Isolation, pcr based identification, and sensitivity pattern of environmental mycobacteria from leprosy and tuberculosis patients

Abstract

We have isolated and identified the biotype of environmental mycobacteria from the expectorate of leprosy patients, their contacts, their drinking water supply and also from the sputa samples of tuberculosis patients. 78% of the isolates from lepromatous leprosy patients and their contacts were Mycobacterium fortuitum- chelonae complex (MFC), 9% Mycobacterium avium complex (MAC), 9% Mycobacterium scrofulaceum and 4% were Mycobacterium smegmatis. Among the isolates from tuberculosis patients 63% belonged to M. fortuitum- chelonae complex, 19% to M. avium complex, 12% to Mycobacterium Kansasiiand 6% to M. smegmatis. All the isolates were multi-drug resistant when tested for sensitivity total of 21 drugs. The Mycobacterium fortuitum-chelonae complex organisms from leprosy contacts were more sensitive to rifampicin than those isolated from lepromatous leprosy and tuberculosis patients. Among 23 isolates from leprosy patients one isolate was resistant to 20 drugs, one isolate to 17 drugs and another isolate was resistant to 13 drugs. Among the 18 isolates from drinking water supply six showed resistance to more than 12 drugs. Polymerase Chain Reaction (PCR) and subsequent hybridisation with specific probes confirmed all the isolated strains as non-tuberculous mycobacteria (Using genus primers and probe sensitivity 100%) and none as M. tuberculosis, suggesting that PCR could be used to rapidly identify mycobacteria at the genus level and to rule out tuberculosis in leprosy patients at an early stage to decide on appropriate course of therapy.