Detección de genes asociados a resistencia para isoniacida y rifampicina en cepas de Mycobacterium tuberculosis en Ecuador / Detection of genes associated to resistance for isoniacida and rifampicin in cepas of Mycobacterium tuberculosis in Ecuador

Antecedentes: La incidencia de la multidrogorresistencia (MDR) adquirida a drogas antituberculosas de Mycobacterium tuberculosis en el Ecuador es aproximadamente del 27,83 %. Objetivo: Detectar las mutaciones asociadas con la resistencia a los fármacos en cepas de M. tuberculosis resistentes a fármacos utilizando la PCR-RFLP y PCR en tiempo real. Materiales y métodos: En cepas de M. tuberculosis drogorresistentes (DR) aisladas de muestras provenientes de 18 provincias del Ecuador (2006-2012), se analizaron mutaciones en los genes rpoB y KatG que conducen a la resistencia a rifampicina e isoniazida, respectivamente. EL ADN fue amplificado por Reacción en Cadena de la Polimerasa (PCR), siendo luego analizado por RFLP (40 cepas), qPCR (346 cepas). Resultados: Nuestros resultados demostraron una correlación entre la resistencia fenotípica a rifampicina e isoniazida y las mutaciones encontradas en los genes rpoß (91,6 %) y katG (90,3 %) en cepas ecuatorianas de M. tuberculosis. Conclusiones: Las mutaciones asociadas a la drogorresistencia de aislados del M. tuberculosis en el Ecuador fueron similares a las reportadas en otros países.

Background: The incidence of multidrug-resistance (MDR) acquired in Mycobacterium tuberculosis antituberculosis drugs in Ecuador is approximately 27,83 %. Objective: To detect mutations associated with drug resistance in drug-resistant M. tuberculosis using PCR-RFLP and real-time PCR. Materials and methods: Mutations in rpoB and KatG genes leading to resistance to rifampicin and isoniazid, respectively, were analyzed in isolates of M. tuberculosis (DR) isolated from samples from 18 provinces of Ecuador (2006-2012). The DNA was amplified by Polymerase Chain Reaction (PCR) and then analyzed by RFLP (40 strains), qPCR (346 strains) and Results: Our results demonstrated a correlation between the phenotypic resistance to rifampicin and isoniazid and the mutations found in the rpoß (91, 6 %) and katG (90,3%) genes in Ecuadorian M. tuberculosis strains. Conclusions: Mutations associated with the drug resistance of M. tuberculosis isolates in Ecuador were similar to those reported in other countries.

Epidemiological and immunological aspects of human visceral leishmaniasis on Margarita Island, Venezuela

Sixty-five patients were diagnosed with visceral leishmaniasis (VL) on Margarita Island in the decade from 1990 to1999; 86.2 percent were <= 3 years old. All were leishmanin-negative at diagnosis. Evaluation of 23 cured patients in 1999 revealed that 22/23 had converted to leishmanin-positive; five had persisting antibodies to rK39 antigen, with no clinical evidence of disease. Leishmanin tests were positive in 20.2 percent of 1,643 healthy individuals from 417 households in endemic areas. Of the positive reactors, 39.8 percent were identified in 35 (8.4 percent) of the households, 15 of which had an antecedent case of VL, a serologically positive dog or both. Weak serological activity to rK39 antigen was detected in 3 of 488 human sera from the endemic areas. The presence of micro-foci of intense peri-urban transmission and the apparent absence of other Trypanosomatidae causing human disease offer a unique opportunity for the study of reservoirs, alternative vectors and evaluation of control measures on the Island