Cloning and expression of the K26 gene of Leishmania and evaluation of detection of specific antibodies against visceral leishmaniasis in China
To clone and express the K26 gene of Leishmania isolated from three types of visceral leishmaniasis epidemic ar-eas in China and evaluate its effect on detecting specific antibodies against visceral leishmaniasis.The K26 fragments from Leishmania isolated KS-6,SC6 and JIASHI-1 was synthesized and cloned into pET32a vector.The recombinant plasmid pET32a-K26 was transformed into Escherichia coli BL21 strains and induced by isopropyl-β-D-thiogalactopyranoside(IPTG).The expressed recombinant protein was purified by the His-tagged affinity column(Ni-NTA).Serum samples of 110 visceral leishmaniasis patients were used for evaluating the sensitivity by ELISA.Serum samples from patients with malaria,schisto-somiasis japonica,cystechinococcosis,toxoplasmosis,paragon-imiasis,clonorchiosis and 40 healthy people were used for eval-uating the specificity.Detection results of ELISA were compared with that of rK39 strip of American InBios company.Comparation among three K26 antigens were given by x2 test.The sensitivity of the recombinant K26 protein of KS-6,SC6 and JIASHI-5 strains of Leishmania and rK39 strip test to detect the sera of patients with visceral leishmaniasis was 90.00％(99/110),92.73％(102/110),90.91％(100/110)and 93.64％(103/110),respectively.There was no cross reactivity with malaria(10),schistosomiasis japonica(10),cystechinococcosis(10),toxoplasmosis(5),paragonimiasis(5)and clonorchiosis(5),and 40 sera from healthy people were also negative.The specificity was 100.00％.There was no statistical difference in the sensitivity of the recombinant K26 protein of KS-6,SC6 and JIASHI-1 strains of Leishmania and rK39 strip test,x2 values are 0.97,0.07 and 0.57 respectively and the P values are 0.33,0.79 and 0.45,respectively.There was no statis-tical difference in the sensitivity of three K26 antigens(x2=0.53,P=0.97).Conclusion The recombinant K26 antigen has po-tential application value in the diagnosis of visceral leishmaniasis.
万方数据
维普
