Isolation and Identification of a New Duck Adenovirus B2 with Insertion and Deletion Mutations
[Objective]A previously unknown strain of duck adenovirus B2(DAdV B2)was isolated from a ducking of pale liver disease in Fujian and identified for epidemiological reference.[Methods]The virus associated with the disease was detected by PCR and isolated for identification by genome sequencing and a challenge test.[Result]The DAdV B2/BG48 virus infected LMH cells in the duck became swollen like a ballon,and eventually,died and disintegrated.The MDEF cells inoculated with the isolate changed from a spindle-shape to ball-like and clustered together with intercellular spaces in between.Distinctively,BG48 genome had a 3 bp insertion in the pX region,a 33 bp insertion in the ORF19B domain,and 42 bp deletion at the junction between ORF64 and ORF67.A G-base was found on the 133rd spot after the starting code of ORF67 and no truncated mutation in the terminal nor other codes compared with CH-GD-12-2014,or BG27 and BG18 previously identified.In a challenge test,BG48 induced a 50%morbidity and 0 mortality on 2-day-old Muscovy ducks with similar clinical symptoms and pathological changes between the artificially infected and the naturally diseased birds.[Conclusion]A novel DAdV B2 strain,BG48,from a Muscovy duck of pale liver disease was isolated and identified.The virus was uniquely characterized by multiple insertions and deletion mutations in the gene suggesting a potential of causing complex epidemic.
Pale liver diseaseduck adenovirus B2isolation and identificationInsertion and deletionORF67