Distinct mutation in the feline coronavirus spike protein cleavage activation site in a cat with feline infectious peritonitis-associated meningoencephalomyelitis

André, Nicole M; Cossic, Brieuc; Davies, Emma; Miller, Andrew D; Whittaker, Gary R

Mutations leading to FIP have also been linked to changes in other areas of the spike gene (position 1058) 19 and in the 3c gene. 20, 21 To compare our findings for the S1/S2 region to other proposed FIP-linked mutations, we performed additional sequencing, which is summarized in Table 3 . All fecal samples, as well as a kidney sample, contained methionine (M) at spike position 1058, indicating that an 'enteric' form of FCoV 22 was present in the cat throughout our study. In contrast, samples from the brain and spinal cord contained leucine (L) at position 1058, indicating an FIP virus. An intact 3c gene was found in feces, with the 3c gene in neural and other tissues truncated and/or deleted depending on the sample tested.