Repeated isolation of nocardia like organisms from multibacillary cases of leprosy

Abstract

Nocardia like organisms were isolated from all the 22 multibacillary cases of leprosy, on minimal media consisting of only mineral salts and supplemented with simple C-sources (e.g., liquid paraffin, tetradecane etc.) and N-sources (e.g. ammonium salts, urea, asparagine, gelatin etc.). Complex organic substances, e.g., xanthine, tyrosine, casein, peptone, meat extract, egg proteins, serum, blood, yeast extract as well as medium 199, did not support the growth of these organisms at all. Paraffin-urea minimal (PUM), paraffin gelatin minimal (PGM) and gelatin minimal medium, as well as the agar slants of these media, selectively allowed good growth of these organisms on which these could be serially propagated continuously, and isolated as pure cultures; these were acid-fast long slender rods which were seen to arise directly from fragmented or unfragmented long, slender hyphae, forming at places mycelial tufts many of which, on ageing, sporulated abundantly. Their acid-fastness was pyridine susceptible and these were DOPA-Oxidase positive; these grew best under reduced 02 tension, at pH 7.0-8.0 and temperature about 28 degrees C. Serologically, these appeared to be sufficiently related to, each other, 2 nocardiae (N. brasiliensis and N. caviae) and some mycobacteria.