جستجوی مقالات مرتبط با کلیدواژه "avian infectious bronchitis" در نشریات گروه "دامپزشکی"

Avian infectious bronchitis (IB) is an infectious viral disease of chickens. The effective protection of chickens against many different infectious bronchitis virus (IBV) variants is not achieved unless the circulating genotypes in the region are identified and the cross-protection of the potential of vaccines in use is assessed.

In a monitoring program of IBVs, a new genotype was identified in the north of Iran, 2019. This work was conducted to isolate and characterize this new IBV genotype.

Tracheal tissues were collected from chickens showing signs of respiratory involvement. Specimens were homogenized and inoculated to the allantoic fluid of embryonated specific pathogen-free (SPF) eggs. Infectious bronchitis virus was detected using real time-polymerase chain reaction (RT-PCR). The hypervariable region of the IBV S1 gene was amplified for sequencing.

Positive samples were phylogenetically analyzed, and both positive isolates were clustered with Q1 IBV strains.

This is the first report of the Q1 outbreak in Iran. More investigations are needed to find the role of Q1 IBV in the respiratory disease complex of chickens.

Coronaviruses (AvCoV) which include infectious bronchitis virus (IBV) and other bird coronaviruses belong to the genus gammacoronavirus, subfamily Coronavirinae. One of the most prominent representatives of gammacoronavirus genus is infectious bronchitis virus (IBV) which is a highly contagious viral pathogen of chickens causing considerable economic losses to the poultry industry. IBVs mostly affect the respiratory, urinary, and reproductive tracts leading to a substantial drop in production. Backyard poultry in the villages usually share their food and water with free flight birds which puts them at serious risk of disease transmission. Furthermore, the poor hygienic measurements which are often used in backyard flocks make them a potential reservoir for diseases that can be transferred to commercial poultry flocks. Live bird markets (LBMs) which receive live poultry to be resold or slaughtered and sold onsite play a significant role in spreading infectious diseases among the different bird species. In the present study, a number of 354 cloacal swab samples were collected from different bird species from LBMs of Gilan province. Subsequently, after RNA extraction, reverse transcription-polymerase chain reaction (RT-PCR) technique was carried out using specific primers of S1 gene to detect coronavirus infectious bronchitis virus. Two samples from backyard chickens were reported to be positive to coronavirus which were named Iran/Backyardchicken96/2017 and Iran/Backyardchicken94/2017. The results of the phylogenetic analysis demonstrated that these two isolates are placed in QX and IS-1494 strains, respectively. On a final note, the obtained results highlighted the role of live birds offered in LBMs in the epidemiology of IBV and the transmission of the virus to the industrial flock.

Avian infectious bronchitis (IB) is a highly contagious viral disease which affects the poultry industry. The virus exists in a wide variety of genotypes, and phylogenetic analysis has been used to classify infectious bronchitis virus (IBV) strains. The object of the study is a molecular characterization of circulating IBV in Afghanistan as a first study. The tracheal tissue specimens from 100 different commercial broiler flocks with respiratory distress in Afghanistan were collected during 2016-2017. After real-time reverse transcriptase-polymerase chain reaction (RRT-PCR), IBV-positive samples were further characterized. A 390 bp hypervariable spike glycoprotein gene segment was amplified using Nested PCR, sequenced, and analyzed. The results of real-time RT-PCR showed that 45/100 of the mentioned flocks were IBV positive. Phylogenetic analysis of all positive samples revealed that IBV strains were clustered into two distinct genotypes: LX4 (GI-19) (9/45) and IS-1494 like (GI-23) (34/45). Also, 2 of the 45 samples remained uncharacterized. It is the first study focusing on the molecular epidemiology of IBV in Afghanistan, extending our understanding of IB in the region. These results showed the high rate of IB infection in Afghanistan broiler farms and confirm the continuing monitoring of IBVs to modify the vaccination program.

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.

Avian infectious bronchitis (IB), caused by a gammacoronavirus, is an OIE-listed (List B) disease and characterized by respiratory and renal involvements, causing high mortality, and economic loss in both layers and broilers. In comparison with other diagnostic methods, real-time polymerase chain reaction (RT-PCR) and conventional RT-PCR are potent, more sensitive and faster techniques for infectious bronchitis virus (IBV) detection. This research was conducted to detect IBV using specific primers of IB in three governorates (Basra, Thi-Qar and Muthana) in the south of Iraq. Tracheal specimens were collected from 46 IB suspected commercial broiler flocks. XCE2 and XCE2- Primers, which amplify all IBV serotypes, were used. Primers MCE1, BCE1 and DCE1 were used to amplify the specific nucleotide sequences of Massachusetts, 793/B and D274 genotypes, respectively. The results of real-time RT-PCR of this study showed that 34 (74.00%) out of 46 infected flocks were positive to IBV. The results of nested PCR showed that 50.00% and 5.89% of positive samples were belonged to genotypes 793/B and Massachusetts, respectively, and the remaining positive (44.11%) were unknown. The results indicate presence of Massachusetts and 793/B IBV strains in commercial broilers in southern Iraq.

Infectious bronchitis (IB) is a very contagious disease caused by a coronavirus (IBV). In chickens, the virus affects the respiratory, reproductive, and urinary systems. This study was carried out to determine the seroprevalence of anti-IBV antibodies in domestic village chickens. Serum samples of 300 domestic village chickens from Esfahan (centeral Iran) were collected and examined for the presence of anti-IBV antibodies by commercial ELISA kits. The results showed that 85.3% of the domestic village chickens had high titers of anti-IBV antibody without any clinical signs. It was concluded that the rate of IBV infection in these chickens is very high that could be a potential hazard for commercial poultry.