Recombinant polypeptide of Mycobacterium leprae as a potential tool for serological detection of leprosy

Tp0684, Tp0750, and Tp0792 Recombinant Proteins as Antigens for the Serodiagnosis of Syphilis

The incidence of syphilis has increased alarmingly over the years. Its diagnosis continues to be a challenge, leading to the search for new alternative and effective methods. The objective of this study was to select and evaluate three Treponema pallidum recombinant proteins for potential use in syphilis serodiagnosis. Bioinformatics analysis was performed with three T. pallidum antigens (Tp0684, Tp0750, and Tp0792) to assess their physical, antigenic, and structural characteristics. The antigens were chemically synthesized, recombinant plasmids were expressed in Escherichia coli BL21 Star™ (DE3), and the recombinant proteins were purified by nickel affinity chromatography. The antigenicity of the recombinant proteins was evaluated by western blotting and enzyme-linked immunosorbent assay (ELISA), using the sera from patients with primary and latent syphilis. In silico analysis indicated the antigenic potential once the exposed B cell epitopes were detected in the evaluated proteins. Sera from patients with primary and latent syphilis specifically recognized rTp0684, rTp0750, and rTp0792 recombinant antigens. Moreover, the rTp0684-ELISA receiver operating characteristic (ROC) analysis showed an area under the ROC curve of 0.99, indicating high diagnostic efficacy with 97.62% specificity and 95% sensitivity. In conclusion, rTp0684 showed better potential as an antigen for the development of syphilis serodiagnosis. Thus, bioinformatic analysis can be an important tool to guide the selection of antigens for serological diagnosis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12088-022-01017-w.

Advances in the Diagnosis of Leprosy

Leprosy is a public health issue, and early detection is critical to avert disability. Despite the global attempt to eradicate this disease as a public health problem, it remains an important cause of global neurological disability. India, Brazil and Indonesia share more than 70% of the cases. The reduction of new cases is a priority in the WHO global strategy 2021-2030 which aims to reduce disease transmission in the community by diagnosing cases and identifying subclinical infection. The clinical manifestations of leprosy range from a few to several lesions. The identification remains difficult due to the limited sensitivity of traditional approaches based on bacillary counts of skin smears and histology. To aid in the diagnosis of this disease, molecular biology, and biotechnological technologies have been applied, each with its own set of benefits and downsides despite providing an essential tool to validate the clinical diagnosis of leprosy. Because of this, it is strongly recognized that specific, inexpensive point of care technologies should be developed, particularly to identify asymptomatic M. leprae infections or leprosy nearer to the suspected cases seeking medical attention. Thus, this review will provide an overview of the advancements in leprosy diagnosis over the world. The purpose of this review is to improve our understanding of the outcomes of current tests and technologies used in leprosy diagnosis and to emphasize critical aspects concerning the detection of leprosy bacilli.

Insights into Mycobacterium leprae Proteomics and Biomarkers-An Overview

Although leprosy is curable, the identification of biomarkers for the early diagnosis of leprosy would play a pivotal role in reducing transmission and the overall prevalence of the disease. Leprosy-specific biomarkers for diagnosis, particularly for the paucibacillary disease, are not well defined. Therefore, the identification of new biomarkers for leprosy is one of the prime themes of leprosy research. Studying Mycobacterium leprae, the causative agent of leprosy, at the proteomic level may facilitate the identification, quantification, and characterization of proteins that could be potential diagnostics or targets for drugs and can help in better understanding the pathogenesis. This review aims to shed light on the knowledge gained to understand leprosy or its pathogen employing proteomics and its role in diagnosis.