Human papillomavirus genotypes and HPV-16 variants distribution among Tunisian women with normal cytology and squamous intraepithelial lesions

Background

Little is known about the epidemiological characteristics of papillomavirus (HPV) infection among North African countries. Herein, we conducted a molecular epidemiological study to investigate prevalence of HPV type and HPV-16 variants among cervical-screened unvaccinated Tunisian women.

Methods

Cross-sectional study was performed on 494 Tunisian women visiting Women’s Healthcare Centers. HPV-DNA detection was carried out on cervical samples using real-time polymerase chain reaction. HPV genotyping and HPV-16 variants were characterized by direct sequencing of L1 viral capsid gene.

Results

The overall HPV prevalence was 34% (95% CI: 30–38%) with significantly higher prevalence among women with squamous intraepithelial lesions (SIL) than those with no intraepithelial lesions (NIL) 84% (95% CI: 76–92%) and 24.5% (95% CI: 20–29%) respectively. The distribution of HPV prevalence according to women’s age shows a U-shaped curve and the highest HPV prevalence rates were observed among the youngest (≤25 years; 51.2%, 95% CI: 37–67%) and the oldest women (>55 years; 41.7%, 95% The HPV-16 prevalence was 32.8% (95% CI: 22–45%) among women with SIL and 9.2% (95% CI: 6–12%) among women with NIL. Whereas, the HPV-18 prevalence was 1.3% (95% CI: 0–5%) among women with SIL and 0.3% (95% CI: 0–1%) among women with NIL. Among HPV-16 positive women, European lineage (E) was identified as the predominant HPV-16 variant (85.7%, 95% CI: 76–95%). The frequency of E variant was lower among SIL than among NIL women (81%, 95% CI: 64–99%, and 88%, 95% CI: 77–100%, respectively). Conversely, the African-2 variant frequency was higher among SIL than among NIL women (18%, 95% CI: 1–36% and 6%, 95% CI: 2–14%, respectively). In multivariate analysis, young age was the only risk factor that is independently associated with HPV infection. Moreover, HPV infection and menopause were both found to be independently associated with SIL and HSIL.

Conclusion

HPV DNA testing should be proposed to young and menopausal Tunisian women. Considering HPV prevalence, only 13% of the Tunisian women could be protected by the bivalent HPV vaccine. These results may be helpful for designing an adapted HPV testing and vaccination program in Tunisia.

Endophyte infection effects on stomatal conductance, osmotic adjustment and drought recovery of tall fescue

Presence of the endophytic; fungus Acremonium coenophialum Morgan-Jones and Gams in tall fescue (Festuca artuidinacea- Sehreb.) enhances host persistence in drought-prone environments. However, the physiological mechanism is not well understood. We investigated the influence of endophyte infection and water deficit on osmotic adjustment, stomatal conductance, tiller survival and leaf elongation rate of genotype GA87-122 and cv. Kentucky-31 (KY31) of tall fescue. Plants were grown in a greenhouse in pots containing fine-silty topsoil (experiment 1) or sand (experiment 2). In expt 1, endophyte-infected (EI) and endophyte-free (EF) isolines of GA87-122 were exposed to two drought preconditioning cycles, after which all pots were re-watered and osmotic adjustment determined. Osmotic adjustment was -0.46 and -0.51 MPa in El leaf blades and tiller bases and -0.29 and -0.13 MPa in EF leaf blades and tiller bases, respectively. In expt 2, EI and EF GA87-122 and KY31 Mere exposed to severe drought after two preconditioning cycles, then re-watered. During the second preconditioning drying cycle of KY31, stomatal conductance tended to be lower in EI than in EF plants, but the difference was significant (P⩽ 0-05) only at two sampling times. Shoot tissues osmotically adjusted 0.17-0.31 MPa more in EI than in EF plants. Tiller survival and leaf elongation rates were higher (P⩽ 0.05) in preconditioned EI than in EF plants. Basal-zone osmotic adjustment was correlated with tiller survival rate in GA87-122 and KY31 (r = 0.87, P⩽ 0.01 for both). Enhanced osmotic adjustment in the meristematic and growing zone might account far improved survival of tillers by facilitating protection of the apical meristem.