Detection of mycobacterial skin infections by polymerase chain reaction (PCR) amplification of deoxyribonucleic acid (DNA) isolated from paraffin-embeded tissue

Atypic mycobacterial granulomatous skin infections are often caused by Mycobacterium marinum, Mycobacterium ulcerans, Mycobacterium fortuitum, Mycobacterium chelonae, and rarely Mycobacterium avium. The lesions appear as papules, nodules in hands, plaque blisters, wart ulcers and markers transmission (sporotrichosis) in the path of lymph glands and lesions; and display a granulomatous accumulation of giant cells. Infection is limited to the skin, and in other cases it could lead to immunosuppression. To determine if mycobacteria were present in granulomatose skin lesion, a total of 58 paraffine tissue blocks were obtained and deoxyribonucleic acid (DNA) isolated the polymerase chain reaction (PCR) that was used to amplify the 16S rRNA gene. PCR amplification demonstrated the presence of Mycobacterium spp. in 18 blocks (31%). Among these 18 blocks, 8 (44%) positive for M. marinum, 33 (17%) for M. ulcerans, 5 isolates (27%) M. fortuitum and M. chelonae, 2 (12%) M. avium. We conclude that mycobacteria ought to be considered in the treatment of skin granulomas in Iran.