7 research outputs found
Exploring the predictive power of jejunal microbiome composition in clinical and subclinical necrotic enteritis caused by Clostridium perfringens: insights from a broiler chicken model
No full textBackground: Necrotic enteritis (NE) is a severe intestinal infection that affects both humans and poultry. It is caused by the bacterium Clostridium perfringens (CP), but the precise mechanisms underlying the disease pathogenesis remain elusive. This study aims to develop an NE broiler chicken model, explore the impact of the microbiome on NE pathogenesis, and study the virulence of CP isolates with different toxin gene combinations.
Methods: This study established an animal disease model for NE in broiler chickens. The methodology encompassed inducing abrupt protein changes and immunosuppression in the first experiment, and in the second, challenging chickens with CP isolates containing various toxin genes. NE was evaluated through gross and histopathological scoring of the jejunum. Subsequently, jejunal contents were collected from these birds for microbiome analysis via 16S rRNA amplicon sequencing, followed by sequence analysis to investigate microbial diversity and abundance, employing different bioinformatic approaches.
Results: Our findings reveal that CP infection, combined with an abrupt increase in dietary protein concentration and/or infection with the immunosuppressive variant infectious bursal disease virus (vIBDV), predisposed birds to NE development. We observed a significant decrease (p < 0.0001) in the abundance of Lactobacillus and Romboutsia genera in the jejunum, accompanied by a notable increase (p < 0.0001) in Clostridium and Escherichia. Jejunal microbial dysbiosis and severe NE lesions were particularly evident in birds infected with CP isolates containing cpa, netB, tpeL, and cpb2 toxin genes, compared to CP isolates with other toxin gene combinations. Notably, birds that did not develop clinical or subclinical NE following CP infection exhibited a significantly higher (p < 0.0001) level of Romboutsia. These findings shed light on the complex interplay between CP infection, the gut microbiome, and NE pathogenesis in broiler chickens.
Conclusion: Our study establishes that dysbiosis within the jejunal microbiome serves as a reliable biomarker for detecting subclinical and clinical NE in broiler chicken models. Additionally, we identify the potential of the genera Romboutsia and Lactobacillus as promising candidates for probiotic development, offering effective alternatives to antibiotics in NE prevention and control.Chicken Farmers of Saskatchewan and Poultry ScienceCluster II
Oligodeoxynucleotides containing CpG motifs upregulate bactericidal activities of heterophils and enhance immunoprotection of neonatal broiler chickens against Salmonella Typhimurium septicemia
No full textIn the past, we demonstrated that oligodeoxynucleotides containing CpG motifs (CpG-ODN) mimicking bacterial DNA, stimulate the innate immune system of neonatal broiler chickens and protect them against Escherichia coli and Salmonella Typhimurium (S. Typhimurium) septicemia. The first line of innate immune defense mechanism is formed by heterophils and plays a critical protective role against bacterial septicemia in avian species. Therefore, the objectives of this study were 1) to explore the kinetics of CpG-ODN mediated antibacterial mechanisms of heterophils following single or twice administration of CpG-ODN in neonatal broiler chickens and 2) to investigate the kinetics of the immunoprotective efficacy of single versus twice administration of CpG-ODN against S. Typhimurium septicemia. In this study, we successfully developed and optimized flow cytometry-based assays to measure phagocytosis, oxidative burst, and degranulation activity of heterophils. Birds that received CpG-ODN had significantly increased (p < 0.05) phagocytosis, oxidative burst, and degranulation activity of heterophils as early as 24 h following CpG-ODN administration. Twice administration of CpG-ODN significantly increased the phagocytosis activity of heterophils. In addition, our newly developed CD107a based flow cytometry assay demonstrated a significantly higher degranulation activity of heterophils following twice than single administration of CpG-ODN. However, the oxidative burst activity of heterophils was not significantly different between birds that received CpG-ODN only once or twice. Furthermore, delivery of CpG-ODN twice increased immunoprotection against S. Typhimurium septicemia compared to once but the difference was not statistically significant. In conclusion, we demonstrated enhanced bactericidal activity of heterophils after administration of CpG-ODN to neonatal broiler chickens. Further investigations will be required to identify other activated innate immune cells and the specific molecular pathways associated with the CpG-ODN mediated activation of heterophils.Chicken Farmers of SaskatchewanNatural Sciences and Engineering Research Council of CanadaDiscovery programResults Driven Agriculture Research progra
Induction of trained immunity in broiler chickens following delivery of oligodeoxynucleotide containing CpG motifs to protect against Escherichia coli septicemia
No full textOligodeoxynucleotides containing CpG motifs (CpG‑ODN) can promote antimicrobial immunity in chickens by enriching immune compartments and activating immune cells. Innate memory, or trained immunity, has been demonstrated in humans and mice, featuring the absence of specificity to the initial stimulus and subsequently cross‑protection against pathogens. We hypothesize that CpG‑ODN can induce trained immunity in chickens. We delivered single or multiple administrations of CpG‑ODN to birds and mitochondrial oxidative phosphorylation (OXPHOS) and glycolysis of peripheral blood mononuclear cells were quantified using Seahorse XFp. Next, chickens were administered with CpG‑ODN twice at 1 and 4 day of age and challenged with Escherichia coli at 27 days of age. The CpG‑ODN administered groups had significantly higher mitochondrial OXPHOS until 21 days of age while cellular glycolysis gradually declined by 14 days of age. The group administered with CpG‑ODN twice at 1 and 4 days of age had significantly higher survival, lower clinical score and bacterial load following challenge with E. coli at 27 d of age. This study demonstrated the induction of trained immunity in broiler chickens following administration of CpG‑ODN twice during the first 4 days of age to protect birds against E. coli septicemia at 27 days of age.Chicken Farmers of SaskatchewanNatural Sciences and Engineering Research Council of Canada (NSERC) Discovery programNSERC AllianceCanadian Poultry Research CouncilResults Driven Agriculture Research Program (RDAR
Development of a multivalent adjuvanted inactivated vaccine against variant arthrotropic avian reoviruses
No full textVariant avian reoviruses (ARVs) are economically important emerging pathogens of poultry, which mainly affect young broiler chickens and cause significant production losses. Currently, there are no effective commercial vaccines available for control and prevention of emerging variant ARVs. In this study, monovalent inactivated adjuvated (20% Emulsigen D) broiler breeder vaccines containing antigens from ARV genotype cluster (C) group -2, -4, -5, or -6, and a multivalent vaccine containing antigens from all the four indicated genotypic cluster groups were developed and evaluated for their efficacy in protecting broiler progenies against homologous or heterologous ARV challenge. The use of monovalent or multivalent inactivated vaccines in a prime-boost immunization strategy induced the production of ARV specific antibodies in broiler breeders. The maternal antibodies were effectively transferred to broiler progenies. Broiler progenies obtained from immunized breeders demonstrated milder clinical symptoms and reduced gross and histopathological lesions after homologous ARV challenge. More severe gross and histological lesions were observed in challenged progenies from unvaccinated broiler breeders. However, cross protection was not observed when either of the monovalent-vaccine groups were challenged with a heterologous virus. In addition, the progenies from the unvaccinated ARV challenged control or heterologous ARV challenged vaccinated groups had significantly reduced body weight gain (p < 0.01) than the unchallenged-control, challenged-multivalent, or homologous ARV-challenged monovalent vaccine groups. However, homologous ARV challenged progenies in the multivalent or monovalent vaccine groups had similar body weight gain as the control unchallenged group with significantly reduced viral load (p < 0.01) in the gastrocnemius tendon tissue. This study indicates that broad-spectrum protection of broiler progenies from variant ARV infections is feasible through the development of multivalent vaccines after proper characterization, selection and incorporation of multiple antigens based on circulating ARV genotypes in targeted regions.Chicken Farmers of SaskatchewanNatural Sciences and Engineering Research Council of CanadaSaskatchewan Agriculture Development Fun
Faculty mentoring in residence halls: an experiential learning process
Get PDF2012 Summer.Includes bibliographical references.As more demands are being placed on faculty inside of the classroom, the debate surrounding the feasibility of faculty having the time and resources to be involved outside the classroom continues. At the same time there is a growing concern that in light of current advancements in technology; oral communication skills, basic to human existence is going by the wayside and the ability to use the fire of conversation can no longer be taken for granted. Campuses also have the challenge of helping students develop their communication, life, and learning skills. In the 21st century, where information is instantly available 24/7 on the internet, critical thinking and life skills need to be stressed and developed (Marques, 2011). White (2011) recommended faculty mentors assist their student mentees in developing problem-solving skills, branching outside their comfort zone, addressing unfamiliar situations, and exploring further self-discovery by guiding versus doing it for them. The research design for this study utilized a large number of questions taken from the National Survey of Student Engagement (NSSE), to solicit feedback on student engagement on an institutional level, along with additional questions supplied by the researcher (referred to as non-NSSE constructs) in order to solicit student and faculty feedback on the impact of faculty mentoring on personal development and experiential learning. This comparative study explored the relationship between faculty mentoring and student engagement (i.e. NSSE constructs), and faculty mentoring and student development and learning (i.e. non-NSSE constructs) in an experiential learning environment (i.e. on-campus residence halls). Students who responded to the open ended question on the survey indicated that the mentor/mentee relationship impacted them in a significant way. Students' introspective comments are reflective and point to an in-depth personal and applied learning experience, where students with mentors found ways to integrate new information from mentors into their own experience. The theoretical population for this study included students living in an on-campus residence hall that offered a faculty mentoring program. Also, the survey sample population involved one public institution in each of the following states: Illinois, California, and Texas. The total number of participants involved in the study was 364. The results of the study suggest that faculty-student interaction outside of the classroom does have an impact on student's personal development and learning. Also, the research revealed that gender had a significant effect on sensitivity to diversity, effective communication, personal growth, personal and social development. Ethnicity had a significant effect on sensitivity to diversity, effective communication, personal growth, personal and social development, support for student success, and reflective learning. In addition, there are a number of practical implications based on the outcome of the survey that can be used by campuses wanting to implement a faculty mentor program or renew and revive an existing one
Genetic association study of NF-κB genes in UK caucasian adult and juvenile onset idiopathic inflammatory myopathy
Get PDFObjective: Treatment-resistant muscle wasting is an increasingly recognized problem in idiopathic inflammatory myopathy (IIM). TNF-α is thought to induce muscle catabolism via activation of nuclear factor-kappa B (NF-κB). Several genes share homology with the NF-κB family of proteins. This study investigated the role of NF-κB-related genes in disease susceptibility in UK Caucasian IIM. Methods: Data from 362 IIM cases [274 adults, 49 (±14.0) years, 72% female; 88 juveniles, 6 (±3.6) years, 73% female) were compared with 307 randomly selected Caucasian controls. DNA was genotyped for 63 single nucleotide polymorphisms (SNPs) from NF-κB-related genes. Data were stratified by IIM subgroup/serotype. Results: A significant allele association was observed in the overall IIM group vs controls for the IKBL-62T allele (rs2071592, odds ratio 1.5, 95% CI 1.21, 1.89, corrected P = 0.0086), which strengthened after stratification by anti-Jo-1 or -PM-Scl antibodies. Genotype analysis revealed an increase for the AT genotype in cases under a dominant model. No other SNP was associated in the overall IIM group. Strong pairwise linkage disequilibrium was noted between IKBL-62T, TNF-308A and HLA-B*08 (D' = 1). Using multivariate regression, the IKBL-62T IIM association was lost after adjustment for TNF-308A or HLA-B*08. Conclusion: An association was noted between IKBL-62T and IIM, with increased risk noted in anti-Jo-1- and -PM-Scl antibody-positive patients. However, the IKBL-62T association is dependent on TNF-308A and HLA-B*08, due to strong shared linkage disequilibrium between these alleles. After adjustment of the 8.1 HLA haplotype, NF-κB genes therefore do not independently confer susceptibility in IIM. © The Author(s) 2011. Published by Oxford University Press on behalf of The British Society for Rheumatology
