Growth of Trichomonas vaginalis in Basic Media Available in Routine Microbiology Laboratories

Trichomonas vaginalis is a protozoan parasite with unicellular, flagellate, and anaerobic metabolism. It is the second most prevalent pathogen among sexually transmitted agents after viruses. Microscopic examination, culture, and molecular methods are used in the laboratory diagnosis of T. vaginalis. However, in most routine microbiology laboratories, microscopy is preferred instead of culture and molecular methods for T. vaginalis diagnosis because microscopy is cheaper than other methods. This study aimed to produce T. vaginalis in media that can be detected frequently in microbiology laboratories.

In this study, four media, namely, thioglucholate medium (THIO), brain heart infusion medium (BHI), tryptic soy broth medium (TSB), and Brucella broth medium (BRB) were modified and tested. Trypticase-yeast extract-maltose (TYM) medium was used as a reference medium. Each medium tested was enriched with three different serum additives. T. vaginalis trophozoite at a density of 10⁴ parasites/mL was inoculated into each medium and incubated at 37 °C for 10 days. We determined the number of trophozoites using a hemocytometer, and the viability rates were determined using trypan blue.

Trichomonas vaginalis grew extremely well on THIO, BHI, and TSB media but not on BRB media. The time and number of parasites peaked were determined as 100×10⁴ parasites/mL on THIO-ATS and THIO-FCS media on days five and four, respectively, 100×10⁴ parasites/mL on BHI-ATS on day three, 98×10⁴ parasite/mL on BHI-FCS media on day five, 100×10⁴ parasites/mL on TSB-ATS on day four, and 82×10⁴ parasite/mL on TSB-FCS media on day seven. Compared with the reference medium, TYM, T. vaginalis trophozoites survived significantly longer in THIO, BHI, and TSB media.

The rich content of THIO, TSB, and BHI media, which are widely available in routine microbiology laboratories, may allow T. vaginalis growth.