Leishmania spp.: cellular levels and synthesis of polyamines during growth cycles

Polyamines were extracted from five different leishmanial strains (Leishmania sp., L. tropica major, L. mexicana, and two L. donovani isolates) and identified as pulrescine, spermidine, and spermine by thin-layer chromatography and mass spectrometry. These sensitive methods were also used to demonstrate the conversion of radioactive putrescine into spermidine and spermine. As in other types of cells, polyamine levels fluctuated during the growth cycle, maximal levels being attained during the logarithmic growth phase. In the five leishmanial strains, which were members of four different serotypes, the spermidine—putrescine ratios also varied, and in two strains of the same serotype, polyamine ratios were practically identical, suggesting that polyamine characteristics might serve as a further criterion for strain identification and classification.