Immunogenicity of live phoP gene deletion strain of Riemerella anatipestifer serotype 1.

Duck infectious serositis is an acute and infectious disease caused by Riemerella anatipestifer (R. anatipestifer) that leads to perihepatitis, pericarditis, meningitis, and airbag inflammation in ducks, which causes serious economic losses to the global duck industry. The phoP/phoR is a novel 2-component signal transduction system first reported in gram-negative bacteria, of which phoP acts as a global regulator and virulence factor. In this study, the phoP gene from the R. anatipestifer YM strain was knocked out using homologous recombination technology and replaced with the spectinomycin resistance gene (Spec). The virulence of the R. anatipestifer YMΔphoP strain was reduced by approximately 47,000 times compared to that of the wild-type R. anatipestifer YM strain. Ducks were immunized with live R. anatipestifer YMΔphoP strain by subcutaneous inoculation at a dose of 106 to 107 CFU (0.2 mL per duck) and challenged with the wild-type R. anatipestifer YM strain 14 days later. The protection rate in the immunized group was 100%. The growth characteristics of ducks in the immunized and negative control groups were normal, and the research demonstrated R. anatipestifer YMΔphoP strain have suitable immunogenicity and protective effects. Thus, the study findings suggest that the novel R. anatipestifer YMΔphoP strain may provide a candidate for the development of a gene deletion activated vaccine against duck infectious serositis.

Enhanced cross-lineage protection induced by recombinant H9N2 avian influenza virus inactivated vaccine.

BACKGROUND: Antigenic drift of H9N2 low pathogenic avian influenza viruses (AIV) may result in vaccination failure in the poultry industry and thus a cross-protective vaccine against H9N2 AIV is highly desirable. METHODS: A series of H9N2 recombinant viruses with the internal genes of A/Puerto Rico/8/34 (H1N1, PR8) were generated, based on the compatibility between HA and NA, the effect of HA deglycosylation, and protective antigenic epitopes in HA. After evaluation of their biological and immunological characteristics, three recombinant AIVs with the internal genes of the Y280-like strain SN were selected for protective efficacy studies. RESULTS: The recombinant viruses rHASNNA3, rHASN-△200, rHASN-△287, and rHASN-R92G-E93K displayed good cross reactivity and induced higher neutralization antibody titers against both SN and the F98-like strain YZ4. Furthermore, those recombinant viruses had a higher EID50 in chicken embryos after the replacement of internal-gene backbone from PR8 to SN. The rSNHA-△200 induced better protection in immunized chickens against challenge of homologous and heterologous H9N2 avian influenza viruses when compared with the wild type strain. CONCLUSION: The recombinant virus rSNHA-△200 can be used as a potential broad-spectrum vaccine against H9N2 avian influenza.

Development of a Colloidal Gold-Based Immunochromatographic Strip for Rapid Detection of H7N9 Influenza Viruses.

Both high- and low-pathogenic H7N9 influenza A virus (IAV) infections have been found in human and poultry in China, and most human cases are related to contact with infected poultry. It is necessary to develop a rapid and simple method to detect H7N9 IAV in poultry. In this study, 13 monoclonal antibodies (McAbs) against the H7N9 IAV hemagglutinin were developed, and three critical amino acid epitopes (198, 227, 235) were identified based on the reactivity of these variant and wild-type strains with the McAbs. We developed an immunochromatographic assay for H7N9 AIVs using two McAbs recognizing the epitope position 227 and 235. The assay had good specificity, stability, and sensitivity, with a detection limit of swab and tissue samples of 2.5 log10EID50/0.1 mL, which is suitable for the analysis of clinical samples. This assay provides an effective method for the rapid detection of H7N9 AIVs in poultry.

PHACTR1 and SLC22A3 gene polymorphisms are associated with reduced coronary artery disease risk in the male Chinese Han population.

Previous studies showed that PHACTR1 and SLC22A3 are involved in coronary vascular development and are key determinants of cardiovascular disease risk. We conducted a case-control study to examine the effect of SLC22A3 and PHACTR1 single nucleotide polymorphisms (SNPs) on CAD risk among 376 male CAD patients and 388 male healthy controls from China. Eleven SLC22A3 and PHACTR1 SNPs were selected and genotyped using Sequenom Mass-ARRAY technology. Odds ratios (OR) and 95% confidence intervals (CIs) were calculated using unconditional logistic regression adjusting for age. The rs9381439 minor allele "A" (OR = 0.72; 95% CI = 0.54-0.96; p = 0.024) in an allelic model was associated with reduced CAD risk, as were the rs2048327 "C/C" (OR = 0.60; 95% CI: 0.37-0.97; p = 0.036) and rs1810126 "T/T" (OR = 0.58; 95% CI: 0.36-0.93; p = 0.024) genotypes. Likewise, the rs9349379 "A/G" genotype in a dominant model (p = 0.041), the rs1810126 "T/C" genotype in additive (p = 0.041) and recessive (p = 0.012) models, and the rs2048327 "C/T" genotype in a recessive model were associated with decreased CAD risk (p = 0.016). These results suggest several PHACTR1 and SLC22A3 polymorphisms are associated with decreased CAD risk in the male Chinese Han population.

Association of IL-1A and IL-1B polymorphisms with ankylosing spondylitis among the Chinese Han population: a case-control study.

Ankylosing spondylitis (AS) is a complex and chronic inflammatory disease with a high heritage. Previous study has shown that IL-1A and IL-1B involved in inflammatory reaction. But little is known about single nucleotide polymorphisms (SNPs) of IL-1A and IL-1B associated with AS. We conducted a case-control study among 267 AS cases and 297 healthy controls from China. In the genetic model analysis, we found the "T" genotype of rs3783550 was associated with decreased AS risk in the dominant model (p = 0.044) and log-additive model (p = 0.023); the "C" genotype of rs3783546 was significantly associated with decreased AS risk based in the dominant model (p = 0.044) and log-additive model (p = 0.023). Additionally, the minor allele "A" of rs2853550 may also reduce the risk of AS in dominant (p = 0.025) and log-additive model (p = 0.024). Our results suggested that the polymorphisms of IL-1A and IL-1B are associated with the AS susceptibility in the Chinese Han population. Further studies are needed to characterize the functional sequences that cause AS.