Unsupervised Clustering characterizes the CPG dinucleotides distribution of the Andes hantavirus

Abstract

Hantaviruses belong to the family of Bunyaviridae, and small mammals host them. Humans are infected either by inhaling virus-containing aerosols or through contact with animal droppings. Even if rodents host the pathogenic species and humans are dead-end hosts, they get accidentally infected. Andes Orthohantavirusus (ANDV) seems to be the only species with documented person-to-person transmission. Hemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome (HCPS) are both serious syndromes associated with hantavirus infections. For both syndromes, the mortality rate is near 40%. Decades of studies already highlighted the CpG repression in RNA viruses, and both the estimation of the CpG odds ratio and the correlation with their genome polarity were dominant factors to figure out the CpG bias. We conducted the differential analysis of the CpG odds ratio for all the orthohantaviruses on the full segmented genomes (L, M, S). The results suggested the statistical significance of the three groups. The "Small" genomes resulted in the more informative from the CpG odd ratio point of view. We calculated the CpG odds ratio for all the Orthohantaviruses within these segments, and besides, we estimated the correlation coefficient with the relative coding sequences (CDS). Preliminary results firstly confirmed the CpG odds ratio as the lowest among all the nucleotides. Second, highlighted the Andes virus as that whose CpG odds ratio within CDS is highest. The use of these two measures as features for unsupervised clustering algorithms has brought to the identification of four different sub-groups inside of the Orthohantaviridae family. The evidence is that the Andes Hantavirus exhibits a peculiar CpG odds ratio distribution, probably linked to its unique prerogative to pass from human-to-human.