Cross-Protection Conferred by Combined Vaccine Containing Infectious Bronchitis Virus Attenuated Massachusetts and Recombinant LaSota Virus Expressing Arkansas Spike.

We previously demonstrated that a prime-boost regime with an infectious bronchitis virus (IBV) Massachusetts (Mass)-type vaccine and recombinant LaSota virus (rLS) coexpressing IBV Arkansas (Ark)-type trimeric spike ectodomain (Se) and granulocyte macrophage colony stimulating factor (GMCSF) enhances heterologous protection against virulent Ark challenge. This study evaluates protection against Ark-type challenge conferred by administering the rLS/ArkSe.GMCSF and the attenuated Mass viruses mixed in the same vial as a combined vaccine.

Protection Against Infectious Bronchitis Virus Vaccine Recombinants and Chicken-Selected Vaccine Subpopulations.

Outbreaks of infectious bronchitis (IB) continue to occur from novel variants of IB virus (IBV) emerging from selection of vaccine subpopulations and/or naturally occurring recombination events. S1 sequencing of Arkansas (Ark) -type viruses obtained from clinical cases in Alabama broilers and backyard chickens shows both Ark Delmarva Poultry Industry (ArkDPI) vaccine subpopulations as well as Ark vaccine viruses showing recombination with other IB vaccine viruses. IB Ark-type isolates AL5, most similar to an ArkDPI vaccine subpopulation selected in chickens, AL4, showing a cluster of three nonsynonymous changes from ArkDPI subpopulations selected in chickens, and AL9, showing recombination with Massachusetts (Mass) -type IBV, were examined for pathogenicity and ability to break through immunity elicited by vaccination with a commercial ArkDPI vaccine.

Distribution of Infectious Bronchitis Virus Resistance in a Naïve Chicken Population.

Resistance to infectious bronchitis (IB) is a polygenic trait, but little is known about how resistance distributes in the host population. In this study, a relatively large number (n = 369) of specific-pathogen-free white leghorn chickens () were challenged with an Arkansas -type virulent IB virus (IBV), and resistance was evaluated 5 days after challenge by viral load (IBV RNA) in the trachea and cecal tonsils, as well as by tracheal histomorphometry (mucosal thickness and lymphocyte infiltration). Contrary to expectations, results showed a non-Gaussian distribution of resistance of the whole population against challenge.

Global Control of Infectious Bronchitis Requires Replacing Live Attenuated Vaccines by Alternative Technologies.

Despite continuous and extensive efforts to control infectious bronchitis (IB) throughout the century, the disease continues to be one of the most economically relevant diseases affecting the poultry production worldwide. Since the early 1990s, numerous scientists have explicitly warned about the role of attenuated vaccines on IB virus (IBV) evolution and the detrimental consequences of their use to the poultry industry. Herein, we review evidence indicating that the use of live vaccines increases genetic/phenotypic diversity of IBV, enhances their fitness in the environment, and ultimately aggravates and perpetuates the problem for the poultry industry.

Minding the curve: The influence of social origin on earnings inequality by education in Mexico.

Relying on data from the Mexican Mobility Survey for 2006, I evaluate by how much earnings inequality improves upon reducing the influence of social origin on educational attainment. A semiparametric estimation of a counterfactual distribution is used to simulate a distribution of earnings that is not overdetermined by the effect of social origin on education. The contrast between the simulated and the observed distribution reveals that social origin worsens inequality by inducing an earnings bonus.

Infectious Bronchitis Virus Immune Responses in the Harderian Gland upon Initial Vaccination.

In recent years, Arkansas Delmarva Poultry Industry (ArkDPI)-derived infectious bronchitis (IB) virus (IBV) vaccines have been used to characterize the immune responses of chickens subsequent to vaccination on day of hatch or beyond. Perhaps because ArkDPI vaccines display increased heterogeneity, the results on cell immune responses have shown ambiguity. In the current study, we investigated the effects of vaccination with a highly stable and homogeneous Massachusetts (Mass)-type vaccine on days 1 or 7 of age on Harderian gland (HG) responses.

Infectious Bronchitis Virus Population Structure Defines Immune Response and Protection.

A commercial Arkansas (Ark) Delmarva Poultry Industry (DPI)-type vaccine and a more homogeneous population of that vaccine obtained previously through adaptation to chicken embryo kidney (CEK) cells (CEK-ArkDPI) were used as a model to further understand the impact of population genetic structure on generation of immune responses and protection. In a first experiment, vaccinated chickens were challenged with an IBV Ark99-type virulent strain (AL/4614/98). Despite extensive sequence similarity between the vaccines, the more heterogeneous commercial ArkDPI was more efficient at reducing viral loads in challenged chickens, while respiratory signs and tracheal lesions were reduced similarly by either vaccine.

Limited Protection Conferred by Recombinant Newcastle Disease Virus Expressing Infectious Bronchitis Spike Protein.

Recombinant Newcastle disease virus (NDV) LaSota (LS) expressing secreted trimeric spike (S)-ectodomain (Se) of infectious bronchitis virus (IBV) (rLS/IBV.Se) was developed and evaluated for protection conferred against IBV challenge. The IBV S-ectodomain protein, which is S excluding the transmembrane anchor and short cytoplasmic domain of S2, expressed from recombinant LS corresponds to an Arkansas (Ark)-type IBV.

Infectious Bronchitis Virus Vaccination at Day 1 of Age Further Limits Cross Protection.

Cross-protection and immune responses elicited by infectious bronchitis virus (IBV) vaccination on Day 1 of age or at later time points were examined. Specific-pathogen-free chickens were vaccinated with a Massachusetts-type vaccine and heterologous challenge was performed with an Arkansas (Ark) -type virulent strain. In Trial 1, chickens vaccinated on Day 1 or Day 10 of age were challenged 21 days after vaccination.

Early Vaccination of Chickens Induces Suboptimal Immunity Against Infectious Bronchitis Virus.

Infectious bronchitis virus (IBV) is highly prevalent in broiler chickens despite extensive vaccination commonly conducted early after hatch. The effects of early vaccination on immune responses were further investigated in chickens primed at increasing ages, followed by booster vaccination with an attenuated Arkansas (Ark) Delmarva Poultry Industry-type vaccine. Results show that vaccination on day 1 of age elicits significantly lower systemic and mucosal antibody responses compared with vaccination at later time points in the life of the chicken.

Gallbladder ascariasis in Kosovo - focus on ultrasound and conservative therapy: a case series.

Background: Ascaris lumbricoides is one of the most common intestinal infections in developing countries, including Kosovo. In contrast to migration to the bile duct, migration of the worm to the gallbladder, due to the narrow and tortuous nature of the cystic duct, is rare. When it does occur, it incites acalculous cholecystitis.

Infectious Bronchitis Virus S2 of 4/91 Expressed from Recombinant Virus Does Not Protect Against Ark-Type Challenge.

We previously demonstrated that chickens primed with a recombinant Newcastle disease virus LaSota (rLS) expressing the S2 gene of infectious bronchitis virus (IBV) and boosted with an attenuated IBV Massachusetts (Mass)-type vaccine were protected against IBV Arkansas (Ark)-type virulent challenge. A possible basis for the reported ability of IBV 4/91 (serotype 793/B) vaccine to protect against divergent IBV strains (e.g.

Protection against infectious bronchitis virus by spike ectodomain subunit vaccine.

The avian coronavirus infectious bronchitis virus (IBV) S1 subunit of the spike (S) glycoprotein mediates viral attachment to host cells and the S2 subunit is responsible for membrane fusion. Using IBV Arkansas-type (Ark) S protein histochemistry, we show that extension of S1 with the S2 ectodomain improves binding to chicken tissues. Although the S1 subunit is the major inducer of neutralizing antibodies, vaccination with S1 protein has been shown to confer inadequate protection against challenge.

Kidney Cell-Adapted Infectious Bronchitis ArkDPI Vaccine is Stable and Protective.

We previously demonstrated that adaptation of an embryo-attenuated infectious bronchitis virus (IBV) Arkansas (Ark) Delmarva Poultry Industry (DPI)-derived vaccine to chicken embryo kidney (CEK) cells (CEKp7) shifted the virus population towards homogeneity in spike (S) and nonstructural protein genes. Moreover, the typical Ark vaccine subpopulations emerging in chickens vaccinated with commercial Ark vaccines were not detected in chickens vaccinated with CEKp7, indicating that kidney-cell adaptation drastically increased the stability of the vaccine virus population in chickens. In the current study both conventional and next-generation sequencing results show that the changes achieved during CEK adaptation remained after five back passages in embryonated chicken egg (ECE).

Inactivation of Avian Influenza Virus in Nonpelleted Chicken Feed.

Corn stored outside could become contaminated with avian influenza virus (AIV) from wild bird droppings. AIV-contaminated ingredients could pass into the poultry flocks in nonpelleted chicken feed. The efficacy of two disinfectants at inactivating AIV in chicken feed was evaluated.

Variability Assessment of California Infectious Bronchitis Virus Variants.

On the basis of the data from the California Animal Health and Food Safety Laboratory System, 1444 infectious bronchitis (IB) cases were diagnosed between 1997 and 2012. Epidemiologic analyses demonstrated two major IB virus (IBV) outbreak peaks, affecting mainly 35-to-49-day-old broiler chickens. California variant 1737 (CA1737) and California variant 1999 (Cal 99) IBV types were the most prevalent genotypes during the analyzed period.

Kidney Cell-Adapted Infectious Bronchitis Virus Arkansas Delmarva Poultry Industry Vaccine Confers Effective Protection Against Challenge.

We previously demonstrated that adaptation of an embryo-attenuated infectious bronchitis virus (IBV) Arkansas Delmarva Poultry Industry (ArkDPI)-derived vaccine to chicken embryo kidney (CEK) cells shifted the virus population towards homogeneity in spike (S) and nonstructural protein genes. Moreover, the typical Ark vaccine subpopulations emerging in chickens vaccinated with commercial Ark vaccines were not detected in chickens vaccinated with the CEK-adapted virus. In this study, chickens vaccinated with a low dose (1.

Cross-Protection by Infectious Bronchitis Viruses Under Controlled Experimental Conditions.

Infectious bronchitis virus (IBV) cross-protection trials were performed in healthy chickens maintained under controlled environmental conditions. Chickens primed or primed and boosted with a Massachusetts (Mass)-type attenuated vaccine were subsequently challenged with either IBV Arkansas (Ark) or GA13-type virulent strains. In addition, Ark-vaccinated chickens were challenged with IBV GA13.

Effects of Adaptation of Infectious Bronchitis Virus Arkansas Attenuated Vaccine to Embryonic Kidney Cells.

The population structure of an embryo-attenuated infectious bronchitis virus (IBV) Arkansas (Ark) Delmarva Poultry Industry (DPI)-derived vaccine was characterized during serial passages in chicken embryo kidney (CEK) cells and after back-passage in embryonated chicken eggs (ECE) and in chickens. Both conventional and deep-sequencing results consistently showed population changes occurred during adaptation to CEK cells. Specifically, 13 amino acid (aa) positions seemed to be targets of selection when comparing the vaccine genome prior to and after seven passages in CEK (CEKp7).

Combined infectious bronchitis virus Arkansas and Massachusetts serotype vaccination suppresses replication of Arkansas vaccine virus.

Polyvalent infectious bronchitis virus vaccination is common worldwide. The possibility of vaccine interference after simultaneous combined vaccination with Arkansas (Ark) and Massachusetts (Mass)-type vaccines was evaluated in an effort to explain the high prevalence of Ark-type infectious bronchitis virus in vaccinated chickens. Chickens ocularly vaccinated with combinations of Ark and Mass showed predominance of Mass vaccine virus before 9 days post-vaccination (DPV) in tears.

Immunoglobulin A as an early humoral responder after mucosal avian coronavirus vaccination.

Infectious bronchitis virus (IBV) is a highly contagious coronavirus prevalent in all countries with an extensive poultry industry and continues to cause economic losses. IBV strains of the Ark serotype are highly prevalent in the Southeastern United States despite extensive vaccination. One explanation for this observation is the high genetic variability of IBV.

S1 of distinct IBV population expressed from recombinant adenovirus confers protection against challenge.

Protective properties of three distinct infectious bronchitis virus (IBV) Ark Delmarva poultry industry (ArkDPI) S1 proteins encoded from replication-defective recombinant adenovirus vectors were investigated. Using a suboptimal dose of each recombinant virus, we demonstrated that IBV S1 amino acid sequences showing > or = 95.8% amino acid identity to the S1 of the challenge strain differed in their ability at conferring protection.