Nontuberculous Mycobacterium in Pulmonary & Extrapulmonary Tuberculosis: Stilla Neglected & Underdiagnosed Pathogen in Developing Countries

Abstract

Non-tuberculous mycobacterium (NTM) has been identified in human pulmonary and extra pulmonary diseases and is of great concern for clinicians and microbiologists because of their increasing global incidence. They are now increasingly recognized as important pathogens in both immunocompromised and immunocompetent population. They should be identified rapidly and should be carefully differentiated as contamination, colonization ordisease. Cultures were made on conventional LJ and LJ with PNB media. Growth was confirmed as AFB (acid fast bacilli) by ZN staining. NTM were identified by growth on LJ with PNB media, colony morphology, rate of growth, pigmentation, catalase activity and confirmed by MPT 64 antigen rapid test (using SD Bioline TB Ag MPT 64 test kit) . Data was analysed statistically using SPSS software. Out of total 500 processed samples (250 pulmonary & 250 extrapulmonary), 12(21.05%) and 7(21.8%) NTM were isolated from pulmonary and extrapulmonary samples respectively. Maximum pulmonary NTM (41.7%) were isolated from > 60 years age of patients in contrast to extrapulmonary NTM isolates which were more in 20-40 years of age group. There was 16.7% previously treated patients in pulmonary while 100% were newly diagnosed patients in extrapulmonary TB cases. This study highlights the importance of early diagnosis and differentiation among Mycobacterium tuberculosisand NTM so that these NTM are not underestimated in routine diagnostic procedures merely as environmental or laboratory contaminants.