title: A sensitive and specific IgM-ELISA for the serological diagnosis of human leptospirosis using a rLipL32/1-LipL21-OmpL1/2 fusion protein.
abstract: OBJECTIVE
  To construct a lipL32/1-lipL21-OmpL1/2 fusion gene and its prokaryotic expression system, and to establish an enzyme-linked immunosorbent assay (ELISA) using the rLipL32/1-LipL21-OmpL1/2 fusion antigen of Leptospira interrogans for sensitive and specific detection of IgM in the serum of patients with leptospirosis.
  
  
  METHODS
  lipL32/1-lipL21-OmpL1/2 fusion genes were constructed using a primer-linking PCR. The target recombinant protein antigens, rLipL32/1, rLipL21, rOmpL1/2 and rLipL32/1-LipL21-OmpL1/2, were expressed and the purified antigens were then immobilized to the surface of microplate wells for ELISA-based detection of IgM in the sera of leptospirosis patients.
  
  
  RESULTS
  Of 493 acute leptospirosis patients, 95.7% and 97.8% were positive by rLipL32/1-LipL21- OmpL1/2-IgM-ELISA using different serum dilutions, which was higher than the rLipL32/1-IgM-ELISA (93.1% and 90.3%), rLipL21-IgM-ELISA (90.3% and 87.0%), and rOmpL1-IgM-ELISA (85.6% and 81.1%) (P<0.01). All IgM-ELISAs tested negative against 56 non-leptospirosis patients with typhoid fever, hemorrhagic fever or dengue fever.
  
  
  CONCLUSIONS
  Trigeminal fusion antigen increases ELISA sensitivity and the rLipL32/1-LipL21-OmpL1/2- IgM-ELISA is a sensitive and specific serological diagnostic method for clinical leptospirosis.
authors.affiliation: Zhejiang Medical College, Hangzhou, China.
authors.forename: Aihua
authors.initials: A
authors.lastname: Sun
authors.forename: Yuan
authors.initials: Y
authors.lastname: Wang
authors.forename: Peng
authors.initials: P
authors.lastname: DU
authors.forename: Shengling
authors.initials: S
authors.lastname: Wu
authors.forename: Jie
authors.initials: J
authors.lastname: Yan
mesh_terms: D000942:Antigens, Bacterial / Q000235:genetics / Q000378:metabolism; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D007075:Immunoglobulin M / Q000276:immunology*; D007922:Leptospirosis / Q000175:diagnosis* / Q000378:metabolism*; D008074:Lipoproteins / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D007075:Immunoglobulin M; C545585:LipL21 protein, Leptospira interrogans; C406589:LipL32 protein, Leptospira; D008074:Lipoproteins; D011993:Recombinant Fusion Proteins; C081904:ompL1 protein, Leptospira