title: Comparative assessment of viability of M.leprae by mouse foot-pad and fluorescent staining techniques.
abstract: Morphological characteristics have been used as a parameter to assess the viability of M.leprae in leprosy patients. However, with the advent of the mouse foot-pad technique, viability of M.leprae is determined by growing the bacilli in the mouse foot-pad. In recent years, a fluorescent staining technique using fluorescent diacetate-ethidium bromide (FDA-EB) has been used to assess the viability of cultivable mycobacteria as well as M.leprae. The purpose of this study was to compare the viability of M.leprae by both mouse foot-pad and fluorescent staining techniques. M.leprae strains from both untreated and treated patients as well as mouse passaged strains of M.leprae were used for the comparison. Percentage of green-stained bacilli in the inoculum was compared with that of multiplication of M.leprae in the mouse foot-pad. It was observed that there was no correlation between the estimates of viable M.leprae by fluorescent staining and by mouse foot-pad inoculation. FDA-EB staining appears to reflect only trends as absence of green staining cells had overall general correlation with loss of infectivity to mouse foot-pad but, the converse was not found to be true.
authors.affiliation: CJIL Field Unit (ICMR), Madras.
authors.lastname: Sreevatsa
authors.forename: V M
authors.initials: VM
authors.lastname: Katoch
mesh_terms: D000818:Animals; D001706:Biopsy; D004996:Ethidium; D005456:Fluorescent Dyes; D005528:Foot / Q000382:microbiology; D006801:Humans; D007918:Leprosy / Q000382:microbiology / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D009166:Mycobacterium leprae / Q000502:physiology*; D012867:Skin / Q000382:microbiology
chemical_list: D005456:Fluorescent Dyes; D004996:Ethidium