Genome characterisation of the first isolate of human enterovirus c99 from an acute flaccid paralysis case in Brazil

BACKGROUND Human enterovirus C99 (HEV-C99) is a member of the species Enterovirus C. Currently, three complete genomes of HEV-C99 were reported in Brazil, all obtained from children with gastroenteritis symptoms. Notwithstanding, no HEV-C99 complete genome associated with AFP cases in Brazil have been analysed so far. OBJECTIVES In light of this, molecular characterisation of an HEV-C99 isolated from a case of acute flaccid paralysis (AFP) in Brazil was carried out. METHODS In 2005, an HEV-C99 strain was isolated from a 2-year-old female child in Santa Catarina State, Brazil, showing classic symptoms of AFP. Stool sample was inoculated into specific cell cultures. Viral RNA was extracted, and polymerase chain reaction (PCR) were performed to amplify the VP1 gene; the sequence was analysed for molecular identification. Subsequently, the complete genome was sequenced and analysed, including a phylogenetic analysis of the VP1 gene. FINDINGS The isolate, denominated HEV-C99/33322/BRA/2005 presented 85.85% identity to other HEV-C99 strains also described in Brazil, subsequently. Besides, the isolate grouped together with HEV-C99 cluster C strains. To our knowledge, this was the first described HEV-C99 isolated from an AFP case in Brazil. MAIN CONCLUSIONS The data generated in this study bolster the role of HEV-C99 as an etiologic agent of AFP. Furthermore, this research enhances our knowledge regarding the HEV-C99 genetic diversity.