Metagenomic sequencing of "HPV-negative" condylomas detects novel putative HPV types.

Condylomas are caused by human papillomavirus (HPV), but may in rare cases be "negative for HPV" by PCR. Metagenomic sequencing can be used for an unbiased assessment of the presence of virus. Ten swab sample pools, each containing four cases of "HPV-negative" condylomas, were subjected to metagenomic sequencing. One pool contained Molluscum contagiosum. Five pools contained HPV, of which three pools contained novel putative HPV-types. The 12 samples in these three pools were sequenced individually. Six of these contained HPV and two contained Molluscum contagiosum. Altogether, 1337 HPV-related reads were detected, representing 23 novel putative Gammapapillomaviruses, 10 established HPV types (genital HPV types 6, 57, 58 and 66, Betapapillomavirus types 5, 105, 124, and Gammapapillomavirus types 50, 130, 150) and two described HPV sequences (KC7 and FA69). Complete genomes of Gammapillomavirus FA69 and SE87 were compiled. Metagenomic sequencing reveals that seemingly "HPV-negative" condylomas contain known and previously unknown HPV types.