Studies of quinapyramine-resistance of Trypanosoma brucei evansi in China

In the present article we summarize our studies of antrycide-resistance of Trypanosoma brucei evanst in four aspects in the last recent several years the analysis of quinapyramine-sensitive situation of T b evanst in China biological characteristics of T b evanst population in quinapyramine-resistance and biological materials of quinapyramine-resistance in T b evanst population Firstly the correlative assays of effective dosage of quinapyramine on T b evanst disease between in vivo and in vitro methods showed that their relationship was parabolic with positive correlation On the other hand the IC50 and CD100 values of 12 T b evanst Isolates AHB GDB1 GDB2 HNB JSB1 JSB2 YNB ZJB GDH GXM HBM and XJCA collected from buffaloes horses mules and camels across nine provinces of China were examined using the two methods respectively Among them the nine Isolates AHB GDB1 GDB2 HNB JSB1 JSB2 YNB ZJB and GDH became quinapyramine-sensitive T b evanst Secondly T evanst populations could rapidly obtain antrycide-resistance when they were passed through immunosuppressed mice treated with low doses of the drug But the replication rate of trypanosomes with antrycide-resistance decreases as the level of drug-resistance increases Thirdly the analysis of the HK G6PDH ALAT and ASAT isoenzymes showed that they were not involved in the quinapyramine-resistance of T b evanst But the protein bands of 15 79 kDa and 19 76 kDa might be involved in the antrycide-resistance of T b evanst population At genetic level the gene TbTA1 could be amplified from the T b evanst isolate sensitive to quinapyramine-sensitivity but the T b evanst Isolate with quinapyramine-resistance using not only the RT-PCR technique but also PCR technique We used the SSH (Suppression Subtractive Hybridization) to clone highly or low expressed cDNA fragments caused by production of antrycide-resistance in T b evanst The 5 low and 9 high expressed new cDNA fragments were amplified Among them the 3 low expressed cDNA fragments had the same sequence of 65 amino acids and the 3 high expressed cDNA fragments were located in chromosome VI like T brucei Lastly more work needs to be done in order to elucidate the mechanism of quinapyramine-resistance of T b evanst Crown Copyright (C) 2010 Published by Elsevier B V All rights reserved