DNA sequence analysis of the triose phosphate isomerase gene from isolates of Giardia lamblia

Objective To confirm the genetic relation between Giardia lamblia (G. lamblia) iso lates from different geographic regions of China and other countries. Methods Genomic DNA were extracted from the trophozoites or cysts of Giardia lamblia .The triose phosphate isomerase (tim) gene was amplified using polymerase chai n reaction (PCR) technique.PCR products were digested with endonuclease and se quenced.The data of sequencing were analyzed with the DNAstar software and com pared with that of the isolates acquired from GenBank. Results Of nine isolates of Giardia lamblia from China (C1, C2, CH2 and CH3), Cambod ia ( CAM), Australia (A1 and A2) and America (BP and CDC), respectively, 3 (A1, A2 an d CAM) fit into Group 1 (WB), 2 (CH2 and CH3)) into Group 2, and 4 (C1, C2, BP a nd CDC) into Group 3 (GS).The results confirmed the genetic relatedness of G .lamblia isolates from all over the world. Conclusion Genotyping isolates of G.Lamblia provides important information for establ ishi ng the phylogenetic relationship or for the epidemiological evaluation of the sp reading of this organism.