Isolation and characterization of avian coronavirus from healthy Eclectus parrots (Eclectus roratus) from Indonesia

Abstract

Background and aim: Avian coronavirus has a wide range of hosts, from chickens and turkeys to wild birds. This virus causes an economically and, possibly, environmentally, important loss in the poultry industry. Therefore, research into the avian coronavirus in various species of birds is required. The Eclectus parrot (Eclectus roratus) is an endemic bird to Indonesia and Northern Australia and often kept as pets. At present, there has been limited information about avian coronavirus infection among birds. This study aimed to determine the presence of and to characterize avian coronavirus isolated from Eclectus parrots in Indonesia.

Materials and methods: Cloacal swab samples were taken from 10 healthy Eclectus parrots (E. roratus). Each isolate was propagated into specific pathogen-free embryonated chicken eggs. The presence of avian coronavirus was determined using three sets of primers targeting the 3' untranslated region (3'-UTR) of avian coronavirus (UTR41+/11-), the N gene of the infectious bronchitis virus (IBVN+/-), and the S1 gene of the IBV (XCE2+/XCE2-). The infectious bronchitis vaccine strain H120 was used as a positive control. Resulting positive bands were sequenced for the S1 gene.

Results: None of the isolates was positive for the 3'-UTR, four isolates were positive for the N gene of infectious bronchitis, and two isolates were positive for the S1 gene of the IBV. However, only one isolate (parrot/Indonesia/BX9/16) was sequenced for the partial S1 gene with primers XCE2+/XCE2-. The partial nucleotide sequence of this isolate showed 100% homology with the IBV GI-13 lineage, specifically with a field isolate of the 4/91 variant 1 Israel and the 4/91 vaccine on the hypervariable region 3 site of the S1 gene.

Conclusion: An IB-like avian coronavirus was isolated from healthy Eclectus parrots. Our results indicate that IBV has a wide range of hosts, which prompt the need to understand the interspecies connection of this virus better.

Keywords: Avian coronavirus; Eclectus parrot; Infectious bronchitis.

Figure-1

Alignment of sample isolate (Parrot/Indonesia/BX9/2016) from the Eclectus parrot with the H120 vaccine positive control (FJ888351.1), the 4/91 vaccine strain (KF377577.1), the Indonesian isolate (MH671341.1 for the 4/91-like isolate and MH671339.1 for the Qx-like isolate), and the 4/91 Israel variant 1 (AF093794.1) strain.

Figure-2

Phylogenetic tree constructed using the maximum likelihood method with 1000 bootstrap replicates. Sample isolate Parrot/Indonesia/BX9/2016 is marked with (•). Positive control H120 vaccine is marked with (■). Indonesian isolates are marked with (▲).