Prevalence of double-stranded RNA virus in Trichomonas vaginalis isolated in Italy and association with the symbiont Mycoplasma hominis

  • Valentina Margarita
  • Alessandra Marongiu
  • Nicia Diaz
  • Daniele Dessì
  • Pier Luigi FioriEmail author
  • Paola Rappelli
Protozoology - Short Communication


The flagellated protozoon Trichomonas vaginalis, responsible for trichomoniasis, can establish a symbiotic relationship with the bacterium Mycoplasma hominis and can harbor double-stranded RNA Trichomonasvirus (TVV). In this study, we investigated by real-time PCR the prevalence of the four TVVs and of M. hominis among 48 T. vaginalis strains isolated in Italy, and we evaluated a possible association with metronidazole resistance. Fifty percent of the analyzed trichomonad strains tested positive for at least one TVV T. vaginalis, with TVV2 being the most prevalent, followed by TVV1 and TVV3. Two T. vaginalis strains were infected by TVV4, detected in Europe for the first time. Interestingly, we found more than one TVV species in 75% of positive trichomonad strains. M. hominis was present in 81.25% of T. vaginalis isolates tested, and no statistically significant association was observed with the infection by any TVV. Metronidazole sensitivity of T. vaginalis isolates was evaluated in vitro, and no correlation was observed between minimal lethal concentration and the presence of TVVs. This is the first report on TVV infection of T. vaginalis in Italy. Even if no association of TVV positive isolates with the presence of the symbiont M. hominis or with metronidazole resistance was observed, further studies are needed to shed light on the effective role of infecting microorganisms on the pathophysiology of T. vaginalis.


Trichomonas vaginalis Double-stranded RNA virus Mycoplasma hominis Metronidazole resistance Symbiosis Real-time PCR 



We sincerely thank Dr. Giuseppe Delogu for excellent technical assistance

Funding information

This work was supported by Ministero dell’Istruzione, dell’Università e della Ricerca, PRIN 2017 grant number 2017SFBFER_004.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Department of Biomedical SciencesUniversity of SassariSassariItaly
  2. 2.Mediterranean Center for Disease Control (MCDC)Università degli Studi di SassariSassariItaly

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