Parasitology Research

, Volume 107, Issue 4, pp 1023–1027 | Cite as

Mycoplasma hominis infection of Trichomonas vaginalis is not associated with metronidazole-resistant trichomoniasis in clinical isolates from the United States

  • Sara E. Butler
  • Peter Augostini
  • W. Evan SecorEmail author
Short Communication


Trichomonas vaginalis is a protozoan parasite that is the cause of the most common non-viral sexually transmitted disease, trichomoniasis. Metronidazole and tinidazole are the only drugs approved for treatment of T. vaginalis infections in the USA. However, drug resistance exists and some patients are allergic to these medications. Furthermore, the exact mechanism of metronidazole resistance remains undefined and current testing methods require several weeks before results are available. Identification of the mechanism of drug resistance may lead to the development of molecular tools to detect drug resistance, and quicker results for clinical treatment. In a recent study, Chinese T. vaginalis isolates that were polymerase chain reaction (PCR) positive for Mycoplasma hominis DNA demonstrated greater in vitro resistance to metronidazole than isolates with no evidence of M. hominis infection. To evaluate this finding in isolates from a distinct epidemiologic setting, we tested 55 T. vaginalis isolates collected from patients in the USA through the Centers for Disease Control and Prevention metronidazole susceptibility testing service. One half of the isolates demonstrated resistance to metronidazole by an in vitro sensitivity assay. Of the metronidazole-resistant T. vaginalis isolates, 18% were PCR positive for M. hominis, as were 22% of the metronidazole-susceptible T. vaginalis isolates (p = 0.746). We also observed no change in metronidazole sensitivity of two infected T. vaginalis isolates after they were cleared of their M. hominis infection by culturing the isolates in antibiotics. Thus, M. hominis infection of USA T. vaginalis isolates did not correlate with in vitro resistance to metronidazole.


Metronidazole Pelvic Inflammatory Disease Tinidazole Trichomoniasis Mycoplasma Hominis 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention.


  1. Berman SM, Harrison HR, Boyce WT, Haffner WJ, Lewis M, Arthur JB (1987) Low birth weight, prematurity, and postpartum endometritis: association with prenatal cervical Mycoplasma hominis and Chlamydia trachomatis infections. J Am Med Assoc 257:1189–1194CrossRefGoogle Scholar
  2. Blanchard A, Yanez A, Dybvig K, Watson HL, Griffiths G, Cassell GH (1993) Evaluation of intraspecies genetic variation within the 16S rRNA gene of Mycoplasma hominis and detection by polymerase chain reaction. J Clin Microbiol 31:1358–1361PubMedGoogle Scholar
  3. Cassell GH, Waites KB (1989) Venereal Mycoplasmal infections. In: Hoeprich PD, Jordan MC (eds) Infectious diseases, a modern treatise of infectious processes. JB Lippincott Company, Philadelphia, pp 632–638Google Scholar
  4. Crowell AL, Sanders-Lewis KA, Secor WE (2003) In vitro metrodnidazole and tinidazole activities against metronidazole-resistant strains of Trichomonas vaginalis. Antimicrob Agents Chemother 47:1407–1409CrossRefPubMedGoogle Scholar
  5. Dessi D, Delogu G, Emonte E, Catania MR, Fiori PL, Rappelli P (2005) Long-term survival and intracellular replication of Mycoplasma hominis in Trichomonas vaginalis cells: potential role of the protozoon in transmitting bacterial infection. Infect Immun 73:1180–1186CrossRefPubMedGoogle Scholar
  6. Dunne RL, Dunn LA, Upcroft P, O'Donoghue PJ, Upcroft JA (2003) Drug resistance in the sexually transmitted protozoan Trichomonas vaginalis. Cell Res 13:239–249CrossRefPubMedGoogle Scholar
  7. Durel P, Couture J, Bassoullet MT (1967) The rapid detection of metronidazole in urine. Br J Vener Dis 43:111–113PubMedGoogle Scholar
  8. Guenther PC, Secor WE, Dezzutti CS (2005) Trichomonas vaginalis-induced epithelial monolayer disruption and human immunodeficiency virus type 1 (HIV-1) replication: implications for sexual transmission of HIV-1. Infect Immun 73:4155–4160CrossRefGoogle Scholar
  9. Jacobs B, Mayaud P, Changalucha J, Todd J, Ka-Gina G, Grosskurth H, Berege ZA (1997) Sexual transmission of hepatitis B in Mwanza, Tanzania. Sex Transm Dis 24:121–126CrossRefPubMedGoogle Scholar
  10. Mayta H, Gilman RH, Calderon MM, Gottlieb A, Soto G, Tuero I, Sanchez S, Vivar A (2000) 18S ribosomal DNA-based PCR for diagnosis of T. vaginalis. J Clin Microbiol 38:2683–2687PubMedGoogle Scholar
  11. Minkoff H, Grunebaum AN, Schwarz RH, Feldman J, Cummings MC, Clark WL, Pringle G, McCormack MW (1984) Risk factors for prematurity and premature rupture of membranes: a prospective study of the vaginal flora in pregnancy. Am J Obstet Gynecol 150:965–972PubMedGoogle Scholar
  12. Petrin D, Delgaty K, Bhatt K, Garber G (1998) Clinical and microbiological aspects of Trichomonas vaginalis. Clin Microbiol 11:300–317Google Scholar
  13. Quon DVK, D’Oliveira CE, Johnson PJ (1992) Reduced transcription of the ferredoxxin gene in metronidazole-resistant Trichomonas vaginalis. Proc Natl Acad Sci USA 89:4402–4406CrossRefPubMedGoogle Scholar
  14. Rappelli P, Addis MF, Carta F, Fiori PL (1998) Mycoplasma hominis parasitism of Trichomonas vaginalis. Lancet 352:1286CrossRefPubMedGoogle Scholar
  15. Rappelli P, Carta F, Delogu G, Addis MF, Dessi D, Cappucinelli P, Fiori PL (2001) Mycoplasma hominis and Trichomonas vaginalis symbiosis: multiplicity of infection and transmissibility of M. hominis to human cells. Arch Microbiol 175:70–74CrossRefPubMedGoogle Scholar
  16. Rasoloson D, Vanácová S, Tomková E, Rázga J, Hrdy I, Tachezý J, Kulda J (2002) Mechanisms of in vitro development of resistance to metronidazole in Trichomonas vaginalis. Microbiol 148:2467–2477Google Scholar
  17. Schmid G, Narcisi E, Mosure D, Secor WE, Higgins J, Moreno H (2001) Prevalence of metronidazole-resistant Trichomonas vaginalis in a gynecology clinic. J Reprod Med 46:545–549PubMedGoogle Scholar
  18. Taylor-Robinson D, Munday PE (1988) Mycoplasmal infection of the female tract and its complications. In: Hare MJ (ed) Genital tract infection in women. Churchill Livingstone, Edinburgh, pp 228–247Google Scholar
  19. Van Belkun A, van der Schee C, van der Meijden WI, Verbrugh H, Sluiters HJ (2001) A clinical study on the association of Trichomonas vaginalis and Mycoplasma hominis infections in women attending a sexually transmitted disease (STD) outpatient clinic. FEMS Immunol Med Microbiol 32:27–32Google Scholar
  20. Vancini RG, Pereira-Neves A, Borojevic R, Benchimol M (2008) Trichomonas vaginalis harboring Mycoplasma hominis increases cytopathogenicity in vitro. Eur J Clin Microbiol Infect Dis 27:259–267CrossRefPubMedGoogle Scholar
  21. Xiao JC, Xie LF, Fang SL, Gao MY, Zhu Y, Song LY, Zhong HM, Lun ZR (2006) Symbiosis of Mycoplasma hominis in Trichomonas vaginalis may link metronidazole resistance in vitro. Parasitol Res 100:123–130CrossRefPubMedGoogle Scholar
  22. Xiao JC, Xie LF, Zhao L, Fang SL, Lun ZR (2007) The presence of Mycoplasma hominis in isolates of Trichomonas vaginalis impacts significantly on DNA fingerprinting results. Parasitol Res 102:613–619CrossRefPubMedGoogle Scholar

Copyright information

© US Government 2010

Authors and Affiliations

  • Sara E. Butler
    • 1
  • Peter Augostini
    • 1
  • W. Evan Secor
    • 1
    Email author
  1. 1.Division of Parasitic Diseases and MalariaCenters for Disease Control and PreventionAtlantaUSA

Personalised recommendations