Enoyl-coenzyme A hydratase and antigen 85B of Mycobacterium habana are specifically recognized by antibodies in sera from leprosy patients.

Leprosy is an infectious disease caused by Mycobacterium leprae, which is a noncultivable bacterium. One of the principal goals of leprosy research is to develop serological tests that will allow identification and early treatment of leprosy patients. M. habana is a cultivable nonpathogenic mycobacterium and candidate vaccine for leprosy, and several antigens that cross-react between M. leprae and M. habana have been discovered. The aim of the present study was to extend the identification of cross-reactive antigens by identifying M. habana proteins that reacted by immunoblotting with antibodies in serum samples from leprosy patients but not with antibodies in sera from tuberculosis (TB) patients or healthy donors (HDs). A 28-kDa antigen that specifically reacted with sera from leprosy patients was identified. To further characterize this antigen, protein spots were aligned in two-dimensional polyacrylamide gels and Western blots. Spots cut out from the gels were then analyzed by mass spectrometry. Two proteins were identified: enoyl-coenzyme A hydratase (lipid metabolism; ML2498) and antigen 85B (Ag85B; mycolyltransferase; ML2028). These proteins represent promising candidates for the design of a reliable tool for the serodiagnosis of lepromatous leprosy, which is the most frequent form in Mexico.

Frequency of tuberculous and non-tuberculous mycobacteria in HIV infected patients from Bogota, Colombia.

BACKGROUND: The prevalence of infections by Mycobacterium tuberculosis and non-tuberculous Mycobacterium species in the HIV-infected patient population in Colombia was uncertain despite some pilot studies. We determined the frequency of isolation of Mycobacterium tuberculosis and of non-tuberculous Mycobacterium species in diverse body fluids of HIV-infected patients in Bogota, Colombia. METHODS: Patients who attended the three major HIV/AIDS health care centres in Bogota were prospectively studied over a six month period. A total of 286 patients were enrolled, 20% of them were hospitalized at some point during the study. Sixty four percent (64%) were classified as stage C, 25% as stage B, and 11% as stage A (CDC staging system, 1993). A total of 1,622 clinical samples (mostly paired samples of blood, sputum, stool, and urine) were processed for acid-fast bacilli (AFB) stain and culture. RESULTS: Overall 43 of 1,622 cultures (2.6%) were positive for mycobacteria. Twenty-two sputum samples were positive. Four patients were diagnosed with M. tuberculosis (1.4%). All isolates of M. tuberculosis were sensitive to common anti-tuberculous drugs. M. avium was isolated in thirteen patients (4.5%), but only in three of them the cultures originated from blood. The other isolates were obtained from stool, urine or sputum samples. In three cases, direct AFB smears of blood were positive. Two patients presented simultaneously with M. tuberculosis and M. avium. CONCLUSIONS: Non-tuberculous Mycobacterium infections are frequent in HIV infected patients in Bogota. The diagnostic sensitivity for infection with tuberculous and non-tuberculous mycobacteria can be increased when diverse body fluids are processed from each patient.

[Quality of sputum microscopy in the network of tuberculosis bacteriology laboratories in Colombia]. / Calidad de la baciloscopia de esputo en la red de laboratorios de bacteriología de tuberculosis en Colombia.

The objective of this study was to evaluate the technical quality of sputum microscopy carried out for diagnostic purposes in the Network of Tuberculosis Bacteriology Laboratories in Colombia. The National Central Reference Laboratory received 6,529 slides for reexamination from the network of 513 sectional, regional, and local laboratories, which contributed 33.2%, 27.6%, and 39.2%, respectively, of the slides. These included all the positive (3,283) and negative (3,246) smears processed during a 4-month period. The reexamination was carried out by six laboratory workers who did not know the origin of the slides or the original diagnosis. When qualitative problems were detected, a second reexamination was done, which significantly increased the percentage of agreement for both the positive results (93.9%) and the negative (98.7%). Overall, the level of agreement was 96.3%. A significant correlation was found (P < 0.05) between good slide preparation and staining and agreement in the readings, as well as between thin smears, presence of fuchsin precipitates, and deficient coloration and conflicting readings (P < 0.05). The highest percentages of agreement were associated with laboratories that performed the largest number of sputum examinations each month (96.5%), and with readings done by experienced, university-trained bacteriologists (96.6%). It is concluded that indirect technical supervision and ongoing training of laboratory personnel are important determinants of the impact of the tuberculosis control program.

Calidad de la baciloscopia de esputo en la red de laboratorios de bacteriología de tuberculosis en Colombia / Quality of sputum microscopy in the network of tuberculosis bacteriology laboratories in Colombia

El objetivo fue evaluar la calidad técnica de la baciloscopia de esputo realizada con fines diagnósticos en la Red de Laboratorios de Bacteriología de la tuberculosis en Colombia. En el Laboratorio Central Nacional de Referencia se recibieron para relectura 6 529 láminas provenientes de la red de 513 laboratorios seccionales, regionales y locales, los cuales contribuyeron 33,2, 27,6 y 39,2 por ciento de las láminas, respectivamente. Estas representaron todas las baciloscopias positivas (3 283) y la siguiente negativa (3 246) procesadas durante un período de cuatro meses. La relectura estuvo a cargo de seis lectores que desconocían la procedencia de las láminas y el diagnóstico original. Cuando se detectaron discordancias cualitativas, se hizo una segunda relectura que aumentó significativamente las concordancias, tanto de los resultados positivos ((3,9 por ciento) como de los negativos (98,7 por ciento), con una concordancia total de 96,3 por ciento. Se hallo una correlación significativa (P0,05) entre buen extendido y buena coloración y las lecturas concordantes, así como entre extendidos delgados, presencia de precipitados de fucsina y decoloración deficiente y las lecturas discordantes (P0,05). Los porfcentajes de concordancia más altos se relacionaron con los laboratorios que realizan mensualmente el mayor número de baciloscopias (96,5 por ciento), y con las lecturas por bacteriólogos universitarios experimentados (96,6 por ciento). Se concluyed que la supervisión técnica indirecta y la continua capacitación del personal de laboratorio son factores determinantes del impacto del Programa de Control de la Tuberculosis

Calidad de la baciloscopia de esputo en la red de laboratorios de bacteriología de tuberculosis en Colombia / Quality of sputum microscopy in the network of tuberculosis bacteriology laboratories in Colombia

El objetivo fue evaluar la calidad técnica de la baciloscopia de esputo realizada con fines diagnósticos en la Red de Laboratorios de Bacteriología de la tuberculosis en Colombia. En el Laboratorio Central Nacional de Referencia se recibieron para relectura 6 529 láminas provenientes de la red de 513 laboratorios seccionales, regionales y locales, los cuales contribuyeron 33,2, 27,6 y 39,2 por ciento de las láminas, respectivamente. Estas representaron todas las baciloscopias positivas (3 283) y la siguiente negativa (3 246) procesadas durante un período de cuatro meses. La relectura estuvo a cargo de seis lectores que desconocían la procedencia de las láminas y el diagnóstico original. Cuando se detectaron discordancias cualitativas, se hizo una segunda relectura que aumentó significativamente las concordancias, tanto de los resultados positivos ((3,9 por ciento) como de los negativos (98,7 por ciento), con una concordancia total de 96,3 por ciento. Se hallo una correlación significativa (P0,05) entre buen extendido y buena coloración y las lecturas concordantes, así como entre extendidos delgados, presencia de precipitados de fucsina y decoloración deficiente y las lecturas discordantes (P0,05). Los porfcentajes de concordancia más altos se relacionaron con los laboratorios que realizan mensualmente el mayor número de baciloscopias (96,5 por ciento), y con las lecturas por bacteriólogos universitarios experimentados (96,6 por ciento). Se concluyed que la supervisión técnica indirecta y la continua capacitación del personal de laboratorio son factores determinantes del impacto del Programa de Control de la Tuberculosis