Field strain feline coronaviruses with small deletions in ORF7b associated with both enteric infection and feline infectious peritonitis.
Feline coronavirus (FCoV) varies greatly from causing subclinical or mild enteric infections to fatal feline infectious peritonitis (FIP). The open reading frame (ORF) 7b of FCoV has been speculated to play a determining role in virulence as deletions were found to be associated with avirulent viruses. To further clarify the correlation between this gene and FIP, clinical samples from 20 cats that had succumbed to wet-type FIP and 20 clinically healthy FCoV-infected cats were analysed. The ORF7b from the peritoneal/pleural effusions of FIP cats and from the rectal swabs of healthy cats was amplified. Of the 40 FCoVs analysed, 32 were found to have an intact 7b gene whereas eight showed deletions of either three or 12 nucleotides. Surprisingly, among the eight viruses with deletions, three were from FIP diseased cats. These results show that deletions in the ORF7b gene are not constrained to low pathogenicity/enteric biotypes but also associated with pathogenicity/FIP biotypes of FCoV.
Lin
Chao-Nan
CN
Department of Veterinary Medicine, Graduate Institute of Veterinary Medicine, National Taiwan University, Taiwan.
Su
Bi-Ling
BL
Huang
Hui-Pi
HP
Lee
Jih-Jong
JJ
Hsieh
Min-Wei
MW
Chueh
Ling-Ling
LL
D000818:Animals; D002415:Cats; D016765:Coronavirus, Feline / Q000235:genetics* / Q000472:pathogenicity; D016766:Feline Infectious Peritonitis / Q000821:virology*; D005260:Female; D014644:Genetic Variation; D016679:Genome, Viral; D008297:Male; D008969:Molecular Sequence Data; D012367:RNA, Viral / Q000235:genetics*; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics
D012367:RNA, Viral; D012324:RNA-Dependent RNA Polymerase