Inclusion body hepatitis (IBH) is one of the major global disease problems, causing significant economic losses to poultry industry of the United States and Canada. The disease is characterized by its sudden onset and high mortalities. Amongst different serotypes of fowl adenoviruses (FAdVs) associated with IBH, serotype 8 of group I FAdV has been isolated from majority of IBH cases. In present studies, we isolated a FAdV from morbid liver of a 17-day-old broiler from a Saskatchewan broiler farm. This newly isolated virus was designated as IBHV(SK). However, based on the sequence analysis of the L1 region of the hexon gene, the IBHV(SK) may be classified as FAdV 8b strain 764. These studies describe for the first time the complete hexon gene sequence of FAdV serotype 8b. Experimental infection of 2-day-old (n = 48) and 2-wk-old (n = 56) chicks caused 83% and 43% mortalities, respectively. Determination of the complete hexon gene sequence of IBHV(SK) with establishment of a disease model in chickens will facilitate the development of type-specific diagnostic reagents and assays for the evaluation of potential experimental vaccines against pathogenic FAdV infections.

The understanding of innate immune modulation by pathogens and immune-modulating agents, including synthetic oligodeoxynucleotides (CpG ODNs), has offered several new approaches to improve prophylactic and therapeutic strategies against infectious diseases in humans and animals. However, in this regard not much work has been done in avian medicine. In the present study, we analyzed the kinetics of interferon (IFN), cytokine, and chemokine mRNA expression in chicken embryonic spleen at 6 hr, 24 hr, 48 hr, and 72 hr after administration of CpG ODN 2007 (B-class) in 18-day-old chicken embryos. Our data showed enhanced expression of IFN-γ; interleukin (IL)-1β, IL-6, and IL-8; and oligoadenyl synthetase A mRNA after CpG ODN administration. In addition, CpG ODN administration to chicken embryos 24 hr before the challenge with infectious bronchitis virus (IBV) was capable of limiting IBV propagation in different embryonic tissues. Based on the kinetics and type of cytokines induced after in ovo administ... Resumen Los oligodeoxinucleótidos CpG (CpG ODNs) activan la respuesta inmune innata que suprime la replicación del virus de la bronquitis infecciosa en embriones de pollos. El conocimiento de la modulación de la inmunidad innata por agentes patógenos o por agentes moduladores incluyendo los oligodeoxinucleótidos sintéticos (CpG ODNs) ha ofrecido varios enfoques nuevos para mejorar las estrategias profilácticas y terapéuticas contra las enfermedades infecciosas en humanos y animales. Sin embargo, en este aspecto no se ha realizado suficiente investigación en medicina aviar. En el presente estudio, se analizó la cinética de la expresión de ARN mensajero de interferón, citoquinas y quimoquinas en bazos embrionarios de pollo a las 6 hrs, 24 hrs, 48 hrs y 72 hrs después de la administración en embriones de 18 días de CpG ODN 2007 (clase B). Nuestros datos mostraron un aumento en la expresión ARNs mensajeros para interferón gama (IFN-γ), interleuquina (IL)-1β, IL-6, IL-8 y para oligoadenilato sintetasa A, despu...

Increasing antibiotic resistance is a matter of grave concern for consumers, public health authorities, farmers, and researchers. Antimicrobial peptides (AMPs) are emerging as novel and effective non-antibiotic tools to combat infectious diseases in poultry. In this study, we evaluated six avian AMPs including 2 truncated cathelicidins, [CATH-1(6–26) and CATH-2(1–15)], and 4 avian β-defensins (ABD1, 2, 6 and 9) for their bactericidal and immunomodulatory activities. Our findings have shown CATH-1(6–26) and ABD1 being the two most potent avian AMPs effective against Gram-positive and Gram-negative bacteria investigated in these studies. Moreover, CATH-1(6–26) inhibited LPS-induced NO production and exhibited dose-dependent cytotoxicity to HD11 cells. While, ABD1 blocked LPS-induced IL-1β gene induction and was non-toxic to HD11 cells. Importantly, in ovo administration of these AMPs demonstrated that ABD1 can offer significant protection from early chick mortality (44% less mortality in ABD1 treated group versus the control group) due to the experimental yolk sac infection caused by avian pathogenic Escherichia coli. Our data suggest that in ovo administration of ABD1 has immunomodulatory and anti-infection activity comparable with CpG ODN. Thus, ABD1 can be a significant addition to potential alternatives to antibiotics for the control of bacterial infections in young chicks.