The accurate diagnosis and identification of Leishmania species are crucial for the therapeutic selection and effective treatment of leishmaniasis. This study aims to develop and evaluate the use of high-resolution melting curve analysis (HRM)-PCR for Leishmania species identification causing visceral leishmaniasis (VL), post-kala-azar dermal leishmaniasis (PKDL) and cutaneous leishmaniasis (CL) in the Indian subcontinent. Two multi-copy targets (ITS-1 and 7SL-RNA genes) were selected, and an HRM-PCR assay was established using L. donovani, L. major, and L. tropica standard strain DNA. The assay was applied on 93 clinical samples with confirmed Leishmania infection, including VL (n = 30), PKDL (n = 50), and CL (n = 13) cases. The ITS-1 HRM-PCR assay detected as little as 0.01 pg of template DNA for L. major and up to 0.1 pg for L. donovani and L. tropica. The detection limit for the 7SL-RNA HRM-PCR was 1 pg for L. major and 10 pg for L. donovani and L. tropica. The ITS-1 HRM-PCR identified 68 out of 93 (73.11%) leishmaniasis cases, whereas 7SL-RNA HRM-PCR could only detect 18 out of 93 (19.35%) cases. A significant correlation was observed between the kDNA-based low Ct values and ITS-1 HRM-PCR positivity in the VL (p = 0.007), PKDL (p = 0.0002), and CL (p = 0.03) samples. The ITS-1 HRM-PCR assay could identify Leishmania spp. causing different clinical forms of leishmaniasis in the Indian subcontinent, providing rapid and accurate results that can guide clinical management and treatment decisions.
1 January 2012 in Indian Journal of Dermatology, Venereology and Leprology
Open Access Peer-Reviewed Publication of IADVL IJDVL is an peer-reviewed biomedical periodical of Indian Association of Dermatologists, Venereologists and Leprologists.
Nocardia africana is a recently identified organism and has rarely been reported to cause mycetoma. Here we report the case of a 40-year-old woman who presented with discharging sinuses and nodules for the past 7 years along with few discrete axillary lymph nodes. Cultures and Maldi-TOF MS (Matrix-assisted laser desorption/ionization–time of flight mass spectrometry) method identified the causative organism as Nocardia africana/nova. The organism was acid-fast positive on modified Ziehl-Neelsen stain and Gram's stain revealed branched filamentous beaded gram-positive bacilli, while histopathology showed granulation tissue along with few ill-defined epithelioid cell granulomas, with giant cells. Based on the sensitivity report, the patient was started on tablet moxifloxacin and cotrimoxazole, and has shown considerable improvement at 2.5 months of follow-up.
17 April 2021 in International Journal of Dermatology