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Characterization of field infectious bursal disease viruses in Zambia: evidence of co-circulation of multiple genotypes with predominance of very virulent strains
- Source :
- Avian Pathology. 47:300-313
- Publication Year :
- 2018
- Publisher :
- Informa UK Limited, 2018.
-
Abstract
- Infectious bursal disease (IBD) is a highly contagious, immunosuppressive disease of chickens and causes substantial economic losses to the poultry industry globally. This study investigated the genetic characteristics and pathological lesions induced by IBD viruses (IBDVs) that were associated with 60 suspected outbreaks in chickens during 2015-2016 in Lusaka Province, Zambia. Nucleotide sequences of VP2 hypervariable region (VP2-HVR) (n = 38) and part of VP1 (n = 37) of Zambian IBDVs were phylogenetically analysed. Phylogenetic analysis of the VP2-HVR and VP1 revealed that most viruses (n = 31 of each genome segment) clustered with the very virulent (vv) strains. The rest of the viruses clustered with the classical strains, with two of the viruses being closely related to attenuated vaccine isolates. Two of the viruses that belonged to the vv genotype had a unique amino acid (aa) substitution Q324L whereas one virus had two unique changes, N280S and E300A in the VP2-HVR aa sequence. Although Zambian strains with a vv genotype possessed virulence marker aa within VP1 at 145T, 146D and 147N, two viruses showed unique substitutions, with one virus having 147T while the other had 147H. Pathologically, it was noted that only viruses with a vv genotype appeared to be associated with inducing pathological lesions in non-lymphoid organs (proventriculus and gizzard). Whilst documenting for the first time the presence of classical virulent IBDVs, this study demonstrates the involvement of multiple genotypes, with predominance of vvIBDVs in the epidemiology of IBD in Zambia.
- Subjects :
- 0301 basic medicine
animal structures
Birnaviridae
Genotype
Genotyping Techniques
Zambia
Virulence
Disease
Biology
Infectious bursal disease virus
Disease Outbreaks
Infectious bursal disease
03 medical and health sciences
Food Animals
medicine
Animals
Amino Acid Sequence
Genotyping
Phylogeny
Poultry Diseases
Molecular Epidemiology
General Immunology and Microbiology
Molecular epidemiology
Outbreak
Birnaviridae Infections
medicine.disease
biology.organism_classification
Virology
030104 developmental biology
embryonic structures
Animal Science and Zoology
Chickens
Sequence Alignment
Subjects
Details
- ISSN :
- 14653338 and 03079457
- Volume :
- 47
- Database :
- OpenAIRE
- Journal :
- Avian Pathology
- Accession number :
- edsair.doi.dedup.....cb2dd486efe2505560f545d3b79d2e12