Newcastle disease (ND) virus is a leading threat to commercial and domestic poultry in Pakistan. The virus infects and constitutes irreversible impairment to the nervous system, damages the respiratory system, and mar...Newcastle disease (ND) virus is a leading threat to commercial and domestic poultry in Pakistan. The virus infects and constitutes irreversible impairment to the nervous system, damages the respiratory system, and marks severe gastrointestinal lesions leading to heavy mortality in short-living birds and substantial losses in layers and breeders. The continuous emergence and evolution of the virus made it inclined to evade the humoral response and indirectly the circumvention of artificial active immunization. Newcastle disease is caused by the orthoavula genus of the paramyxoviridae family and has shown high genetic diversity even in their genotypes while information regarding enzootic trends of the virus is scanty in Pakistan. A total of 40 tracheal samples of NDV were collected from different commercial broiler farms and 11 isolates of NDV were identified. In the current study, we determined the genetic diversity of the Newcastle disease virus based on the partial sequencing of the fusion protein gene available in the NCBI database. Genetic analysis showed that seven isolates belonged to class I genotype VII and four belonged to class II genotype II. Interestingly, two isolates had epidemiological connections with vaccine-like class II genotype II. Our findings, concerning the recent outbreaks of class I genotype VII and class II genotype II of NDV in vaccinated commercial flocks, suggest possible potential partial mutations in the fusion protein gene. Genetic diversity and formation of the new cleavage site in an important neutralizing protein of wild strain are linked with the potency of artificial active immunization and a major cause of vaccine failure.展开更多
Hydro-Pericardium Hepatitis (HPH) is an emerging infectious disease of commercial poultry, caused by different serotypes of Fowl Adeno Virus. The vertical transmission of the virus into the progeny may results in deva...Hydro-Pericardium Hepatitis (HPH) is an emerging infectious disease of commercial poultry, caused by different serotypes of Fowl Adeno Virus. The vertical transmission of the virus into the progeny may results in devastating damage, causing huge economic losses to its farmers. In present study, molecular typing is performed on basis of partially conserved hexon gene sequences, using a unique set of primers having common reverse oligo for simultaneous detection of FAdV1, FAdV-4 and FAdV-11. A total of 14 fowl adeno virus strains were isolated from 100 suspected adeno virus liver samples, collected from different districts in Pakistan, between 2018 and 2019. FASTA’s sequence alignment and phylogenetic analysis revealed that out of the 14, one isolate which belonged to group A showed 27% similarity with FAdV-1, while three isolates showed 99%, 95% & 45% similarity to FAdV-4 (Group C). Whereas, ten isolates showed more than 99% similarity to FAdV-11 (Group D). The serotypes FAdV1, FAdV-4 and FAdV-11 are prevailing in the breeder and broilers. These results hold great importance in rapid, reliable and simultaneous detection of the three FAdV serotypes. Therefore, fowl adeno virus vaccine production for commercial poultry shall be according to the prevalent field serotypes.展开更多
文摘Newcastle disease (ND) virus is a leading threat to commercial and domestic poultry in Pakistan. The virus infects and constitutes irreversible impairment to the nervous system, damages the respiratory system, and marks severe gastrointestinal lesions leading to heavy mortality in short-living birds and substantial losses in layers and breeders. The continuous emergence and evolution of the virus made it inclined to evade the humoral response and indirectly the circumvention of artificial active immunization. Newcastle disease is caused by the orthoavula genus of the paramyxoviridae family and has shown high genetic diversity even in their genotypes while information regarding enzootic trends of the virus is scanty in Pakistan. A total of 40 tracheal samples of NDV were collected from different commercial broiler farms and 11 isolates of NDV were identified. In the current study, we determined the genetic diversity of the Newcastle disease virus based on the partial sequencing of the fusion protein gene available in the NCBI database. Genetic analysis showed that seven isolates belonged to class I genotype VII and four belonged to class II genotype II. Interestingly, two isolates had epidemiological connections with vaccine-like class II genotype II. Our findings, concerning the recent outbreaks of class I genotype VII and class II genotype II of NDV in vaccinated commercial flocks, suggest possible potential partial mutations in the fusion protein gene. Genetic diversity and formation of the new cleavage site in an important neutralizing protein of wild strain are linked with the potency of artificial active immunization and a major cause of vaccine failure.
文摘Hydro-Pericardium Hepatitis (HPH) is an emerging infectious disease of commercial poultry, caused by different serotypes of Fowl Adeno Virus. The vertical transmission of the virus into the progeny may results in devastating damage, causing huge economic losses to its farmers. In present study, molecular typing is performed on basis of partially conserved hexon gene sequences, using a unique set of primers having common reverse oligo for simultaneous detection of FAdV1, FAdV-4 and FAdV-11. A total of 14 fowl adeno virus strains were isolated from 100 suspected adeno virus liver samples, collected from different districts in Pakistan, between 2018 and 2019. FASTA’s sequence alignment and phylogenetic analysis revealed that out of the 14, one isolate which belonged to group A showed 27% similarity with FAdV-1, while three isolates showed 99%, 95% & 45% similarity to FAdV-4 (Group C). Whereas, ten isolates showed more than 99% similarity to FAdV-11 (Group D). The serotypes FAdV1, FAdV-4 and FAdV-11 are prevailing in the breeder and broilers. These results hold great importance in rapid, reliable and simultaneous detection of the three FAdV serotypes. Therefore, fowl adeno virus vaccine production for commercial poultry shall be according to the prevalent field serotypes.
