Recombinant LipL32 Protein Developed Using a Synthetic Gene Detects Leptospira-specific Antibodies in Human Serum Samples.

Yuszniahyati Yaakob,Kenneth Francis Rodrigues,Daisy Vanitha John,Timothy William,Fernandes Opook

doi:10.21315/mjms2017.24.5.5

Yuszniahyati Yaakob, Kenneth Francis Rodrigues + Show 3 more

Open Access

https://doi.org/10.21315/mjms2017.24.5.5

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Abstract

Synthetic biology is emerging as a viable alternative for the production of recombinant antigens for diagnostic applications. It offers a safe alternative for the synthesis of antigenic principles derived from organisms that pose a high biological risk. Here, we describe an enzyme-linked immunosorbent assay (ELISA) using the synthetic recombinant LipL32 (rLipL32) protein expressed in Escherichia coli for the detection of Leptospira-specific antibodies in human serum samples. The rLipL32-based ELISA was compared with a microscopic agglutination test (MAT), which is currently used as the gold standard for the diagnosis of leptospirosis. Our results showed that all the MAT-positive serum samples were positive for Leptospira-specific IgG in an ELISA, while 65% (n = 13) of these samples were also positive for Leptospira-specific IgM. In the MAT-negative serum samples, 80% and 55% of the samples were detected as negative by an ELISA for Leptospira-specific IgM and IgG, respectively. An ELISA using the synthetic rLipL32 antigen was able to distinguish Leptospira-specific IgM (sensitivity 65% and specificity 80%) and IgG (sensitivity 100% and specificity 55%) in human serum samples and has the potential to serve as a rapid diagnostic test for leptospirosis.

Highlights

Leptospirosis is a zoonotic disease caused by the pathogen Leptospira interrogans that affects both humans and animals
The constructed recombinant plasmid was introduced into the E. coli BL21 (DE3) host strain, and the transformants were selected in the presence of ampicillin and cultured for expression
The fractions collected after purification by immobilised metal affinity chromatography (IMAC) were analysed by SDS-PAGE (Figure 3)

Summary

Introduction

Leptospirosis is a zoonotic disease caused by the pathogen Leptospira interrogans that affects both humans and animals. The timely diagnosis of leptospirosis remains a challenge, since the organism is not cultivable, and the available diagnostic tests show varying levels of performance [4]. Even though the microscopic agglutination test (MAT) is considered to be the gold standard for the diagnosis of leptospirosis, this assay is not effective for the early detection of the disease. Synthetic biology is emerging as a viable alternative for the production of recombinant antigens for diagnostic applications. It offers a safe alternative for the synthesis of antigenic principles derived from organisms that pose a high biological risk

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