Unexpected Presence of Blastocystis Subtype 1-3 DNA in Human Vaginal and Sperm Samples Coinfected with Trichomonas vaginalis

There have been few reports on extra-enteric infections by Blastocystis STs and none have been molecularly identified in samples from human reproductive organs. We report for the first time the identification of 3 different subtypes of Blastocystis (ST1-3) in vaginal and sperm samples, from patients infected with Trichomonas vaginalis. Blastocystis STs were identified by PCR-sequencing and by phylogenetic inferences using 28 vaginal swab samples and 7 sperm samples from patients trichomoniasis. Blastocystis STs were identified in 6 of 28 vaginal swabs (21.4%) and in 3 of 7 sperm samples (42.8%). In both biological samples, STs 1-3 were found; one vaginal sample showed subtype co-infection with ST1 and ST3. High genetic variation was observed in the sequences obtained and no specific clustering in the phylogenetic trees was detected. Most of the haplotypes identified were placed far from the main dispersal centers. Our finding suggested that incorrect cleaning of the genital area or a contamination by combination of anal and vaginal intercourse.

Automated summary

This study reported the first identification of different subtypes of Blastocystis in samples from patients infected with Trichomonas vaginalis, suggesting potential contamination through incorrect cleaning of the genital area or other pathways.