The aim of this study was to investigate the frequency of the Newcastle disease virus (NDV) infection and its virulence in exotic cage birds over a limited area and time period. A set of 335 samples was collected from 24 different species of exotic unvaccinated cage birds kept in the zoological gardens and bird markets of the Tehran province of Iran during 1.5 years. Except for three pigeons, all of the sampled birds were healthy with no clinical signs of Newcastle disease. NDV was detected in three sick pigeons by haemagglutination assay (HA), haemagglutination inhibition (HI) and reverse transcription-polymerase chain reaction (RT-PCR) tests while two of them were identified as virulent types by RT-PCR. Although the remaining samples were negative by Newcastle-disease-specific HA and HI tests, 35 of them (10%) were identified as positive and 25 (72%) were determined as the velogenic type by RT-PCR test. Five PCR products were sequenced and all were confirmed as NDV but sequences were different from each other and from other sequences from Iran. In total, 14 species (58%) were infected and 10 species were uninfected with the velogenic type without showing any signs. Pigeons are very sensitive to NDV infection and play an important role in its epidemiology. In this study, the PCR test was found to be a more sensitive and powerful method than the HA and HI tests for detection of NDV reservoirs and carrier status in exotic birds. Also, the frequency of infection with the virulent type showed that the exotic birds should probably be considered one of the main causes of recurrent annual epidemics of Newcastle disease in endemic regions.
High mortalities in 17 canary flocks from different regions of Tehran, Iran, were reported. Necropsy and histopathologic examination revealed necrotic hepatitis and overall congestive septicaemia in carcasses. Salmonella enterica was isolated from 34 examined samples, two samples from each flock, including visceral organs of carcasses and droppings of live diseased birds. All isolates were typed as Salmonella enterica serovar Typhimurium by conventional serotyping. Antibiotic resistance profiling using 33 antibiotics and random amplification of polymorphic DNA differentiation by three primers were performed and showed an identical clonal relationship between these isolates and S. Typhimurium isolated from a sample of feedstuffs. Changing the feed ingredients along with antibiotic therapy via the drinking water by enrofloxacin solution controlled the outbreaks, and mortalities ceased. The zoonotic nature of S. Typhimurium and close contact of bird owners with pet birds in the home environment made the case significant in relation to public health.
Background and Aims: Newcastle disease virus (NDV) infection have been established in at least 241species of birds representing 27 of the 50 orders of the class.NDV isolate were obtained from infected ostrich flock during the outbreaks of ND in Iran 2012. The F gene fragment which codes the main functional region of the F protein was obtained by RT-PCR and sequenced. Methods: From the pathotype prediction based on the cleavage site of the fusion protein, this isolate was placed into the velogenic group with the motif 112 RRQKRF 117. Results: Phylogenetic analysis based on a partial F gene sequence showed that the isolates from ostrich cluster together with concurrent isolates from poultry in Iran within the sub genotype VIId, which is the predominant pathogen involved currently in Newcastle disease outbreaks in poultry worldwide.
Conclusion:This study adds to the understanding of the ecology of NDV in ostrich and emphasizes the need for constant surveillance in times of an ongoing and expanding epidemic of NDV. This finding is essential for improving the disease control strategies and development of vaccines for ND.
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