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
Ability of a synthetic Aluminium-Magnesium Silicate [AMS] to inhibit activities of canine parvovirus [CPV] was investigated in vitro and in vivo. Five samples of CPV isolated in Nigeria, were each incubated with equal...Ability of a synthetic Aluminium-Magnesium Silicate [AMS] to inhibit activities of canine parvovirus [CPV] was investigated in vitro and in vivo. Five samples of CPV isolated in Nigeria, were each incubated with equal amount of a synthetic AMS on a volume to weight [v/w] basis, for one hour and then centrifuged. Viral titres of the supernatants were tested by the haemagglutination [HA] test and their mean titre compared with mean titre of portions of same viral samples, not incubated with the AMS. Also, five puppies and five adult dogs infected with the parvovirus isolates were treated by dosing each with 400 mg/kg of a drug formulation that has 12% AMS per os for seven days. As control, five puppies and five adult dogs from same class as the experimental dogs were similarly infected but were not treated. Incubating parvovirus with AMS reduced its load from mean HA titre 825.6 ± 261.1 to mean HA, 270.8 ± 132.1 [p < 0.05]. Also treating parvovirus infected dogs with a 12% AMS drug formulation reduced mortality due to the virus from 100% to zero [p < 0.01].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Ability of a synthetic Aluminium-Magnesium Silicate [AMS] to inhibit activities of canine parvovirus [CPV] was investigated in vitro and in vivo. Five samples of CPV isolated in Nigeria, were each incubated with equal amount of a synthetic AMS on a volume to weight [v/w] basis, for one hour and then centrifuged. Viral titres of the supernatants were tested by the haemagglutination [HA] test and their mean titre compared with mean titre of portions of same viral samples, not incubated with the AMS. Also, five puppies and five adult dogs infected with the parvovirus isolates were treated by dosing each with 400 mg/kg of a drug formulation that has 12% AMS per os for seven days. As control, five puppies and five adult dogs from same class as the experimental dogs were similarly infected but were not treated. Incubating parvovirus with AMS reduced its load from mean HA titre 825.6 ± 261.1 to mean HA, 270.8 ± 132.1 [p < 0.05]. Also treating parvovirus infected dogs with a 12% AMS drug formulation reduced mortality due to the virus from 100% to zero [p < 0.01].
