PMC7313338_01
PMC7313338_02
Nasal histopathology. (a) Ethmoturbinates are replaced by extensive inflammation (low magnification). (b) The region of the cribriform plate is obscured by dense sheets of pyogranulomatous inflammation (low magnification). (c) High magnification illustrates the replacement of the cribriform plate by pyogranulomatous inflammation. (d) Feline infectious peritonitis immunohistochemistry reveals extensive immunolabeling in macrophages within the inflammation at the level of the cribriform plate (low magnification)
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PMC7313338_02_10.1177_2055116920930582-fig1.jpg
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Histologic examination revealed a diffuse pyogranulomatous rhinitis that partially obliterated the ethmoturbinates (Figure 1).
Molecular analysis of the spike gene. A 156 base pair region of the feline coronavirus (FCoV) spike gene is shown and represented in single amino acid code, with variant residues and amino acid positions noted. The activation site between the S1 and S2 domains (S1/S2) is indicated and boxed amino acid positions are based on that for FCoV RM spike (Genbank accession # ACT10854.1) as a prototype sequence. Sequences were analyzed using Geneious Prime 2020.05
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PMC7313338_02_10.1177_2055116920930582-fig2.jpg
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Molecular analysis of the viral spike protein showed an amino acid change from an arginine to a serine (R-S) at an essential P1 cleavage activation position at residue 793 (Figure 2).