Cytochemistry of in vitro cultured Trypanosoma theileri

Abstract

The growth of Trypanosoma theileri Laveran 1902 in continuous blood and nutrient-agar culture at 28 °C was studied to characterize the changes in morphology that occur at different phases of growth, especially those concerned with the increase and demise of the so-called ‘volutin’ granules. Cultured organisms are crithidia though some trypaniforms and leptomonads occur. Live organisms were stained supravitally and also studied by phase-contrast and darkfield microscopy. Fixed organisms were stained in Giemsa as well as examined cytochemically for polysaccharides, hexose sugars, lipids, nucleoproteins, and inorganic ions. When grown in culture at 28 °C, T. theileri accumulates no polysaccharides or acid mucopolysaccharide, though it does contain aggregates of lipid, some of which is phospholipid. The cytoplasm contains ribonucleic acid, and occasional large aggregates of this material can also be seen. A number of large cytoplasmic bodies contains polyphosphate. The results of supravital staining suggests that some, at least, of the cytoplasmic inclusions (or organelles) described are concerned in the uptake and probable digestion and/or detoxification of exogenous materials; and where this material accumulates, as it does when the organism is in an inequable environment, they die. The specific identity of ‘volutin’ is discussed in relation to the findings presented.