Ultramicroelisa para la deteccion de anticuerpos IgM al Mycobacterium leprae utilizando muestras de sangre seca / Ultramicroelisa assay for the detection of IgM antibodies to Mycobacterium leprae using eluates of dried blood spots

En este trabajo se estebelecen las condiciones optimas para la deteccion de anticuerpos IgM al glicolipido fenolitico-I (GF-I) en muestras de sangre en papel de filtro utilizando el UltranicroELISA HANSEN y la tecnologia SUMA. Se estudiaron 30 doantes de sabgre y 58 pacientes leprosos. Para estas dos poblaciones se compararon los resultados de muestras de sangre seca colectadas en papel de filtro SS-2992 con los de suero, y se obtuvo una correlacion de 0.919 para doantes de sangre, 0.969 para pacientes y 0.954 para el total de las dos poblaciones....

Application of ATP assay for in vitro drug screening testing against human derived M. leprae.

In this study, the ATP content of M. leprae exposed to various antimicrobial agents has been measured to evaluate its usefulness in drug sensitivity screening. Purified M. leprae suspensions from human biopsies have been incubated at 30 degrees C in a modified Dubos medium in the presence of different concentrations of various drugs viz., Rifampicin, Ethionamide, Ethambutol, Cycloserine, Dapsone, Clofazimine, Erythromycin and Tetracycline. ATP levels were estimated at 0, 7 days, 14 days of incubation by the procedures modified and standardised at this laboratory. ATP decay was accelerated by ethionamide, rifampicin, clofazimine, dapsone, erythromycin and to a lesser extent by cycloserine, whereas ethambutol and tetracycline did not have any significant effect. The rate of decay depended on the concentrations of these drugs. ATP assay promises to be a useful system for in vitro drug sensitivity screening against M. leprae isolated from patients.

Studies on lipids in mycobacterial cell wall: their important structure and function relating to pathogenicity and their biological activity.

The lipids cord-factor, mycosides and sulpholipids are supposed to be vitally linked with the pathogenecity of mycobacteria. In this paper an attempt has been made to clarify the understanding of the occurrence, organisation and possible interaction of the diverse lipids present in the mycobacterial cell wall and their possible structure and function.

Inflammation induced by a glycolipid fraction from Mycobacterium leprae

1. The inflammatory properties of a glycolipid fraction isolated from human recovered Mycobacterium leprae were investigated. The inflammatory reaction induced in mouse lung by the inoculation of the glycolipid fraction adsorbed to charcoal particles was characterized by a large influx of macrophages at various stages of maturation and of epithelioid cells around the particles. 2. When injected as aqueous emulsion into the footpad of mice, the same fraction evoked a dose-dependent massive influx of mononuclear (MN) cells. The inflammatory reaction reached a peak at 6 days. The minimal effective dose of glycolipid was 0.1 microng. 3. The kinetics of inflammatory cell migration was studied by total and differential counts of leucocytes that migrated to the peritoneal cavity of mice inoculated intraperitoneally with the glycolipid fraction. This fraction initially induced intense polymorphonuclear (PMN) migration, which was later reduced, with a simultaneous increase in MN cells. 4. Adherent peritoneal cells (APC) incubated with glycolipid released one or more soluble factor9s) which induce active PMN and MN cell chemotaxis in vivo as well as in vitro. Thus, the MN cells may be atracted to the site of glycolipid incolulation by factor(s) released through the interaction of macrophages with the glycolipid fraction. 5. the present results demonstrate that a glycolipid containing trehalose and mycolic acid isolated from M. leprae reproduces some aspects of the fundamental lesion of leprosy

Presence of mycobactin-like substance in Mycobacterium leprae.

Chloroform extracts of M. leprae suspensions--crude, partially purified and purified--were prepared by standard methods. Similar extracts were also prepared from the livers of normal armadillos using the same methods that were used to prepare crude and partially purified M. leprae suspensions. The only chloroform extract that supported the growth of M. paratuberculosis was the one prepared from Percoll gradient-purified M. leprae. Other four extracts not only did not support the growth of mycobactin-dependent M. paratuberculosis, but also inhibited the growth of mycobactin-independent strain of M. paratuberculosis. These results suggest the presence of mycobactin-like substance in M. leprae, and also, the presence of other unknown substance(s) in the crude suspensions of armadillo livers that inhibits the growth of M. paratuberculosis.

Absence of mycobactin in Mycobacterium leprae; probably a microbe dependent microorganism implications.

Ferric mycobactins were prepared from Mycobacterium phlei. Mycobacterium avium--intracellulare A and H, isolated respectively from armadillo and human leprosy specimens. Attempts were made to extract mycobactin from host grown M. leprae cells. The crude ferric mycobactin extracts were tested for growth supporting effect on the mycobactin dependent M. paratuberculosis strain ATCC 19698. Mycobactins prepared from M. phlei and the two M. avium--intracellulare strains had growth promoting effect on M. paratuberculosis. The same test organism did not grow in media supplemented with the extract prepared from M. leprae. Results indicate the absence of mycobactin from host grown M. leprae. Since M. leprae cells contain cytochrome c and since mycobactin is essential to growth of all mycobacteria, M. leprae might be considered as a microbe dependent microbe. It is proposed that secondary mycobacteria present in M. leprae infected humans and armadillos might provide mycobactin for in vivo multiplication of M. leprae.