Use of Internal Transcribed Spacer Sequence Polymorphisms as a Method for Trichomonas vaginalis Genotyping

Abstract

OBJECTIVE: Trichomonas vaginalis is the most common non-viral, sexually transmitted pathogen with a worldwide distribution. The aim of the present study was to design a new genotyping tool for T. vaginalis isolates using internal transcribed spacer (ITS) sequences. METHODS: First, a total of 20 cryopreserved T. vaginalis isolates were thawed and genomic DNA was isolated from fresh cultures. A polymerase chain reaction (PCR) was performed to amplify the ITS regions and the amplicons were sequenced. These sequences were aligned with others from Genbank and polymorphisms were detected. At last, each ITS sequence was given a different sequence type. RESULTS: More than 99% homology was observed among sequences. Of 20 isolates, five had identical ITS sequence to reference (L29561) defined as ITST1. Moreover, 13 had A58 deletion (ITST10), one had C203T mutation (ITST2), and one had both A58 deletion and C203T mutation (ITST11). ITS typing of T. vaginalis sequences on Genbank revealed a total of 11 ITS types with the predominance of ITST1 (44.4%) globally. CONCLUSIONS: ITS typing seems to be an applicable and useful tool for a better understanding of molecular epidemiology as well as for the dissemination of T. vaginalis clones.