Tetracycline resistance gene transfer from Escherichia coli donors to Salmonella Heidelberg in chickens is impacted by the genetic context of donors.

Chicken ceca are a rich source of bacteria, including zoonotic pathogens such as Salmonella enterica. The microbiota includes strains/species carrying antimicrobial resistance genes and horizontal transfer of resistance determinants between species may increase the risk to public health and farming systems. Possible sources of these antimicrobial resistance donors - the eggshell carrying bacteria from the hen vertically transmitted to the offspring, or the barn environment where chicks are hatched and raised - has been little explored.

Commercial vaccine provides cross-protection by reducing colonization of Salmonella enterica serovars Infantis and Hadar in turkeys.

Human foodborne outbreaks with antibiotic-resistant Salmonella enterica associated with contaminated poultry products have recently involved serogroup C serovars Infantis and Hadar. The current study evaluated a commercially available Salmonella vaccine for cross-protection against Infantis and Hadar serovars in turkeys. The live, attenuated S.

Genomic and phenotypic comparison of two variants of multidrug-resistant serovar Heidelberg isolated during the 2015-2017 multi-state outbreak in cattle.

subspecies serovar Heidelberg ( Heidelberg) has caused several multistate foodborne outbreaks in the United States, largely associated with the consumption of poultry. However, a 2015-2017 multidrug-resistant (MDR) Heidelberg outbreak was linked to contact with dairy beef calves. Traceback investigations revealed calves infected with outbreak strains of Heidelberg exhibited symptoms of disease frequently followed by death from septicemia.

The immune cell landscape and response of Marek's disease resistant and susceptible chickens infected with Marek's disease virus.

Genetically resistant or susceptible chickens to Marek's disease (MD) have been widely used models to identify the molecular determinants of these phenotypes. However, these prior studies lacked the basic identification and understanding of immune cell types that could be translated toward improved MD control. To gain insights into specific immune cell types and their responses to Marek's disease virus (MDV) infection, we used single-cell RNA sequencing (scRNAseq) on splenic cells from MD resistant and susceptible birds.

Multi-Omics Association Reveals the Effects of Intestinal Microbiome-Host Interactions on Fat Deposition in Broilers.

Growing evidence indicates that gut microbiota factors cannot be viewed as independent in the occurrence of obesity. Because the gut microbiome is highly dimensional and complex, studies on interactions between gut microbiome and host in obesity are still rare. To explore the relationship of gut microbiome-host interactions with obesity, we performed multi-omics associations of gut metagenome, intestinal transcriptome, and host obesity phenotypes in divergently selected obese-lean broiler lines.

Role of the chicken oligoadenylate synthase-like gene during in vitro Newcastle disease virus infection.

The enzyme 2'-5' oligoadenylate synthase (OAS) is one of the key interferon-induced antiviral factors that act through inhibition of viral replication. In chickens, there is a single well-characterized OAS gene, oligoadenylate synthase-like (OASL) that has been shown to be upregulated after infection with various viruses. However, a deeper understanding of how chicken OASL acts against viral infection is still necessary.

Transcriptome Response of Liver and Muscle in Heat-Stressed Laying Hens.

Exposure to high ambient temperature has detrimental effects on poultry welfare and production. Although changes in gene expression due to heat exposure have been well described for broiler chickens, knowledge of the effects of heat on laying hens is still relatively limited. In this study, we profiled the transcriptome for pectoralis major muscle ( = 24) and liver ( = 24), during a 4-week cyclic heating experiment performed on layers in the early phase of egg production.

Genetic resistance to avian pathogenic (APEC): current status and opportunities.

Infections with avian pathogenic (APEC) can be extremely detrimental to poultry health and production. Investigating host genetic variation could identify the biological mechanisms that control resistance to this pathogen and allow selection for improved resistance in experimental and commercial poultry populations. In this review, the current knowledge of how host genetics contributes to APEC resistance and future opportunities that would benefit the understanding or application of genetic resistance are discussed.

Transcriptional response of blood leukocytes from turkeys challenged with Salmonella enterica serovar Typhimurium UK1.

Non-typhoidal Salmonella is one of the most common causes of bacterial foodborne disease and consumption of contaminated poultry products, including turkey, is one source of exposure. Minimizing Salmonella colonization of commercial turkeys could decrease the incidence of Salmonella-associated human foodborne illness. Understanding host responses to these bacteria is critical in developing strategies to minimize colonization and reduce food safety risk.

Induction of Chicken Host Defense Peptides within Disease-Resistant and -Susceptible Lines.

Host defense peptides (HDPs) are multifunctional immune molecules that respond to bacterial and viral pathogens. In the present study, bone marrow-derived cells (BMCs) and chicken embryonic fibroblasts (CEFs) were cultured from a Leghorn line (Ghs6) and Fayoumi line (M15.2), which are inbred chicken lines relatively susceptible and resistant to various diseases, respectively.

Genetic responses of inbred chicken lines illustrate importance of eIF2 family and immune-related genes in resistance to Newcastle disease virus.

Newcastle disease virus (NDV) replication depends on the translation machinery of the host cell; therefore, the eukaryotic translation initiation factor 2 (eIF2) gene family is a likely candidate for control of viral replication. We hypothesized that differential expression of host genes related to translation and innate immune response could contribute to differential resistance to NDV in inbred Fayoumi and Leghorn lines. The expression of twenty-one genes related to the interferon signaling pathway and the eIF2 family was evaluated at two- and six-days post infection (dpi) in the spleen from both lines, either challenged by NDV or nonchallenged.

Avian Pathogenic (APEC) Strain-Dependent Immunomodulation of Respiratory Granulocytes and Mononuclear Phagocytes in -Reporter Transgenic Chickens.

Avian pathogenic (APEC) cause severe respiratory and systemic disease in chickens, commonly termed colibacillosis. Early immune responses after initial infection are highly important for the outcome of the infection. In this study, the early interactions between -expressing APEC strains of serotypes O1:K1:H7 and O2:K1:H5 and phagocytic cells in the lung of -reporter transgenic chickens were investigated.

Genetic lines respond uniquely within the chicken thymic transcriptome to acute heat stress and low dose lipopolysaccharide.

Exposure to high temperatures is known to impair immune functions and disease resistance of poultry. Characterizing changes in the transcriptome can help identify mechanisms by which immune tissues, such as the thymus, respond to heat stress. In this study, 22-day-old chickens from two genetic lines (a relatively resistant Fayoumi line and a more susceptible broiler line) were exposed to acute heat stress (35 °C) and/or immune simulation with lipopolysaccharide (LPS; 100 µg/kg).

Immunomodulatory effects of heat stress and lipopolysaccharide on the bursal transcriptome in two distinct chicken lines.

Background: Exposure to heat stress suppresses poultry immune responses, which can increase susceptibility to infectious diseases and, thereby, intensify the negative effects of heat on poultry welfare and performance. Identifying genes and pathways that are affected by high temperatures, especially heat-induced changes in immune responses, could provide targets to improve disease resistance in chickens. This study utilized RNA-sequencing (RNA-seq) to investigate transcriptome responses in the bursa of Fabricius, a primary immune tissue, after exposure to acute heat stress and/or subcutaneous immune stimulation with lipopolysaccharide (LPS) in a 2 × 2 factorial design: Thermoneutral + Saline, Heat + Saline, Thermoneutral + LPS and Heat + LPS.

Hepatic Transcriptome Responses of Domesticated and Wild Turkey Embryos to Aflatoxin B₁.

The mycotoxin, aflatoxin B₁ (AFB₁) is a hepatotoxic, immunotoxic, and mutagenic contaminant of food and animal feeds. In poultry, AFB₁ can be maternally transferred to embryonated eggs, affecting development, viability and performance after hatch. Domesticated turkeys (Meleagris gallopavo) are especially sensitive to aflatoxicosis, while Eastern wild turkeys (M.

Modulation of the spleen transcriptome in domestic turkey (Meleagris gallopavo) in response to aflatoxin B1 and probiotics.

Poultry are highly susceptible to the immunotoxic effects of the food-borne mycotoxin aflatoxin B1 (AFB1). Exposure impairs cell-mediated and humoral immunity, limits vaccine efficacy, and increases the incidence of costly secondary infections. We investigated the molecular mechanisms of AFB1 immunotoxicity and the ability of a Lactobacillus-based probiotic to protect against aflatoxicosis in the domestic turkey (Meleagris gallopavo).

Response of the hepatic transcriptome to aflatoxin B1 in domestic turkey (Meleagris gallopavo).

Dietary exposure to aflatoxin B1 (AFB1) is detrimental to avian health and leads to major economic losses for the poultry industry. AFB1 is especially hepatotoxic in domestic turkeys (Meleagris gallopavo), since these birds are unable to detoxify AFB1 by glutathione-conjugation. The impacts of AFB1 on the turkey hepatic transcriptome and the potential protection from pretreatment with a Lactobacillus-based probiotic mixture were investigated through RNA-sequencing.

Defining the turkey MHC: identification of expressed class I- and class IIB-like genes independent of the MHC-B.

The MHC of the turkey (Meleagris gallopavo) is divided into two genetically unlinked regions; the MHC-B and MHC-Y. Although previous studies found the turkey MHC-B to be highly similar to that of the chicken, little is known of the gene content and extent of the MHC-Y. This study describes two partially overlapping large-insert BAC clones that genetically and physically map to the turkey MHC chromosome (MGA18) but to a region that assorts independently of MHC-B.