Human papillomavirus type 13 (HPV13) is a low-risk HPV type associated with Multifocal Epithelial Hyperplasia (MEH). It is considered a rare pathology of oral mucosa, more prevalent in certain ethnical groups, such as the Maya from Yucatan in Mexico. As for 2020 only two complete genomes of HPV13 are publicly available in Genbank database (one from Turkey one from the Amazonian). We aimed to obtain the complete genome sequence of HPV13 associated to MEH, obtained from a community in the Mayan area from Mexico. A bank of oral swabs from children with MEH were used. To enrich the sample, a Rolling Cycle Amplification (RCA) method was performed followed by overlapping end-point PCR of 500 bp fragments, Sanger sequencing and assembly. Eight open reading frames (ORFs) were annotated (E1, E2, E4, E5, E6, E7, L1 and L2 genes). When compared with the other two previously reported genomes the identity at nucleotide level is high 98.9% and 99.6%, respectively. The phylogenetic tree shows that Yucatan HPV13 is more closely related to HPV13 obtained from the Amazonian. Most changes identified at amino acid level are substitutions derived from nucleotide variations or SNPs in coding regions. Amino-acid changes were observed in E2 and E1 proteins (n ≥ 8), and in L1, L2, E6 and E5 proteins (n ≤ 5). E7 protein from Yucatan has 100% identity with the reported from Amazonian and differs (94.1% identity) with the one from Turkey due to 3 substitutions and three missing amino acids. In conclusion, the genome from HPV13 (7831 bp, 49 nt missing) associated to MEH in the Mayan area from Yucatan was obtained from stored swabs; this is the first effort in Mexico, the second in Latin America, and the third of the world. More research that contributes to the knowledge of the determinants underlying this neglected pathology are urged.
Read full abstract