Co-circulation of three clusters of 793/B-like avian infectious bronchitis virus genotypes in Iranian chicken flocks.
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ABSTRACT:
SUBMITTER: Kalokhoran AY
PROVIDER: S-EPMC7086655 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Infectious bronchitis virus (IBV) is a highly infectious pathogen, which affects the respiratory tract, reproductive system, and kidney of chickens. Many different genotypes of IBV are recognized which cause different clinical manifestations. According to the antigenic differences, different serotypes of the virus do not cross-protect. Massachusetts serotype induces the best cross-protection against other serotypes. Recently, the IBV QX genotype has been detected in Iran. QX genotype causes permanent damage to the oviduct in layer and breeder flock if it occurs in the early life cycle. In this study, we compared two vaccination program using 793/B type and Massachusetts type vaccine. One-day-old SPF chickens were divided into four groups. Groups 1 and 2 were unvaccinated groups. Group 3 was vaccinated with the H120 vaccine at day 1 and 793/B at day 14 (eye drop), and group 4 was vaccinated with H120+793/B (eye drop) on the first day and 793/B at day 14. Groups 2, 3, and 4 challenged (oculonasal) with QX genotype (104 EID50) at day 35. Five days post challenge, the sample were clollected for ciliostasis test, histopathology, and quantitative real-time RT-PCR from trachea, lung, and kidneys. Results showed that two vaccination programs created more than 80% of protection against challenge virus, but no significant difference was recorded between two programs. Based on our results, it can be concluded that vaccination with two mixed vaccines (H120+793/B) on the first day of the life of a chick does not make any difference in comparison to single vaccine (H120) in reducing of pathological damages and viral load. As long as the second vaccination against IB may not be applied properly in farm situation, applying the mixture of 793/B type vaccine with H120 at day 1 (ocular or spray) may help to increase vaccination program efficacy.
| S-EPMC7088605 | biostudies-literature
Project description:Background: Infectious bronchitis virus (IBV), a major pathogen of commercial poultry flocks, circulates in the form of several serotypes/genotypes. Only a few amino-acid changes in the S1 subunit of wild-type IBVS proteins may result in mutants unaffected by current vaccines.Methods: Partial S1 gene sequences of 3 IBV isolates of the Moroccan Italy 02 genotype from vaccinated and unvaccinated broiler chicken flocks, located in southern and central regions of Morocco, were amplified by RT-PCR, sequenced, and aligned for phylogenetic and amino-acid similarity analyses.Results: The three isolates were found genetically highly distant from known avian IBV based on partial sequences of their S1 genes: gammaCoV/chicken/Morocco/I01/2011(IBV/Morocco/01), gammaCoV/chicken/Morocco/I30/2010 (IBV/Morocco/30), and gammaCoV/chicken/Morocco/I38/2013 (IBV/Morocco/38), nucleotide sequence identities reached 89.5 % to 90.9 % among the three isolates. The deduced protein sequence identities ranged from 29.7 % (between IBV/Morocco/38 and Egypt SCU-14/2013-1) to 78.2 % (between IBV/Morocco/01 and Spain/05/866). Amino acid sequence comparison and phylogenetic analysis indicated the emergence of a new Moroccan genotype, clustering with regionally related isolates from Spain (Spain/05/866) and belonging to a new sub-genotype.Conclusion: Our sequencing results demonstrate a co-circulation of wild-type infectious bronchitis viruses in broiler chickens. These results justify permanent monitoring of circulating strains in order to rationally modify vaccination strategies to make them appropriate to the evolving field situation.
| S-EPMC4524495 | biostudies-literature
Project description:Infectious Bronchitis (IB) is an acute, highly contagious disease associated with respiratory signs in young chickens and reduced egg production and quality in layers. The purpose of this study was to isolate and identify the infectious bronchitis virus in broiler flocks with respiratory diseases in four provinces of Iran. The specimens from forty IB suspected flocks from different regions of Isfahan, East Azerbaijan, Golestan, and Khuzestan provinces were collected, and the trachea, lung, and cecal tonsils were sampled. The samples were inoculated into 9- to 11-day-old embryonated chicken eggs. After collecting the allantoic fluid, RT-PCR was carried out to detect IB viruses. The results showed that IBVs were isolated from 30% of the flocks in these four provinces. The positive samples, according to a partial S1 gene sequence, were more investigated. Comparing nucleotide and amino acid sequences showed that the four isolates had the most similarity to the Pakistani 793/B strain (GI-13 lineage). The three isolates had the most considerable similarity in amino acid and nucleotide sequences to Iraqi and Iranian QX-like viruses (GI-19 lineage). Two isolates had 96 to 98% resemblance to Iranian variant-2 (GI-23 lineage) isolates. One isolate was found to belong to the Massachusetts serotype (GI-1 lineage) having 100% similarity in its amino acid sequence to the Massachusetts serotypes in GenBank. The phylogenetic relationship of the isolates shows complexity and diversity concerning different sequences and geographical regions.
| S-EPMC7474476 | biostudies-literature
Project description:In this study, 20 infectious bronchitis virus (IBV) strains, which were genotypically related to 793/B, as assessed by an S1 gene comparison and a complete genomic sequence analysis, were isolated and identified from 2009 to 2014 in China. Phylogenetic analysis, network tree, similarity plot analysis, Recombination Detection Program 4(RDP4) and sequence comparison revealed that 12 of the 20 isolates were likely the reisolated vaccine virus. One isolate, ck/CH/LSD/110857, was shown to have originated from recombination events between H120- and 4/91-like vaccine strains that did not result in changes of antigenicity and pathogenicity. The remaining seven IBV isolates were shown to have originated from recombination events between a 4/91-like vaccine strain and a GX-LY9-like virus, which were responsible for the emergence of a novel serotype. A vaccination-challenge test found that vaccination with the 4/91 vaccine strain did not provide protection against challenge with the recombinant viruses. In addition, the results showed that the recombination events between the vaccine and field strains resulted in altered genetics, serotype, antigenicity, and pathogenicity compared with those of their deduced parental viruses. The results are important not only because this virus is of economic importance to poultry industry, but also because it is important for elucidating the origin and evolution of other coronaviruses.
| S-EPMC7117474 | biostudies-literature
Project description:Avian infectious bronchitis (IB) is a major cause of economic losses in poultry industry. The IB virus primarily affects respiratory tract, but various strains differ in their tropism for other target organs such as kidney and alimentary tract. The objective of this study was to estimate the pathogenicity of Iranian IBV variant (IR-1), which is limited exclusively to Iran. Specific pathogen free chicks were inoculated intranasally. Sera, fecal swabs and different tissue samples were collected on different days post infection (DPI). Clinical signs, gross pathology and histological changes were recorded. The viral load was quantified in the RNA extractions from different tissue samples using real-time PCR. Anti-IBV antibodies were detected in serum samples. The IgG antibody were found on 21 and 28 DPI. Severe histological lesions were observed in the trachea and lung while the lesions in kidney were appeared to be milder. Viral RNA was detected in all tested tissues from 1 DPI to the last day of the experiment. The highest viral load was measured in the trachea and feces on 1st and 5th DPI, respectively. It can be concluded the IR-1 had broad tropism for respiratory tract, digestive system, and renal tissue, reflecting its epitheliotropic nature, but it caused the most severe lesions in the respiratory tract. This was the first pathogenicity study of Iranian IR-1 IBV. Further knowledge of IBV pathogenesis provides the groundwork to inform more effective prevention practices.
| S-EPMC5413309 | biostudies-literature
Project description:The nephropathogenic infectious bronchitis virus (IBV) strain IS-1494 like (variant-2; GI-23) was first isolated in the Middle East (1998). Despite intensive vaccinations, IS-1494 like IBVs are still circulating in Iran (the dominant genotype) and spread to other countries. Here, the full-length genome of this Iranian IS-1494 like IBV was (Mahed) determined to understand its evolutionary relationships. The genome consists of 27,652 nucleotides, with mutations in most of the structural genes. Thirteen open reading frames (ORFs) were predicted in the Mahed isolate (5' UTR-1a-1b-S-3a-3b-E-M-4b-4c-5a-5b-N-6b-3' UTR). ORFs 4b, 4c, and 6b, which has rarely been reported, were present in the Mahed genome. According to phylogenetic analysis of the full-length genome, 1a, S2, M, E, N protein, Mahed isolate clustered with the QX type strain. Based on the partial 1b, S1, Mahed clustered with the Q1 strain. The full-length genome of Mahed isolate shared the highest sequence homology with Gray and JMK (90.06-90.07%) and was least related to the Vic-s (86.21%). These data show that evolutionary variation because of recombination in IBV plays a major role in the adaptation and origin of IBV leading to new genetic and types of the virus strain.
| S-EPMC6111945 | biostudies-literature
Project description:Infectious bronchitis (IB) is one of the most important viral diseases of poultry. The aim of this study was to investigate the distribution of avian infectious bronchitis virus isolate IRFIBV32 (793/B serotype) in experimentally infected chicken. Ninety-one-day-old commercial broilers were divided randomly into two groups (seventy in the experimental and twenty in the control group). Chicks in the experimental group were inoculated intranasally with 10(5) ELD50/0.1 mL of the virus at three weeks of age. The samples from various tissues were collected at1, 2, 3, 5, 7, 11, 13, 15, and 20 days postinoculation. Chickens exhibited mild respiratory signs and depression. Viral RNA was detected in the kidney, lung and tracheas on days 1 to 13 PI, in the oviduct between, days 3 and 13, in testes between days 1 and 11 PI, and in the caecal tonsil consistently up to day 20 PI. The most remarkable clinical signs and virus detection appeared on day 1 PI. Data indicated that the number of infected chickens and viral RNA detection from tissues was reduced with increasing antibody titer on day 20 PI. The results demonstrated that the IRFIBV32 virus has wide tissue distribution for respiratory, urogenital, and digestive systems.
| S-EPMC3329954 | biostudies-literature
Project description:Avian infectious bronchitis (IB) is caused by avian infectious bronchitis virus (IBV) belonging to Coronaviridae family. The disease is prevalent in all countries with almost 100% incidence rate. Chicken and commercially reared pheasant are the natural host for IBV. Virus causes respiratory diseases, poor weight gain, feed efficiency in broiler, damage to oviduct, and abnormal egg production in mature hens resulting in economic losses. IBV also replicates in tracheal and renal epithelial cells leading to prominent tracheal and kidney lesions. Virus undergoes spontaneous mutation leading to continual emergence of new variants. The effectiveness of immunization program is diminished because of poor cross-protection among the serotypes. Identification of circulating serotypes is important in controlling IBV infection. Toll-like receptor 3 (TLR3) and TLR21 are involved in early recognition of virus resulting in induction of inflammatory cytokines. Both humoral and cellular immune responses are important in the control of infection. Humoral immunity plays an important role in recovery and clearance of viral infection. IBV-specific cytotoxic T lymphocytes induce lysis of IBV-infected cells. Effective diagnostic tools are required at field level to identify different IBV variants. Embryonated chicken eggs are effective model for virus isolation. Identification by other specific methods like virus neutralization (VN), hemagglutination inhibition (HI), enzyme linked immunosorbent assay (ELISA), immunohistochemistry, or nucleic acid analysis or by electron microscopy is also indispensable. VN test in tracheal organ culture is the best method for antigenic typing for surveillance purposes. Continuous epidemiological surveillance, strict biosecurity measures, and vaccine effective against various serotypes are necessary for controlling IB in chickens.
| S-EPMC7120852 | biostudies-literature
Project description:Background and Objectives:Different epidemiological studies have found that backyard chickens are a reservoir for poultry diseases. Most backyard chicken flocks have a poor level of biosecurity, which increases the risk of spread of diseases. In recent years, the number of backyard chickens has been on the rise in Iran. However, the health status of backyard flocks is still poorly documented. Thus, this study aimed at examining the seroprevalence of antibodies against infectious bronchitis virus (IBV) and molecular surveillance and genotyping of IBV among backyard chickens (without vaccination history) in Mazandaran province, North of Iran, 2014. Materials and Methods:A total of 460 blood samples of unvaccinated backyard chickens in the mentioned area were tested for antibodies against IBV using commercial ELISA. Also, cecal tonsils were collected from 75 chickens in the same area. Real time RT-PCR (for detection) and RT-PCR and sequencing spike gene were performed. Results:The seropositivity rate was 54.5%. In addition, we detected 793/B, Variant 2, and QX in the backyard flocks and performed phylogenetic studies on them. The phylogenetic study revealed that the detected genotypes had high homology with IBV strains that were infected broilers, pullets, and layers in Iran. Conclusion:There is a need for continuous monitoring of IBV among avian species to complete the epidemiological map and work on the pathogenesis of Iranian IBV strains in Iranian backyard chickens.
| S-EPMC6004632 | biostudies-literature
Project description:BackgroundInfectious bronchitis virus (IBV), a prototype of the Coronaviridae family, is an economically important causative agent of infectious bronchitis in chickens and causes an acute and highly contagious upper respiratory tract infections that may lead to nephritis. However, the molecular antiviral mechanisms of chickens to IBV infection remain poorly understood. In this study, we conducted global gene expression profiling of chicken kidney tissue after nephropathogenic IBV infection to better understand the interactions between host and virus.ResultsIBV infection contributed to differential expression of 1777 genes, of which 876 were up-regulated and 901 down-regulated in the kidney compared to those of control chickens and 103 associated with immune and inflammatory responses may play important roles in the host defense response during IBV infection. Twelve of the altered immune-related genes were confirmed by real-time RT-PCR. Gene ontology category, KEGG pathway, and gene interaction networks (STRING analysis) were analyzed to identify relationships among differentially expressed genes involved in signal transduction, cell adhesion, immune responses, apoptosis regulation, positive regulation of the I-kappaB kinase/NF-kappaB cascade and response to cytokine stimulus. Most of these genes were related and formed a large network, in which IL6, STAT1, MYD88, IRF1 and NFKB2 were key genes.ConclusionsOur results provided comprehensive knowledge regarding the host transcriptional response to IBV infection in chicken kidney tissues, thereby providing insight into IBV pathogenesis, particularly the involvement of innate immune pathway genes associated with IBV infection.
| S-EPMC3870970 | biostudies-literature