Development of a simplified and cost-effective sample preparation method for genotyping of human papillomavirus by next-generation sequencing

High-risk human papillomavirus (HPV) infection is the most common cause of cervical cancer, but low-risk HPV strains can sometimes also be involved. Although HPV genotyping techniques used in clinical diagnosis cannot detect low-risk HPV, next-generation sequencing (NGS) can detect both types. However, DNA library preparation is complicated and expensive. The aim of this study was to develop a simplified, cost-effective sample preparation procedure for HPV genotyping based on next-generation sequencing (NGS). After DNA extraction, a first round of PCR was performed using modified MY09/11 primers specific for the L1 region of the HPV genome, followed by a second round of PCR to add the indexes and adaptors. Then, the DNA libraries were purified and quantified, and high-throughput sequencing was performed using an Illumina MiSeq platform. The sequencing reads were compared with reference sequences for HPV genotyping. The limit of detection for HPV amplification was 100 copies/µl. Analysis of the correlation of pathological cytology with the HPV genotype in individual clinical samples showed that HPV66 was the most common genotype found in the normal stage, whereas HPV16 was the main genotype found in low-grade squamous intraepithelial lesions, high-grade squamous intraepithelial lesions, and cervical cancer. This NGS method can detect and identify several HPV genotypes with 92% accuracy and 100% reproducibility, and it shows potential as a simplified and cost-effective technique for large-scale HPV genotyping in clinical samples.