scholarly journals Effect of Pullet Vaccination on Development and Longevity of Immunity

Viruses ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 135 ◽  
Author(s):  
Emily Aston ◽  
Brian Jordan ◽  
Susan Williams ◽  
Maricarmen García ◽  
Mark Jackwood
Keyword(s):  
Clinical Signs ◽  
Vaccination Program ◽  
Economic Losses ◽  
Respiratory Pathogens ◽  
Infectious Laryngotracheitis Virus ◽  
Vaccination Programs ◽  
Live Attenuated Vaccines ◽  
Specific Pathogen ◽  
Infectious Laryngotracheitis ◽  
Laryngotracheitis Virus

Avian respiratory disease causes significant economic losses in commercial poultry. Because of the need to protect long-lived poultry against respiratory tract pathogens from an early age, vaccination programs for pullets typically involve serial administration of a variety of vaccines, including infectious bronchitis virus (IBV), Newcastle disease virus (NDV), and infectious laryngotracheitis virus (ILTV). Often the interval between vaccinations is only a matter of weeks, yet it is unknown whether the development of immunity and protection against challenge when vaccines are given in short succession occurs in these birds, something known as viral interference. Our objective was to determine whether serially administered, live attenuated vaccines against IBV, NDV, and ILTV influence the development and longevity of immunity and protection against challenge in long-lived birds. Based on a typical pullet vaccination program, specific-pathogen-free white leghorns were administered multiple live attenuated vaccines against IBV, NDV, and ILTV until 16 weeks of age (WOA), after which certain groups were challenged with IBV, NDV, or ILTV at 20, 24, 28, 32, and 36 WOA. Five days post-challenge, viral load, clinical signs, ciliostasis, tracheal histopathology, and antibody titers in serum and tears were evaluated. We demonstrate that pullets serially administered live attenuated vaccines against IBV, NDV, and ILTV were protected against homologous challenge with IBV, NDV, or ILTV for at least 36 weeks, and conclude that the interval between vaccinations used in this study (at least 2 weeks) did not interfere with protection. This information is important because it shows that a typical pullet vaccination program consisting of serially administered live attenuated vaccines against multiple respiratory pathogens can result in the development of protective immunity against each disease agent.

scholarly journals Evaluation of Recombinant Herpesvirus of Turkey Laryngotracheitis (rHVT-LT) Vaccine against Genotype VI Canadian Wild-Type Infectious Laryngotracheitis Virus (ILTV) Infection

Vaccines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1425
Author(s):  
Catalina Barboza-Solis ◽  
Shahnas M. Najimudeen ◽  
Ana Perez-Contreras ◽  
Ahmed Ali ◽  
Tomy Joseph ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Clinical Signs ◽  
Wild Type ◽  
Infectious Laryngotracheitis Virus ◽  
Peripheral Blood Mononuclear ◽  
Live Attenuated Vaccine ◽  
Common Causes ◽  
Specific Pathogen ◽  
Infectious Laryngotracheitis ◽  
Laryngotracheitis Virus

In Alberta, infectious laryngotracheitis virus (ILTV) infection is endemic in backyard poultry flocks; however, outbreaks are only sporadically observed in commercial flocks. In addition to ILTV vaccine revertant strains, wild-type strains are among the most common causes of infectious laryngotracheitis (ILT). Given the surge in live attenuated vaccine-related outbreaks, the goal of this study was to assess the efficacy of a recombinant herpesvirus of turkey (rHVT-LT) vaccine against a genotype VI Canadian wild-type ILTV infection. One-day-old specific pathogen-free (SPF) White Leghorn chickens were vaccinated with the rHVT-LT vaccine or mock vaccinated. At three weeks of age, half of the vaccinated and the mock-vaccinated animals were challenged. Throughout the experiment, weights were recorded, and feather tips, cloacal and oropharyngeal swabs were collected for ILTV genome quantification. Blood was collected to isolate peripheral blood mononuclear cells (PBMC) and quantify CD4+ and CD8+ T cells. At 14 dpi, the chickens were euthanized, and respiratory tissues were collected to quantify genome loads and histological examination. Results showed that the vaccine failed to decrease the clinical signs at 6 days post-infection. However, it was able to significantly reduce ILTV shedding through the oropharyngeal route. Overall, rHVT-LT produced a partial protection against genotype VI ILTV infection.

scholarly journals Pathogenic and Transmission Potential of Wildtype and Chicken Embryo Origin (CEO) Vaccine Revertant Infectious Laryngotracheitis Virus

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 541
Author(s):  
Ana Perez-Contreras ◽  
Catalina Barboza-Solis ◽  
Shahnas M. Najimudeen ◽  
Sylvia Checkley ◽  
Frank van der Meer ◽  
...  
Keyword(s):  
Chicken Embryo ◽  
Severe Disease ◽  
Clinical Signs ◽  
Upper Respiratory Tract ◽  
Infectious Laryngotracheitis Virus ◽  
Live Attenuated Vaccines ◽  
Transmission Potential ◽  
Infectious Laryngotracheitis ◽  
Laryngotracheitis Virus ◽  
Embryo Origin

Infectious laryngotracheitis (ILT) is an infectious upper respiratory tract disease that impacts the poultry industry worldwide. ILT is caused by an alphaherpesvirus commonly referred to as infectious laryngotracheitis virus (ILTV). Vaccination with live attenuated vaccines is practiced regularly for the control of ILT. However, extensive and improper use of live attenuated vaccines is related to vaccine viruses reverting to virulence. An increase in mortality and pathogenicity has been attributed to these vaccine revertant viruses. Recent studies characterized Canadian ILTV strains originating from ILT outbreaks as related to live attenuated vaccine virus revertants. However, information is scarce on the pathogenicity and transmission potential of these Canadian isolates. Hence, in this study, the pathogenicity and transmission potential of two wildtype ILTVs and a chicken embryo origin (CEO) vaccine revertant ILTV of Canadian origin were evaluated. To this end, 3-week-old specific pathogen-free chickens were experimentally infected with each of the ILTV isolates and compared to uninfected controls. Additionally, naïve chickens were exposed to the experimentally infected chickens to mimic naturally occurring infection. Pathogenicity of each of these ILTV isolates was evaluated by the severity of clinical signs, weight loss, mortality, and lesions observed at the necropsy. The transmission potential was evaluated by quantification of ILTV genome loads in oropharyngeal and cloacal swabs and tissue samples of the experimentally infected and contact-exposed chickens, as well as in the capacity to produce ILT in contact-exposed chickens. We observed that the CEO vaccine revertant ILTV isolate induced severe disease in comparison to the two wildtype ILTV isolates used in this study. According to ILTV genome load data, CEO vaccine revertant ILTV isolate was successfully transmitted to naïve contact-exposed chickens in comparison to the tested wildtype ILTV isolates. Overall, the Canadian origin CEO vaccine revertant ILTV isolate possesses higher virulence, and dissemination potential, when compared to the wildtype ILTV isolates used in this study. These findings have serious implications in ILT control in chickens.

scholarly journals Detection of Laryngotracheitis Virus in Poultry Flocks with Respiratory Disorders in Slovenia

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 707
Author(s):  
Olga Zorman Rojs ◽  
Alenka Dovč ◽  
Uroš Krapež ◽  
Zoran Žlabravec ◽  
Joško Račnik ◽  
...  
Keyword(s):  
Economic Losses ◽  
Respiratory Pathogens ◽  
Upper Respiratory Tract ◽  
Severe Condition ◽  
Live Virus ◽  
Respiratory Disorders ◽  
Infectious Bronchitis ◽  
Infectious Laryngotracheitis ◽  
Laryngotracheitis Virus ◽  
Ornithobacterium Rhinotracheale

Infectious laryngotracheitis (ILT) is an acute, highly contagious infectious disease of the upper respiratory tract in chickens and other poultry species that causes significant economic losses in countries worldwide. Between 2017 and 2019, seven outbreaks of mild to severe respiratory disorders with high suspicion of ILT occurred in commercial and backyard poultry flocks in Slovenia. In all submissions, infection with ILT virus (ILTV) was confirmed by PCR, which is the first report of ILT in Slovenia. Circulating ILT strains were characterized by the sequence and phylogenetic analysis of two fragments of the ICP4 gene. Four strains—three detected in non-vaccinated flocks and one in a flock vaccinated against ILT—were identical or very similar to the chicken embryo–origin live virus vaccines, and the other three were closely related to Russian, Chinese, Australian, and American field strains and to tissue culture origin vaccine strains. As in other diseases, coinfections with other respiratory pathogens in confirmed ILT cases may cause a more severe condition and prolong the course of the disease. In our study, coinfections with Mycoplasma synoviae (7/7 tested flocks), infectious bronchitis virus (5/5 tested flocks), Mycoplasma gallisepticum (4/7 tested flocks), Ornithobacterium rhinotracheale (3/4 tested flocks), and avian pox virus (1/2 tested flocks) were confirmed, indicating the importance of these pathogens in the occurrence of ILT infections.

scholarly journals Experimental infection on the locally isolated avian infectious laryngotracheitis virus

2017 ◽  
Vol 41 (1) ◽  
pp. 1-4
Author(s):  
Zaid Haddam Taha
Keyword(s):  
Experimental Infection ◽  
Post Infection ◽  
Clinical Signs ◽  
Elisa Test ◽  
Infected Group ◽  
Control Group ◽  
Infectious Laryngotracheitis Virus ◽  
Infectious Laryngotracheitis ◽  
Laryngotracheitis Virus ◽  
And Control

     The aim of this study was to evaluate virulence of local isolated avian infectious laryngotracheitis virus in experimentally infected chicken. Forty chickens 10 weeks old were used for the experimental infection with the locally isolated infectious laryngotracheitis virus. Chickens were divided into three groups, the first group consisted from 20 chickens infected with isolated infectious laryngotracheitis virus (2×104.16 TCID 50/50 µl) via eyes and mouth drops (one drop for each). The second group consisted of 10 chickens (non-infected) in contact with infected group inoculated with maintenance media (Minimum essential medium) on their eyes, to observe if the infected group can spread the virus. The third group consisted from 10 chickens (non-infected) were left as a control group separated from other groups, inoculated with maintenance media (Minimum essential medium) on their eyes. Clinical signs and mortality were examined daily up to 12 days post infection. The main clinical signs were depression coughing and gasping with mild conjunctivitis and no mortality. Enzyme linked immunosorbent assay (ELISA) test was conducted on the collected sera of chickens before and after experimental infection with isolated virus. The results of ELISA test was negative for all groups of chickens before experiment  and positive results for infected group with titer approximately ranging from (2534-7910); Measure of central tendency and dispersion were used with mean (4874.75) and stander error (355.96\ 13.6%); while negative results for contact group and control group. Eighteen chickens (10 weeks old) separately were divided into three groups (infected, contact and control) treated as mention above  and were used   for histopathological examination; the chickens were killed, two in each group at 24 hr., 48 hr. and 72 hr. post infection. The histopathological changes on trachea and larynx were intracellur inclusion bodies formation detected at 72hr., post infection for infected group only.

scholarly journals Molecular detection and genetic characterization of infectious laryngotracheitis virus in poultry in Myanmar

2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Zhiyuan Yang ◽  
Shiro Murata ◽  
Sotaro Fujisawa ◽  
Masaki Takehara ◽  
Ken Katakura ◽  
...  
Keyword(s):  
Molecular Detection ◽  
Genetic Characterization ◽  
Cell Protein ◽  
Economic Losses ◽  
Sequencing Analysis ◽  
Asian Countries ◽  
Infectious Laryngotracheitis Virus ◽  
Poultry Farms ◽  
Infectious Laryngotracheitis ◽  
Laryngotracheitis Virus

Abstract Background Avian infectious laryngotracheitis (ILT) is a highly contagious viral disease that causes severe economic losses to the poultry industry worldwide. In Southeast Asian countries, including Myanmar, poultry farming is a major industry. Although it is known that infectious respiratory pathogens, including infectious laryngotracheitis virus (ILTV), are a major threat to poultry farms, there are no data currently available on the epidemiology of ILTV in Myanmar. Therefore, in this study, we conducted a molecular detection of ILTV in 20 poultry farms in Myanmar. Results Of the 57 tested oropharyngeal swabs, 10 were positive for ILTV by polymerase chain reaction of a 647 bp region of the thymidine kinase (TK) gene, giving a prevalence of ILTV of 17.5% (10/57). Further sequencing analysis of infected cell protein 4 (ICP4) gene and glycoprotein B, G, and J (gB, gG, and gJ) genes indicated that these isolates were field strains. Phylogenetic analysis revealed that the Myanmar strains clustered together in a single branch and were closely related to other reference strains isolated from Asian countries. Conclusions This study demonstrated the presence of ILTV in poultry farms in Myanmar. The genetic characterization analysis performed provides the fundamental data for epidemiological studies that monitor circulating strains of ILTV in Myanmar.

scholarly journals Immunoinformatics Approach for Multiepitopes Vaccine Prediction against Glycoprotein B of Avian Infectious Laryngotracheitis Virus

2019 ◽  
Vol 2019 ◽  
pp. 1-23 ◽  
Author(s):  
Sumaia A. Ali ◽  
Yassir A. Almofti ◽  
Khoubieb A. Abd-elrahman
Keyword(s):  
B Cell ◽  
Glycoprotein B ◽  
Economic Losses ◽  
Upper Respiratory Tract ◽  
Infectious Laryngotracheitis Virus ◽  
B Cell Epitopes ◽  
Mhc Ii ◽  
High Affinity ◽  
Infectious Laryngotracheitis ◽  
Laryngotracheitis Virus

Infectious laryngotracheitis virus (ILTV) is a gallid herpesvirus type 1, a member of the genus Iltovirus. It causes an infection in the upper respiratory tract mainly trachea which results in significant economic losses in the poultry industry worldwide. Vaccination against ILTV produced latent infected carriers’ birds, which become a source of virus transmission to nonvaccinated flocks. Thus this study aimed to design safe multiepitopes vaccine against glycoprotein B of ILT virus using immunoinformatic tools. Forty-four sequences of complete envelope glycoprotein B were retrieved from GenBank of National Center for Biotechnology Information (NCBI) and aligned for conservancy by multiple sequence alignment (MSA). Immune Epitope Database (IEDB) analysis resources were used to predict and analyze candidate epitopes that could act as a promising peptide vaccine. For B cell epitopes, thirty-one linear epitopes were predicted using Bepipred. However eight epitopes were found to be on both surface and antigenic epitopes using Emini surface accessibility and antigenicity, respectively. Three epitopes (190KKLP193, 386YSSTHVRS393, and 317KESV320) were proposed as B cell epitopes. For T cells several epitopes were interacted with MHC class I with high affinity and specificity, but the best recognized epitopes were 118YVFNVTLYY126, 335VSYKNSYHF343, and 622YLLYEDYTF630. MHC-II binding epitopes, 301FLTDEQFTI309,277FLEIANYQV285, and 743IASFLSNPF751, were proposed as promising epitopes due to their high affinity for MHC-II molecules. Moreover the docked ligand epitopes from MHC-1 molecule exhibited high binding affinity with the receptors; BF chicken alleles (BF2 2101 and 0401) expressed by the lower global energy of the molecules. In this study nine epitopes were predicted as promising vaccine candidate against ILTV. In vivo and in vitro studies are required to support the effectiveness of these predicted epitopes as a multipeptide vaccine through clinical trials.

scholarly journals Glycoprotein G is a virulence factor in infectious laryngotracheitis virus

2006 ◽  
Vol 87 (10) ◽  
pp. 2839-2847 ◽  
Author(s):  
J. M. Devlin ◽  
G. F. Browning ◽  
C. A. Hartley ◽  
N. C. Kirkpatrick ◽  
A. Mahmoudian ◽  
...  
Keyword(s):  
Virulence Factor ◽  
Clinical Signs ◽  
Pcr Analysis ◽  
Infectious Laryngotracheitis Virus ◽  
Glycoprotein G ◽  
Infectious Laryngotracheitis ◽  
Laryngotracheitis Virus

Infectious laryngotracheitis virus (ILTV; Gallid herpesvirus 1) is an alphaherpesvirus that causes acute respiratory disease in chickens. The role of glycoprotein G (gG) in vitro has been investigated in a number of alphaherpesviruses, but the relevance of gG in vivo in the pathogenicity of ILTV or in other alphaherpesviruses is unknown. In this study, gG-deficient mutants of ILTV were generated and inoculated into specific-pathogen-free chickens to assess the role of gG in pathogenicity. In chickens, gG-deficient ILTV reached a similar titre to wild-type (wt) ILTV but was significantly attenuated with respect to induction of clinical signs, effect on weight gain and bird mortality. In addition, an increased tracheal mucosal thickness, reflecting increased inflammatory cell infiltration at the site of infection, was detected in birds inoculated with gG-deficient ILTV compared with birds inoculated with wt ILTV. The reinsertion of gG into gG-deficient ILTV restored the in vivo phenotype of the mutant to that of wt ILTV. Quantitative PCR analysis of the expression of the genes adjacent to gG demonstrated that they were not affected by the deletion of gG and investigations in vitro confirmed that the phenotype of gG-deficient ILTV was consistent with unaltered expression of these adjacent genes. This is the first reported study to demonstrate definitively that gG is a virulence factor in ILTV and that deletion of gG from this alphaherpesvirus genome causes marked attenuation of the virus in its natural host.

scholarly journals Molecular epidemiology of respiratory viruses in commercial chicken flocks in Pakistan from 2014 through to 2016

2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Sajid Umar ◽  
Angélique Teillaud ◽  
Hassan Bin Aslam ◽  
Jean-Luc Guerin ◽  
Mariette F. Ducatez
Keyword(s):  
Respiratory Viruses ◽  
Control Measures ◽  
Economic Losses ◽  
Infectious Laryngotracheitis Virus ◽  
Respiratory Problems ◽  
Infectious Bronchitis ◽  
Commercial Chicken ◽  
Infectious Laryngotracheitis ◽  
Commercial Poultry ◽  
Laryngotracheitis Virus

Abstract Background Viral diseases are a matter of great concern for poultry farmers in Pakistan. Multiple common viral respiratory diseases (CVRDs) cause huge economic losses in the poultry industry. The prevalence of CVRDs in many countries, including Pakistan, is not clearly understood. Results Incidences of 5 chicken respiratory viruses: avian influenza virus (AIV), Newcastle disease virus (NDV/AAVV-1), infectious bronchitis virus (IBV), avian metapneumovirus (aMPV) and infectious laryngotracheitis virus (ILTV) were assessed on commercial Pakistani farms with respiratory problems from 2014 through to 2016. While AIV and AAVV-1 were frequently detected (16 to 17% of farms), IBV and aMPV were rarely detected (in 3 to 5% of farms) and ILTV was not detected. We characterized H9 AIV of the G1 lineage, genotype VII AAVV-1, GI-13 IBV, and type B aMPV strains with very little genetic variability in the 2-year study period. Co-infections with AIV and AAVV-1 were common and wild type AAVV-1 was detected despite the use of vaccines. Control measures to limit the virus burden in chicken flocks are discussed. Conclusions Our data shows that AIV (H9), AAVV-1, IBV and aMPV are prevalent in commercial poultry in Pakistan. Further studies are necessary to assess circulating strains, economic losses caused by infections and coinfections of these pathogens, and the costs and benefits of countermeasures. Furthermore, veterinarians and farmers should be informed of the pathogens circulating in the field and hence advised on the use of vaccines.

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