P1891 vaginalis lifecycle revisited

Piotr Kochan1, Agata Pietrzyk2, Alban Vogel*3, Maria Gołębiowska3, Karan Kumar3, Eivind Krågebakk3, Andreas Talgø Lie3, Rebekka Nilsen3, Vilde Strøm3, Michael Zbiegien3, Barbara Papir4, Małgorzata Bulanda5

1Chair of , Department of Bacteriology, and Parasitology, Kraków, Poland, 2Chair of Microbiology, Head of Parasitology Laboratory, Kraków, , 3School of Medicine in English, Jagiellonian University, Parasitology Research Circle, Kraków, Poland, 4Chair of Microbiology , Parasitology Laboratory, Kraków, , 5Jagiellonian University Medical College, Head of the Chair of Microbiology, Kraków, Poland

Background: The World Health Organization (WHO) states there are 1 million new sexually transmitted infections (STI) occurring daily. Among these, with over 140 million infected is ranked 4th, just after HBV with over 250 million infected, HPV with over 290 million and HSV ranked 1st with over 500 million infected. Despite the availability of treatment of this protozoan, it’s still prevalent both in the developing and developed countries, although chlamydial infections are on the rise, currently ranked as 5th by WHO. Trichomoniasis is twice as common as gonorrhea (~78 million), almost 4 times more common than HIV infections (~37 million) and 25 times more common than syphilis (~6 million). Trichomonas infection not only facilitates HIV acquisition due to epithelial damage, but also promotes HIV propagation. We aimed to re-evaluate our current knowledge on the lifecycle of Trichomonas vaginalis, including not only its multiplication, but also possible genetic exchange.

Materials/methods: The study made use of two strains of Trichomonas vaginalis: reference strain ATCC-PRA-92 and the strain from the Chair of Microbiology of Jagiellonian University Medical College. After a 24 hour culture of the parasite in Diamond’s medium at 37ºC the parasite was transferred to a fish-eye microscopic slide and carefully observed over the next hour. The experiment was repeated three fold, with recording of films and pictures under magnification of 100-1000× using light microscopy.

Results: Documented observations of cell divisions differed from the descriptions in the literature listing binary fission. Furthermore the trophozoites became attached to each other in pairs or groups as sort of “plug-and-play” mechanism interconnecting the cells via the axostyle (Fig.1).

Conclusions: In the new millennium medical literature, there are relatively scarce data on division, interconnections and pseudocyst formation in Trichomonas vaginalis and similar parasites, and also few data related to genetic variability or exchange, with some descriptions of in pseudocysts. Is the parasite only using binary fission to multiply? What is the purpose of trophozoites interconnecting with each other? This pilot study shows the need to take another, closer look at T. vaginalis lifecycle using more sophisticated microbiological tools. Figure 1. Interconnecting T.vaginalis cells.