[Establishment and application of ELISAs based on rLipL32/1-LipL21-OmpL1/2 fusion antigen of Leptospira interrogans].
To establish ELISAs based on rLipL32/1-LipL21-OmpL1/2 fusion antigen of Leptospira interrogans for detecting specific IgG and IgM in serum of patients with leptospirosis.



Microscope agglutination test(MAT) was performed to detect serum specimens from leptospirosis patients and to determine titers of rabbbit antiserum agaist rLipL32/1-LipL21-OmpL1/2 to reference standard strains of L. interrogans. By using rLipL32/1-LipL21-OmpL1/2, rLipL32/1, rLipL21 and rOmpL1/2 as the coated antigens, ELISAs for detecting specific serum IgM and IgG were established. The established ELISAs were applied to MAT-positive serum specimens from 107 patients with leptospirosis.



The results of MAT confirmed that 66% (71/107) of the patients were infected with L.interrogans serogroup Icterohaemorrhagiae, and the rLipL32/1-LipL21-OmpL1/2 antiserum were able to agglutinate all 15 reference standard L.interrogans strains with 1 : 20approximate, equals1 : 160 titers. The positive rates of ELISAs using rLipL32/1-LipL21-OmpL1/2, rLipL32/1, rLipL21 or rOmpL1/2 as the antigen were 89.7%, 75.7%, 85.1% and 79.4% for detecting IgM, respectively, while 99.1%, 99.1%, 94.4% and 86.0% for detecting IgG, respectively. The positive detection rate of rLipL32/1-LipL21-OmpL1/2-IgM-ELISA was higher than those of the other three IgM detection ELISAs (P<0.05). The positive detection rate of rLipL32/1-LipL21-OmpL1/2-IgG-ELISA was higher than that of rOmpL1/2-IgG-ELISA (P<0.05), while there was no significant differnce with that of rLipL21-IgG-ELISA and rLipL32/1-IgG-ELISA (P>0.05).



The ELISAs using rLipL32/1-LipL21-OmpL1/2 as the antigen can be applied as a sensitive,specific and universal serological method for diagnosis of leptospirosis.rLipL32/1-LipL21-OmpL1/2-IgM-ELISA shows a definite value for early diagnosis of leptospirosis compared with the other ELISAs used in this study.
Qiu
Xiao-feng
XF
Department of Microbiology and Parasitology, College of Medicine, Zhejiang University, Hangzhou 310058, China.
Xu
Han-fei
HF
Guo
Zhong-qi
ZQ
Wang
Jiang
J
Yan
Jie
J
D000372:Agglutination Tests; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000235:genetics / Q000378:metabolism*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007921:Leptospira interrogans / Q000235:genetics / Q000276:immunology*; D007922:Leptospirosis / Q000175:diagnosis* / Q000276:immunology; D008074:Lipoproteins / Q000235:genetics / Q000378:metabolism*; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D007074:Immunoglobulin G; D007075:Immunoglobulin M; C545585:LipL21 protein, Leptospira interrogans; C406589:LipL32 protein, Leptospira; D008074:Lipoproteins; D011993:Recombinant Fusion Proteins; C081904:ompL1 protein, Leptospira