Massively parallel sequencing of transposon-flanking regions assigned the genotype and fitness score to 91% of Escherichia coli O157:H7 mutants previously screened in cattle by signature-tagged mutagenesis (STM). The method obviates the limitations of STM and markedly extended the functional annotation of the prototype E. coli O157:H7 genome without further animal use.

Salmonella-infected poultry products are a major source of human Salmonella infection. The prophylactic use of antimicrobials in poultry production was recently banned in the EU, increasing the need for alternative methods to control Salmonella infections in poultry flocks. Genetic selection of chickens more resistant to Salmonella colonization provides an attractive means of sustainably controlling the pathogen in commercial poultry flocks and its subsequent entry into the food chain. Analysis of different inbred chickens has shown that individual lines are consistently either susceptible or resistant to the many serovars of Salmonella that have been tested. In this study, two inbred chicken lines with differential susceptibility to Salmonella colonization (61(R) and N(S)) were used in a backcross experimental design. Unlike previous studies that used a candidate gene approach or low-density genome-wide screens, we have exploited a high-density marker set of 1255 SNPs covering the whole genome to identify quantitative trait loci (QTL). Analysis of log-transformed caecal bacterial levels between the parental lines revealed a significant difference at 1, 2, 3 and 4 days post-infection (P

New effective tools for vaccine strategies are necessary to limit the spread of bluetongue, an insect-transmitted viral disease of domestic and wild ruminants. In the present study, BoHV-4-based vector cloned as a bacterial artificial chromosome (BAC) was engineered to express the bluetongue virus (BTV) immune-dominant glycoprotein VP2 provided of a heterologous signal peptide to its amino terminal and a trans-membrane domain to its carboxyl terminal (IgK-VP2gDtm), to allow the VP2 expression targeting to the cell membrane fraction. Based on adult ?/? interferon receptor knockout (IFNAR(?/?)) mice, a newly generated bluetongue laboratory animal model, a pre-challenge experiment was performed to test BoHV-4 safety on such immune-compromised animal. BoHV-4 infected IFNAR(?/?) mice did not show clinical signs even following the inoculation of BoHV-4 intra-cerebrally, although many areas of the brain got transduced. IFNAR(?/?) mice intraperitoneally inoculated twice with BoHV-4-A-IgK-VP2gDtm at different time points developed serum neutralizing antibodies against BTV and showed a strongly reduced viremia and a longer survival time when challenged with a lethal dose of BTV-8. The data acquired in this pilot study validate BoHV-4-based vector as a safe and effective heterologous antigen carrier/producer for the formulation of enhanced recombinant immunogens for the vaccination against lethal bluetongue.

Patr-AL is an expressed, non-polymorphic MHC class I gene carried by ?50% of chimpanzee MHC haplotypes. Comparing Patr-AL+ and Patr-AL? haplotypes showed Patr-AL defines a unique 125-kb genomic block flanked by blocks containing classical Patr-A and pseudogene Patr-H. Orthologous to Patr-AL are polymorphic orangutan Popy-A and the 5? part of human pseudogene HLA-Y, carried by ?10% of HLA haplotypes. Thus, the AL gene alternatively evolved in these closely related species to become classical, nonclassical, and nonfunctional. Although differing by 30 aa substitutions in the peptide-binding ?1 and ?2 domains, Patr-AL and HLA-A*0201 bind overlapping repertoires of peptides; the overlap being comparable with that between the A*0201 and A*0207 subtypes differing by one substitution. Patr-AL thus has the A02 supertypic peptide-binding specificity. Patr-AL and HLA-A*0201 have similar three-dimensional structures, binding peptides in similar conformation. Although comparable in size and shape, the B and F specificity pockets of Patr-AL and HLA-A*0201 differ in both their constituent residues and contacts with peptide anchors. Uniquely shared by Patr-AL, HLA-A*0201, and other members of the A02 supertype are the absence of serine at position 9 in the B pocket and the presence of tyrosine at position 116 in the F pocket. Distinguishing Patr-AL from HLA-A*02 is an unusually electropositive upper face on the ?2 helix. Stimulating PBMCs from Patr-AL? chimpanzees with B cells expressing Patr-AL produced potent alloreactive CD8 T cells with specificity for Patr-AL and no cross-reactivity toward other MHC class I molecules, including HLA-A*02. In contrast, PBMCs from Patr-AL+ chimpanzees are tolerant of Patr-AL.