Feline coronavirus isolates from a part of Brazil: insights into molecular epidemiology and phylogeny inferred from the 7b gene

MYRRHA, Luciana Wanderley; SILVA, Fernanda Miquelitto Figueira; VIDIGAL, Pedro Marcus Pereira; RESENDE, Maurício; BRESSAN, Gustavo Costa; FIETTO, Juliana Lopes Rangel; SANTOS, Marcus Rebouças; SILVA, Laura Morais Nascimento; ASSAO, Viviane Sisdelli; SILVA-JÚNIOR, Abelardo; de ALMEIDA, Márcia Rogéria

In geographic pattern analysis (Table 1) , the topology of the 7b gene phylogenetic tree was supported by significant values of AI and PS, and all countries, with the exception of the United Kingdom (probably due to the lower sample size), showed differentiated subpopulations supported by significant MC values. In virulence pattern analysis (Table 2) , no significant correlations were found by calculation of AI, PS, or MC. Thus, 7b sequences of FCoV isolates are possibly phylogenetically structured according to their geographic origin irrespective of their pathotype as shown by others [1, 2, 4, 17] . These findings contradict the hypothesis of distinct virulent (FIPV) and avirulent (FECV) strains circulating in natural populations of FCoV, proposed by Brown and others [3] . According to this hypothesis, these two viral strains would be expected to be separated into monophyletic clusters in the phylogenetic tree inferred from the 7b gene.