Association of Interleukin-10 Cluster Genes and Salmonella Response in the Chicken

Salmonella enteritidis lipopolysaccharide stimulates interleukin 10 (IL10) gene expression in chickens. Four genes in the IL10 cluster [polymeric immunoglobulin receptor (PIGR), interleukin 10 (IL10), map kinase-activated protein kinase 2 (MAPKAPK2), and ligatin (LGTN)] plus dual-specificity tyrosine-(Y)-phosphorylation regulated kinase1A (DYRK1A) were investigated using the F8 generation of 2 related advanced intercross lines (AIL). The AIL were generated by crossing outbred broilers with dams of 2 highly inbred lines (Leghorn and Fayoumi). Intercrossing continued within the 2 dam lines. The F8 chicks (n = 132) were intraesophageally inoculated at 1 d with S. enteritidis. At d 7 or 8, both spleen tissue and cecal contents were cultured to quantify S. enteritidis load. The F8 population was genotyped for one single nucleotide polymorphism (SNP) per gene by using a multiplexed SNaPshot assay. Association of gene SNP with S. enteritidis bacterial burden was analyzed by the GLM. The MAPKAPK2 and IL10 genes were highly (P \u3c 0.001) associated with S. enteritidis burden in spleen tissue and cecal luminal content. Suggestive associations (P \u3c 0.05) of PIGR with spleen tissue and cecal content were found. The results suggest that SNP in MAPKAPK2 and IL10 were strongly associated with Salmonella burden and may be valuable in generating resistant birds by marker-assisted selection

Four Gallinacin genes and Salmonella response in chickens

Salmonella enterica serovar Enteritidis (SE) is a common cause of food poisoning. Through genetic selection of poultry breeding populations by using molecular markers, a greater protection against bacterial infections may be obtained while simultaneously reducing dependence on antibiotic use. Gallinacin genes encode proteins important in innate immunity. Four Gallinacin genes (Gal 6, 11, 12, 13) were selected analyzed by PCR and SNaPshotTM, to detect associations with post-challenge burden of SE. Significant associations (P\u3c0.05) were detected between the cecal content SE bacterial burden and Gal 6, Gal 11, and Gal 13 in the Broiler × Fayoumi AIL-F8; and Gal 12 in the Broiler × Leghorn AIL-F8. These Gallinacin SNPs may be useful in a marker-assisted selection program to improve pre-harvest food safety by genetically enhancing innate immunity to SE

AvBD1 nucleotide polymorphisms, peptide antimicrobial activities and microbial colonisation of the broiler chicken gut

Abstract Background The importance of poultry as a global source of protein underpins the chicken genome and associated SNP data as key tools in selecting and breeding healthy robust birds with improved disease resistance. SNPs affecting host peptides involved in the innate defences tend to be rare, but three non-synonymous SNPs in the avian β-defensin (AvBD1) gene encoding the variant peptides NYH, SSY and NYY were identified that segregated specifically to three lines of commercial broiler chickens Line X (LX), Line Y(LY) and Line Z. The impacts of such amino acid changes on peptide antimicrobial properties were analysed in vitro and described in relation to the caecal microbiota and gut health of LX and LY birds. Results Time-kill and radial immune diffusion assays indicated all three peptides to have antimicrobial properties against gram negative and positive bacteria with a hierarchy of NYH > SSY > NYY. Calcein leakage assays supported AvBD1 NYH as the most potent membrane permeabilising agent although no significant differences in secondary structure were identified to explain this. However, distinct claw regions, identified by 3D modelling and proposed to play a key role in microbial membrane attachment, and permeation, were more distinct in the NYH model. In vivo AvBD1 synthesis was detected in the bird gut epithelia. Analyses of the caecal gut microbiota of young day 4 birds suggested trends in Lactobacilli sp. colonisation at days 4 (9% LX vs × 30% LY) and 28 (20% LX vs 12% LY) respectively, but these were not statistically significant (P > 0.05). Conclusion Amino acid changes altering the killing capacity of the AvBD1 peptide were associated with two different bird lines, but such changes did not impact significantly on caecal gut microbiota

Cell Walls of Saccharomyces cerevisiae Differentially Modulated Innate Immunity and Glucose Metabolism during Late Systemic Inflammation

BACKGROUND: Salmonella causes acute systemic inflammation by using its virulence factors to invade the intestinal epithelium. But, prolonged inflammation may provoke severe body catabolism and immunological diseases. Salmonella has become more life-threatening due to emergence of multiple-antibiotic resistant strains. Mannose-rich oligosaccharides (MOS) from cells walls of Saccharomyces cerevisiae have shown to bind mannose-specific lectin of Gram-negative bacteria including Salmonella, and prevent their adherence to intestinal epithelial cells. However, whether MOS may potentially mitigate systemic inflammation is not investigated yet. Moreover, molecular events underlying innate immune responses and metabolic activities during late inflammation, in presence or absence of MOS, are unknown. METHODS AND PRINCIPAL FINDINGS: Using a Salmonella LPS-induced systemic inflammation chicken model and microarray analysis, we investigated the effects of MOS and virginiamycin (VIRG, a sub-therapeutic antibiotic) on innate immunity and glucose metabolism during late inflammation. Here, we demonstrate that MOS and VIRG modulated innate immunity and metabolic genes differently. Innate immune responses were principally mediated by intestinal IL-3, but not TNF-α, IL-1 or IL-6, whereas glucose mobilization occurred through intestinal gluconeogenesis only. MOS inherently induced IL-3 expression in control hosts. Consequent to LPS challenge, IL-3 induction in VIRG hosts but not differentially expressed in MOS hosts revealed that MOS counteracted LPS's detrimental inflammatory effects. Metabolic pathways are built to elucidate the mechanisms by which VIRG host's higher energy requirements were met: including gene up-regulations for intestinal gluconeogenesis (PEPCK) and liver glycolysis (ENO2), and intriguingly liver fatty acid synthesis through ATP citrate synthase (CS) down-regulation and ATP citrate lyase (ACLY) and malic enzyme (ME) up-regulations. However, MOS host's lower energy demands were sufficiently met through TCA citrate-derived energy, as indicated by CS up-regulation. CONCLUSIONS: MOS terminated inflammation earlier than VIRG and reduced glucose mobilization, thus representing a novel biological strategy to alleviate Salmonella-induced systemic inflammation in human and animal hosts

Comparative Genomic Analysis of Clinical Strains of Campylobacter jejuni from South Africa

BACKGROUND: Campylobacter jejuni is a common cause of acute gastroenteritis and is also associated with the post-infectious neuropathies, Guillain-Barré and Miller Fisher syndromes. In the Cape Town area of South Africa, C. jejuni strains with Penner heat-stable (HS) serotype HS:41 have been observed to be overrepresented among cases of Guillain-Barré syndrome. The present study examined the genetic content of a collection of 32 South African C. jejuni strains with different serotypes, including 13 HS:41 strains, that were recovered from patients with enteritis, Guillain-Barré or Miller Fisher syndromes. The sequence-based typing methods, multilocus sequence typing and DNA microarrays, were employed to potentially identify distinguishing features within the genomes of these C. jejuni strains with various disease outcomes. METHODOLOGY/PRINCIPAL FINDINGS: Comparative genomic analyses demonstrated that the HS:41 South African strains were clearly distinct from the other South African strains. Further DNA microarray analysis demonstrated that the HS:41 strains from South African patients with the Guillain-Barré syndrome or enteritis were highly similar in gene content. Interestingly, the South African HS:41 strains were distinct in gene content when compared to HS:41 strains from other geographical locations due to the presence of genomic islands, referred to as Campylobacter jejuni integrated elements (CJIEs). Only the integrated element CJIE1, a Campylobacter Mu-like prophage, was present in the South African HS:41 strains whereas this element was absent in two closely-related HS:41 strains from Mexico. A more distantly-related HS:41 strain from Canada possessed both integrated elements CJIE1 and CJIE2. CONCLUSION/SIGNIFICANCE: These findings demonstrate that CJIEs may contribute to the differentiation of closely-related C. jejuni strains. In addition, the presence of bacteriophage-related genes in CJIE1 may contribute to the genomic diversity of C. jejuni strains. This comparative genomic analysis of C. jejuni provides fundamental information that potentially could lead to improved methods for analyzing the epidemiology of disease outbreaks

Four Gallinacin genes and Salmonella response in chickens

Salmonella enterica serovar Enteritidis (SE) is a common cause of food poisoning. Through genetic selection of poultry breeding populations by using molecular markers, a greater protection against bacterial infections may be obtained while simultaneously reducing dependence on antibiotic use. Gallinacin genes encode proteins important in innate immunity. Four Gallinacin genes (Gal 6, 11, 12, 13) were selected analyzed by PCR and SNaPshotTM, to detect associations with post-challenge burden of SE. Significant associations (PGal 6, Gal 11, and Gal 13 in the Broiler × Fayoumi AIL-F8; and Gal 12 in the Broiler × Leghorn AIL-F8. These Gallinacin SNPs may be useful in a marker-assisted selection program to improve pre-harvest food safety by genetically enhancing innate immunity to SE.This proceeding is published as Hasenstein, J. R., and S. J. Lamont. "Four Gallinacin genes and Salmonella response in chickens." Proceedings of the 8th World Congress on Genetics Applied to Livestock Production (2006): 15.04. Posted with permission.</p