Detection and partial sequence resolvability of some undefined types of human papillomavirus

الملخص EN

Purpose : infection with the high-risk human papillomaviruses (HPVs) has been shown to play an important role in the development of cervical cancer from precancerous lesions.

Screening of clinical specimens for HPV by PCR and genotyping may be challenged by some unidentified types.

This work was designated to detect and type HPV in 30 samples of cervicovaginal cells derived from women with cervical intraepithelial neoplastic grade 1 and further examination of the untamable samples.

Materials and Methods : the consensus primers MY09 / MY11 have been used to amplify 450bp fragment of the viral L1 gene.

Infected samples were typed using dot blot hybridization using a probe mix, which detects more than 40 different genotypes including the major high-risk members.

Genotype-undefined samples were preamplifier using GP5+ / GP6+ primers, sub cloned and sequence analyzed.

Results : the data indicates the prevalence of HPV in 25 (83.3 %) of the 30 samples investigated.

High-risk HPV genotypes were detected in 12 (40 %) samples and multi-infections, with two or more genotypes, were observed in 17 (56.7 %) samples.

Two samples (No.

04 and 19) showed a clear hybridization signal with Pst I cleavage followed by Southern hybridization.

However, they were negative for both MY09 / 11 PCR and dot hybridization.

Re-amplification using GP5+ / GP6+ primers, subcloning and sequence analysis, of these samples revealed that they are harboring HPV genotypes closely related to HPV-54 and to the newly identified HPV-91 with sequence homology 86 % and 96 %, respectively.

Conclusion : the results confirm the importance of HPV genotype determination to monitor the potential development of cervical cancer in patients infected with the high-risk members.

Also, the results indicate the importance of careful examination of type-unidentified samples as a potential source of variants, new types of HPV and for probe enrichment.