RESEARCH ARTICLE |
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Ahead of Print |
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Molecular identification of Leishmania tropica and L. infantum isolated from cutaneous human leishmaniasis samples in central Morocco
M Echchakery1, C Chicharro2, S Boussaa3, J Nieto2, S Ortega2, E Carrillo2, J Moreno2, A Boumezzough1
1 Ecology and the Environment Laboratory L2E (URAC 32, CNRST ERACNERS 06), Faculty of Sciences Semlalia, Cadi Ayyad University, Marrakesh, Morocco 2 National Center of Microbiology, Institute of Health Carlos III (WHO Collaborating Centre for Leishmaniasis, Parasitology, Spain 3 Ecology and the Environment Laboratory L2E (URAC 32, CNRST ERACNERS 06), Faculty of Sciences Semlalia, Cadi Ayyad University; ISPITS-Higher Institute of Nursing and Technical Health Occupations, Marrakesh, Morocco
Correspondence Address:
S Boussaa, ISPITS-Higher Institute of Nursing and Technical Health Occupations, Marrakesh Morocco
 Source of Support: None, Conflict of Interest: None DOI: 10.4103/0972-9062.308804
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Background & objectives: Cutaneous leishmaniasis (CL) in Marrakesh-Safi region located in the centre-south part of Morocco is a public health problem. This study assessed the efficiency of a microscopic examination method in establishing the diagnosis of CL and PCR for the characterization and identification of the circulating Leishmania strains in different CL foci of the study area.
Methods: A total of 297 smears obtained from cutaneous lesions of suspected patients with CL were stained with May-Grόnwald Giemsa (MGG) for microscopic examination. For each positive smear, genomic DNA was extracted and PCR-analysed, targeting the small subunit ribosomal ribonucleic acid (ssu rRNA) gene to detect Leishmania DNA. Then, the internal transcribed spacer 1 (ITS1) was amplified and sequenced in order to identify the Leishmania species. The sensitivity and specificity of conventional microscopy with ssu rRNA gene were compared by Leishmania nested PCR (LnPCR) and ITS1 gene by ITS-PCR.
Results: A total of 257 smears were positive in the microscopic examination, i.e. the detection rate of amastigotes by optical microscopy was 86.53% (257/297). The LnPCR was found to have a specificity and a sensitivity of 100%, each. Interestingly, the sequencing results showed that 99.61% (256/257) of the isolates had Leishmania tropica and 0.39% (1/257) had L. infantum infection.
Interpretation & conclusion: Though, classical microscopic examination is useful and economical, it is not sensitive enough, especially in endemic regions where several Leishmania species coexist. In such situations, PCR constitutes a complementary method for the identification of the causal species. The results indicate that both the L. tropica (dominant) and L. infantum are the causative agents of CL in the Marrakesh-Safi region. The rate of CL infection is high in Imintanout, and Chichaoua provinces. Hence, early diagnosis and prompt treatment of CL patients is necessary to prevent its extension to neighboring localities. |
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