Evaluation of combined B cell specific N-terminal immunogenic domains of LipL21 for diagnosis of leptospirosis.
Leptospiral outer membrane protein LipL21 and its truncated N-terminal immunogenic region (I-LipL21) were evaluated for diagnosis of leptospirosis. The complete coding sequence of LipL21 nucleotide sequence was subjected to BCPred and VaxiJen analysis for determination of B cell specific immunogenic epitopes. Epitope1 ACS STD TGQ KDA TTV GDG (1.8837), Epitope2 WGG PPE QRN DGK TPR DTN (0.9483), Epitope3 VKG VGV YEC KAT GSG SDP (1.4077) and Epitope4 NEW ECQ CVI YAK FPG GKD (0.4462) were predicted. LipL21 and N-terminal fragment having B-cell specific epitopes with higher VaxiJen score >0.9 as truncated I-LipL21 were cloned independently in pET15b and expressed in Escherichia coli. IgM ELISA and dot blot assay was performed for sera samples collected from Delhi-NCR for leptospiral whole cell lysate (WCL), recombinant LipL21 and I-LipL21. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were found to be 92.5%, 92.8%, 83.3%, and 97% respectively for recombinant I-LipL21 by IgM-ELISA. 11-14.8% increased sensitivity was observed over LipL21 and WCL. The I-LipL21 dot blot assay showed a further increased sensitivity of 3.8% over the IgM-ELISA. Therefore I-LipL21 may be the ideal candidate protein for diagnosis of leptospirosis.
Medical Microbiology Laboratory, Department of Microbiology, Centre of Excellence in Life Sciences, Bharathidasan University, Tiruchirappalli 620 024, India; Amity Institute of Virology & Immunology (AIVI), Amity University Uttar Pradesh Campus, Sector-125, Noida 201313, India.
Kumari
K
Anita
Amity Institute of Virology & Immunology (AIVI), Amity University Uttar Pradesh Campus, Sector-125, Noida 201313, India.
Mallela Martha
MM
Premlatha
Medical Microbiology Laboratory, Department of Microbiology, Centre of Excellence in Life Sciences, Bharathidasan University, Tiruchirappalli 620 024, India.
Murugesan
M
Kanagavel
Medical Microbiology Laboratory, Department of Microbiology, Centre of Excellence in Life Sciences, Bharathidasan University, Tiruchirappalli 620 024, India.
Charles Solomon
CS
Akino Mercy
Medical Microbiology Laboratory, Department of Microbiology, Centre of Excellence in Life Sciences, Bharathidasan University, Tiruchirappalli 620 024, India.
Veerapandian
V
Raja
Medical Microbiology Laboratory, Department of Microbiology, Centre of Excellence in Life Sciences, Bharathidasan University, Tiruchirappalli 620 024, India.
Santhanam
S
Shanmughapriya
Medical Microbiology Laboratory, Department of Microbiology, Centre of Excellence in Life Sciences, Bharathidasan University, Tiruchirappalli 620 024, India. Electronic address: natarajaseenivasan@rediffmail.com.
Kalimuthusamy
K
Natarajaseenivasan
D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000737:chemistry* / Q000235:genetics; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry* / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D018985:Epitopes, B-Lymphocyte / Q000737:chemistry* / Q000235:genetics; D005260:Female; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood*; D007921:Leptospira interrogans / Q000737:chemistry* / Q000235:genetics; D007922:Leptospirosis / Q000097:blood / Q000175:diagnosis; D008074:Lipoproteins / Q000737:chemistry* / Q000235:genetics; D008297:Male; D000072417:Protein Domains; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D018985:Epitopes, B-Lymphocyte; D007075:Immunoglobulin M; C545585:LipL21 protein, Leptospira interrogans; D008074:Lipoproteins; D011994:Recombinant Proteins
Diagnosis; Dot blot; IgM-ELISA; Leptospirosis; LipL21