The efficacy of Triladyl (R) 50% in cryopreservation of low concentration pathogenic trypanosomes

摘要

The efficacy of a bull cryopreservation medium Triladyl (R) in preservation of the various pathogenic trypanosomes was evaluated against the commonly used glycerol ethylenediamine tetraacetic acid (EDTA) saline glucose (ESG). Trypanosoma brucei rhodesiense, T. evansi, T. b. brucei and T. congolense were first propagated in Swiss White mice. At peak of parasitemia, blood was collected from the mice by cardiac puncture and 1 x 10(2) trypanosomes/ml dilution made. This dilution was then divided into 2 equal portions which were cryopreserved in either ESG 10% glycerol or Triladyl (R) 50%. After 1 month of cryopreservation, 2 irradiated mice were intraperitoneally administered with 0.2 ml of the cryopreserved sample and then monitored for parasitemia development. Triladyl-cryopreserved T.evansi and ESG-cryopreserved T. congolense had shorter although not significant prepatent period (PPP) compared to their counterparts in the alternate medium. The peak parasitemia was significantly higher for Triladyl (R)-cryopreserved T. evansi trypanosomes compared to that preserved in ESG. The parasitemia pattern for T. evansi, T. b. brucei and T congolense were characterized by 1 wave while T. b. rhodesiense had 2 waves. For T b. brucei, T b rhodesiense and T. congolense the number of days taken to develop peak parasitemia were shortest for ESG cryopreserved trypanosomes and this was opposite for T. evansi. In conclusion, Triladyl (R) can be used as an alternative cryopreservative medium for trypanosomes and would be the cryopreservative medium of choice for T. evansi trypanosomes based on the PPP, peak parasitaemia and days to peak parasitaemia.