Producción de los antígenos ESAT-6 y CFP-10 de Mycobacterium tuberculosis y evaluación de sus potencialidades en el serodiagnóstico de la tuberculosis activa en una población cubana

Abstract

Mycobacterium tuberculosis (Mtb) is the etiological agent of human tuberculosis (TB), which globally is the
most prevalent disease caused by a single bacterial pathogen. In 2009, worldwide there were an estimated 9,4 million of
new cases and it is estimated that one third of the world population is latently infected with Mtb. Due to to this situation,
some rapid and accurate diagnostic method is required for controlling the morbility and mortality of this disease. In this
work, the genes esat-6 and cfp-10 were cloned in the E. coli plasmid vectors pET3a and pET23d (Promega), respectively.
Both proteins were expressed in the soluble fraction, which facilitated their purification by means of the metal-chelate
affinity chromatography under native conditions with a purity of 90 – 94 %. By the first time, using the methodology of
ELISA, the serodiagnostic potential value of these two proteins was evaluated in a Cuban population. The antibody response
against recombinant CFP-10 and ESAT-6 from the patients group was statistically higher than that from the healthy
BCG-vaccinated individuals. The assays showed a specificity of 97,18 % and low sensitivity of 32 %, value that could be
affected by the treatment of the patients with anti-TB drugs. This parameter might be increased by means of the inclusion
of other immunogenic antigens in the cocktail, considering that antibody responses in TB patients are heterogeneous