Human mixed infections of Leishmania spp. and Leishmania-Trypanosoma cruzi in a sub Andean Bolivian area: identification by polymerase chain reaction/hybridization and isoenzyme

Parasites belonging to Leishmania braziliensis, Leishmania donovani, Leishmania mexicana complexes and Trypanosoma cruzi (clones 20 and 39) were searched in blood, lesions and strains collected from 28 patients with active cutaneous leishmaniasis and one patient with visceral leishmaniasis. PCR-hybridization with specific probes of Leishmania complexes (L. braziliensis, L. donovani and L. mexicana) and T. cruzi clones was applied to the different DNA samples. Over 29 patients, 8 (27.6 percent) presented a mixed infection Leishmania complex species, 17 (58.6 percent) a mixed infection Leishmania-T. cruzi, and 4 (13.8 percent) a multi Leishmania-T. cruzi infection. Several patients were infected by the two Bolivian major clones 20 and 39 of T. cruzi (44.8 percent). The L. braziliensis complex was more frequently detected in lesions than in blood and a reverse result was observed for L. mexicana complex. The polymerase chain reaction-hybridization design offers new arguments supporting the idea of an underestimated rate of visceral leishmanisis in Bolivia. Parasites were isolated by culture from the blood of two patients and lesions of 10 patients. The UPGMA (unweighted pair-group method with arithmetic averages) dendrogram computed from Jaccard's distances obtained from 11 isoenzyme loci data confirmed the presence of the three Leishmania complexes and undoubtedly identified human infections by L. (V.) braziliensis, L. (L.) chagasi and L. (L.) mexicana species. Additional evidence of parasite mixtures was visualized through mixed isoenzyme profiles, L. (V.) braziliensis-L. (L.) mexicana and Leishmania spp.-T. cruzi.The epidemiological profile in the studied area appeared more complex than currently known. This is the first report of parasitological evidence of Bolivian patients with trypanosomatidae multi infections and consequences on the diseases' control and patient treatments are discussed

Identificación de los clonet 20 y 39 en heces de triatoma infestans por la reacción de la polimerasa en cadena (PCR) / Identification of the clonet 20 and 39 in stools of triatoma infestans by the reaction of the chain polymerase (PCR)

Actualmente, la caracterización genética de las cepas de Trypanosoma cruzi consiste en el análisis isoenzimático o análisis del ADN del genoma e implica el aislamiento y cultivo masivo de cada cepa.

Selección de clones de trypanosoma cruzi por aislamiento y cultivo / Clone selection of Trypanosoma cruzi by isolation and culture

Las cepas que infectan a los huéspedes vectores y mamíferos son poblaciones heterogéneas compuestas de varios clones de T. cruzi; la caracterización genética clásica de las cepas de T. cruzi (electriforesis de isoenzimas, análisis del ADN) requiere cantidades importantes de parásitos y necesita el aislamiento y el cultivo masivo de las cepas.