ITS1 PCR-RFLP Diagnosis and Characterization ofLeishmaniain Clinical Samples and Strains from Cases of Human Cutaneous Leishmaniasis in States of the Mexican Southeast

Abstract

American cutaneous leishmaniasis includes a spectrum of clinical forms localized cutaneous, diffuse cutaneous, and mucocutaneous leishmaniasis which can be caused by different strains of Leishmania belonging to the L. mexicana or L. braziliensis complexes which may coexist in the same endemic area. We evaluated the PCR-RFLP assay of the ITS1 genes for direct identification of Leishmania species in 163 clinical samples and 21 Mexican isolates of Leishmania. In relation to the Mexican isolates of Leishmania 52% displayed a pattern similar to the L. (L.) mexicana, 5% showed a mixed pattern compatible with L. (L.) mexicana and L. (V.) braziliensis, eight with L. (L.) amazonensis and L. (L.) mexicana, and one to L. (V.) braziliensis. Most of the clinical samples, 109/116 (94%), gave a pattern similar to that of the L. mexicana, two clinical samples gave similar patterns to that of Leishmania braziliensis, and 5 samples gave patterns that suggest a coinfection of L. (L.) mexicana and L. (V.) braziliensis or L. (L.) mexicana and L. (L.) amazonensis. The ITS1 PCR-RFLP assay is a multipurpose tool for diagnosis of Leishmania from clinical samples and enables determination of the infecting species of New World Leishmania in the field in relatively short time and low cost.

Survey of Cutaneous Leishmaniasis in Mexico: Leishmania Species, Clinical Expressions and Risk Factors

“…The isolate PCR products hybridized with probe 9.2 specific for the L. mexicana complex. Their DNA was also analyzed using ITS1 PCR-RFLP, and we confirmed the presence of both DNA of L. (L.) amazonensis and L. (L.) mexicana in the same isolate ( Table 2) [12,17].…”

“…Furthermore, we found DCL caused by a mix infection with strains of L. (L.) amazonensis and L. (L.) mexicana [12], both belonging to the L. mexicana complex. VL can be caused by L. (L.) chagasi and in immunocompromised patients by L. (L.) mexicana.…”

“…Biopsies, clinical samples, and isolates from LCL patients from several districts of Campeche state, mainly from Calakmul, were PCR amplified with specific primers for kDNA of L. braziliensis and L. mexicana complex members and primers specific for Mexican strains of L. mexicana [19] and also were analyzed by ITS1 PCR-RFLP [12]. We detected in Northern Calakmul 43% of cases infected with L. mexicana, 25% of cases with L. braziliensis complex members, 62% of mixed infection of Mx L. mexicana + L. (L.) mexicana, and 25% of cases infected with L. braziliensis complex + L. (L.) mexicana.…”

“…The target was minicircle kinetoplast DNA (kDNA) using specific primers or probes with the PCR and Southern or dot blotting [11] and PCR-RFLP of the internal transcribed spacer 1 (ITS1) [10,12].…”

“…Amplification conditions were as described [12]. PCR products were digested with HaeIII enzyme, Table 1.…”