphonates in the marine biosphere is well characterized but the role of these molecules in the intestine is poorly understood. uses its virulence factors to influence the host immune response to compete with the host and normal microflora for nutrients.

Novel Two-Step Hierarchical Screening of Mutant Pools Reveals Mutants under Selection in Chicks.

Contaminated chicken/egg products are major sources of human salmonellosis, yet the strategies used by Salmonella to colonize chickens are poorly understood. We applied a novel two-step hierarchical procedure to identify new genes important for colonization and persistence of Salmonella enterica serotype Typhimurium in chickens. A library of 182 S.

Multicopy Single-Stranded DNA Directs Intestinal Colonization of Enteric Pathogens.

Multicopy single-stranded DNAs (msDNAs) are hybrid RNA-DNA molecules encoded on retroelements called retrons and produced by the action of retron reverse transcriptases. Retrons are widespread in bacteria but the natural function of msDNA has remained elusive despite 30 years of study. The major roadblock to elucidation of the function of these unique molecules has been the lack of any identifiable phenotypes for mutants unable to make msDNA.

Systemic and anti-nociceptive effects of prolonged lidocaine, ketamine, and butorphanol infusions alone and in combination in healthy horses.

Background: Prolonged drug infusions are used to treat horses with severe signs of pain, but can be associated with altered gastrointestinal transit. The purpose of this study was to determine the effects of prolonged constant rate infusions (CRI) of lidocaine (L), butorphanol (B), and ketamine (K) alone and in combination on gastrointestinal transit, behavior, and thermal nociceptive threshold in healthy horses.

Methods: Eight healthy adult horses were used in a randomized, cross-over, blinded, prospective experimental trial.

Novel determinants of intestinal colonization of Salmonella enterica serotype typhimurium identified in bovine enteric infection.

Cattle are naturally infected with Salmonella enterica serotype Typhimurium and exhibit pathological features of enteric salmonellosis that closely resemble those in humans. Cattle are the most relevant model of gastrointestinal disease resulting from nontyphoidal Salmonella infection in an animal with an intact microbiota. We utilized this model to screen a library of targeted single-gene deletion mutants to identify novel genes of Salmonella Typhimurium required for survival during enteric infection.

Effect of detomidine on visceral and somatic nociception and duodenal motility in conscious adult horses.

Objective: To evaluate the effects of detomidine on visceral and somatic nociception, heart and respiratory rates, sedation, and duodenal motility and to correlate these effects with serum detomidine concentrations.

Study Design: Nonrandomized, experimental trial.

Animals: Five adult horses, each with a permanent gastric cannula weighing 534 +/- 46 kg.

Effect of acepromazine, butorphanol, or N-butylscopolammonium bromide on visceral and somatic nociception and duodenal motility in conscious horses.

Objective: To evaluate effects of butorphanol, acepromazine, and N-butylscopolammonium bromide (NBB) on visceral and somatic nociception and duodenal motility in conscious, healthy horses.

Animals: 6 adult horses.

Procedures: Visceral nociception was evaluated by use of colorectal distention (CRD) and duodenal distention (DD) threshold.