Trichomonas vaginalisandMycoplasma hominis: new tales of two old friends

Abstract

AbstractTrichomonas vaginalisis an anaerobic protist, responsible for the most prevalent non-viral sexually transmitted infection in humans. One of the most intriguing aspects ofT. vaginalispathobiology is the complex relationship with intracellular microbial symbionts: a group of dsRNA viruses belonging to family ofTotiviridae(T. vaginalisvirus), and eubacteria belonging to theMycoplasmagenus, in particularMycoplasma hominis. Both microorganisms seem to strongly influence the lifestyle ofT. vaginalis, suggesting a role of the symbiosis in the high variability of clinical presentation and sequelae during trichomoniasis. In the last few years many aspects of this unique symbiotic relationship have been investigated:M. hominisresides and replicates in the protozoan cell, andT. vaginalisis able to pass the bacterial infection to both mycoplasma-free protozoan isolates and human epithelial cells;M. hominissynergistically upregulates the proinflammatory response of human monocytes toT. vaginalis. Furthermore, the influence ofM. hominisoverT. vaginalismetabolism and physiology has been characterized. The identification of a novel species belonging to the class ofMollicutes(CandidatusMycoplasma girerdii) exclusively associated toT. vaginalisopens new perspectives in the research of the complex series of events taking place in the multifaceted world of the vaginal microbiota, both under normal and pathological conditions.