Molecular detection and phylogenetic analysis of KI polyomavirus and WU polyomavirus in respiratory tract samples...

We aimed to investigate the frequency of KI and WU polyomavirus in respiratory tract samples, the affected groups by these viruses and their clinical characteristics. Although the viruses had been discovered in 2007, their pathogenicity and virulence have not been fully elucidated yet.

We examined 182 nasopharyngeal aspirate/swab samples obtained pediatric patients younger than five years and sent to our laboratory between 2016 and 2019. The viruses were investigated by nested-polymerase chain reaction using primers targeting partial VP1 gene regions. The positive samples were sequenced using Sanger method for verification and compare the genetic distances between partially amplified gene regions.

KIPyV was detected in seven (3.8%) of 182 samples and WUPyV in two (1.1%). Except one KIPyV positive patient, all positive samples belonged to patients <2 years of age. All positive patients were coinfected mainly by rhinovirus and parainfluenza virus 3. Four of the patients positive for KIPyV had haematologic/oncologic diseases or other immunodeficiency conditions. While all of the sequences of KIPyV isolates were 100% similar, sequences of WUPyV isolates differed at 4 nucleotide positions.

According to the results of our study, the frequency of KIPyV and WUPyV infections is low, simultaneous respiratory tract infections caused by other viral or bacterial pathogens, immunosuppression appears to be a predisposing factors for the KIPyV and WUPyV infections. The partially amplified gene regions were highly conserved in both viruses.