Isolation, full sequence analysis, and in situ hybridization of pigeon paramyxovirus-1 genotype VI.2.1.1.2.2 from oriental turtle doves (Streptopelia orientalis)

Pigeon paramyxovirus-1 (PPMV-1), a genetic variant of avian paramyxovirus-1 (APMV-1), has been identified in Columbiformes and is the primary cause of diseases in captive and free-ranging pigeons. However, it has also been reported that PPMV-1 can infect chickens naturally and experimentally, thus posing a potential threat to the poultry industry. This study investigated a lethal outbreak of paramyxovirus infection that occurred among 16 oriental turtle doves (Streptopelia orientalis) in a walk-in aviary at a zoo from March to April 2021. Necropsies were performed, and histopathological findings revealed mild to moderate lymphoplasmacytic infiltration in several organs, such as the pancreas, liver, kidneys, and lungs. Reverse transcription polymerase chain reaction (RT-PCR) using formalin-fixed paraffin-embedded tissue blocks, virus isolation from fresh tissue, and in situ hybridization against the fusion (F) protein confirmed the diagnosis for PPMV-1 infection. The isolated strain NTU/C239/21 was fully sequenced by next-generation sequencing, and the results of phylogenetic analyses revealed that the F protein of NTU/C239/21 shared 98.8% nucleotide sequence identity with Pigeon/Taiwan/AHRI121/2017, which was isolated from a feral pigeon in Taiwan. The present study is the first to identify PPMV-1 infection in Streptopelia orientalis and suggests that Streptopelia orientalis may also play an important role in spreading the infection, similar to pigeons in APMV-1 spreading.