CHARACTERIZATION AND CHECK OF IDENTITY OF DIFFERENT STRAINS OF TOXOPLASMA-GONDII BY ENZYMATIC PROFILING

Zymogram analysis of nine strains of Toxoplasma gondii all highly viru lent for mice was performed with the API enzyme research kits(R). The parasite strains had been maintained by continuous intraperitoneal inf ection in mice for many years separately in different laboratories in Europe and were retraced to five isolates (RH, BK, 928, KB, Alt). The API research kits(R) use chromogenic substrates for a semiquantitative detection of 84 enzymes, including the classes aminopeptidases, glyco sidases, esterases, lipases, phosphatases and phosphoamidases. From th e zymograms Manhattan distances were calculated and a hierarchical tre e of the parasite strains was established by complete linkage. All str ains could be easily integrated into two distinct clusters. However, t he correct designation of some strains as direct descendant of a defin ite isolate seems to be questionable. Zymogram analysis is suitable fo r a quick enzymatic characterisation of any mouse virulent Toxoplasma strain and for a simple comparison to defined reference strains. Thus, it allows a rapid detection of any strain confusion during isolation procedures or long term propagation.