Cholesterol supplementation improves growth rates of Histomonas meleagridis in vitro.

Research on the energy metabolism of various protozoan parasites showed the essentiality and benefits of cholesterol in the cultivation of these organisms. However, not much is known about the energy metabolism of Histomonas meleagridis, although such information is of high importance to improve cultivation of the parasite for advancements in diagnostics, research and vaccine development. By supplementing a serum enriched cultivation medium with cholesterol, numbers of parasites could be doubled in comparison to unsupplemented negative controls.

Long-term in vitro cultivation of Histomonas meleagridis coincides with the dominance of a very distinct phenotype of the parasite exhibiting increased tenacity and improved cell yields.

The majority of research on Histomonas meleagridis was performed in the first half of the last century, especially those on morphological aspects. In the present study identical monoxenic settings for cultures of the same H. meleagridis clonal strain in its virulent low passage and attenuated high passage form enabled a comparative analysis of parasite characteristics.