Induction of innate immune response following infectious bronchitis corona virus infection in the respiratory tract of chickens

AbstractInfectious bronchitis virus (IBV) replicates in the epithelial cells of trachea and lungs of chicken, however the mechanism of generation of innate immune response against IBV infection in these tissues has not been fully characterized. Our objective was to study innate responses induced early following IBV infection in chickens. Initiation of the transcription of selected innate immune genes such as TLR3, TLR7, MyD88, IL-1β and IFN-β, as well as recruitment of macrophages, were evident following an initial down regulation of some of the observed genes (TLR3, IL-1β, and IFN-γ) in trachea and lung. This initial down-regulation followed by the induction of innate immune response to IBV infection appears to be inadequate for the control of IBV genome accumulation and consequent histopathological changes in these tissues. Potential induction of innate immunity before infection occurs may be necessary to reduce the consequences since vaccine induced immunity is slow to develop

Yersinia pseudotuberculosis, iron and disease in birds : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Veterinary Science, Massey University

An epidemiological study was conducted to determine the relative prevalence of yersiniae in different species of wild bird and in the environment. The prevalence of Y. pseudotuberculosis in wild birds, determined using bacteriological techniques, was low. Yersinia pseudotuberculosis was not isolated from environmental samples. The prevalence of other yersiniae isolated from birds was similar to those isolated from the environment in rural locations but not in urban locations. A concurrent serological survey was carried out on a proportion of the wild birds studied. A high number of serologically positive birds indicated frequent exposure to Y. pseudotuberculosis. Clinical cases of pseudotuberculosis in captive birds occurred in the winter and spring following a period of cold weather. Three outbreaks studied involved passeriforms and were associated with poor management. The sporadic cases studied involved individual columbiforms or psittaciforms with concurrent haemosidcrosis. To allow statistical comparisons of the amount and distribution of stainable iron in histological sections, an image analysis system was developed using an experimental model of haemosiderosis in the chicken. Using this technique for a retrospective study of 180 avian cases, it was found that birds which died from infectious diseases had significantly higher levels of iron in the Kupffer cells than did birds which died from non-infectious diseases. The total amount of hepatic iron was not significantly different between the two groups. An experimental model was developed in the chicken to examine the effect of parenteral iron on the pathogenesis of pseudotuberculosis. Challenged birds pre-treated with iron-dextran had higher serological titres to Yersinia lipopolysaccharide, the organism was more readily isolated from the faeces and there were more intestinal lesions than in challenged chickens pre-treated with dextran or desferrioxamine. However, chickens pre-treated with iron-dextran had fewer bacterial lesions in the liver and spleen. Intracellular survival of Y. pseudotuberculosis and Y. frederiksenii in vitro was enhanced in iron loaded macrophages. It was also determined that Y. pseudotuberculosis was able to acquire iron from normal chicken serum

Yersinia pseudotuberculosis, serogroup 0:1A, infection in two Amazon parrots (Amazona aestiva and Amazona oratrix) with hepatic hemosiderosis

Abstract: Necropsies were conducted on a female blue-fronted Amazon (Amazona aestiva) and a female yellow-headed Amazon (Amazona oratrix) that died following depression, ruffled feathers, diarrhea and biliverdin in the urine. Gross and microscopic examinations revealed multifocal necrosis in the liver, spleen, lungs, kidney, intestine and heart caused by acute bacteremia. Yersinia pseudotuberculosis, serogroup O:1a, was isolated by culturing from the visceral lesions in the liver, intestine and spleen. Virulence gene analysis showed the presence of the inv gene and the complete pathogenicity island: IS100, psn, yptE, irp1, irp2 ybtP-ybtQ, ybtX-ybtS, int asnT-Int. Histopathologic findings and chemical analysis also demonstrated hepatic hemosiderosis. As has been demonstrated in other species, we suggest that hemosiderosis may also predispose Amazona spp. to systemic infection with Yersinia pseudotuberculosis following enteric disease

Values for best predictor variables identified by MaxEnt for areas currently above 0.6 probability threshold (60%).

<p>Values for best predictor variables identified by MaxEnt for areas currently above 0.6 probability threshold (60%).</p

Probability distribution for <i>Culicoides sonorensis</i> in southern Alberta and Montana (2010) as estimated by the best performing model (B).

<p>Low probability classes are represented in green (0–40%) and high probability classes in orange (61–80%) and red (81–100%). The intermediate probability class (41–60%) is represented in yellow.</p

Best models developed with MaxEnt predicting <i>Culicoides sonorensis</i> presence in Alberta (Canada) and Montana (US).

<p>Table includes variables included into each best mode (A–E). Variables, percent contribution, permutation importance, corrected AIC, delta (Δ) and Akaike weights (ω) are provided for each best fit model.</p

Correlation matrix showing Pearson correlation coefficients (<i>r</i>) for the 10 predictors that obtained more than 1% contribution and permutation importance in the first preliminary run of MaxEnt.

<p>In <b>bold</b> are reported highly correlated variables (r > 0.5).</p><p>Asterisks indicate highly correlated variables (r > 0.5).</p

Probability distribution maps of <i>Culicoides sonorensis</i> under different projected climate change scenarios (Representative Concentration Pathways, RCP).

<p>A, left panel (2010–2030 scenarios): probability distribution map predicted by MaxEnt for 2010–2030 for each scenario. B, right panel (2030–2050 scenarios): probability distribution map predicted by MaxEnt for 2030–2050 for each RCP scenario. Each RCP is displayed (1) RCP 2.6; (2) RCP 4.5; (3) RCP 8.5.</p

Variables used to characterize habitat for <i>Culicoides sonorensis</i> presence in Alberta (Canada) and Montana (US).

<p>* = North American Regional Reanalysis project (NARR).</p><p>Variables used to characterize habitat for <i>Culicoides sonorensis</i> presence in Alberta (Canada) and Montana (US).</p