Identificação e caracterização molecular de coronavírus felino (FCoV) em gatos domésticos

Abstract

The feline coronavirus (FCoV) is one of the main viral agents that infects members of the Felidae species, both domestic and wild felines, considered very widespread in the domestic cat population. FCoV is classified into two biotypes, the feline enteric coronavirus (FECV) and the feline infectious peritonitis virus (FIPV), which causes feline infectious peritonitis (FIP), a serious and usually fatal disease. It is described that some alterations in the FCoV genome may be markers that allow the differentiation between FECV and FIPV. Some amino acid substitutions in the spike glycoprotein (S) region, such as the M1058L and S1060A mutations, are postulated as possible markers, although there is still no consensus on the subject. In addition, data on molecular analyzes of FCoV in Brazil are scarce. The present study aimed to detect FCoV in populations of domestic cats with and without clinical signs related to FCoV and/or FIP infection and further analysis regarding amino acid substitutions in the spike glycoprotein (S) region. In the initial part, a literature review is presented regarding the molecular analysis of FCoV, exploring topics regarding viral detection, phylogenetic analysis, and possible markers that differentiate FECV from FIPV. In the second part, research data concerning the identification and occurrence of FCoV in Pelotas - RS/Brazil, in domestic felines are presented. Rectal swabs, necropsy organ samples, blood and/or effusion fluids were collected from 77 cats, totaling 90 samples collected. These samples revealed 26% of positive cats, through reverse transcriptase polymerase chain reaction (RT-PCR), with 11 of them showing enteric signs, 4 showing FIP signs and 5 asymptomatic. Of 9 strains (5 FECV and 4 FIPV) sequenced and confirmed for the M1058L and S1060A mutations, only one FIPV strain contained the M10580L mutation and none contained the previously reported S1060A mutation. The present work presents contributions to the knowledge of the epidemiology of FCoV in the region.