Genotyping of Trichomonas vaginalis isolates in Iran by using single stranded conformational polymorphism-PCR technique and internal transcribed spacer regions.

Infection with Trichomonas vaginalis, the causative agent of human urogenital infection, is the most prevalent nonviral sexually transmitted disease worldwide. In spite of the high prevalence and medical importance of trichomoniasis, there is little knowledge about genetic epidemiology and genetic characterisation of this parasite. For this purpose, a Single Stranded Conformation Polymorphism-PCR (SSCP-PCR) typing method was conducted for Iranian T. vaginalis isolates using 5.8s ribosomal gene (rRNA gene) and the flanking internal transcribed spacer (ITS) regions. Nine hundred and fifty vaginal swab samples were examined in which 50 (5.3%) samples were parasitologically positive and used for molecular identification based on SSCP-PCR and nucleotide sequence analyses. Results of the SSCP analysis showed two distinct reproducible banding patterns (I, II) which were confirmed by nucleotide sequence analysis in the ITS1 regions. Frequencies of the SSCP banding patterns I and II were 84% (42/50) and 16% (8/50), respectively. In conclusion, SSCP-PCR analysis provided a reliable and sensitive method for strain genotyping of T. vaginalis based on the ITS1/5.8s/ITS2 region. This finding may help us gain more information about correlation between genetic properties and biological features of this parasite.