Identification of cutaneous granuloma caused by Mycobacterium marinum using PCR method

Document Type : Research Article


1 Department of microbiology, Science and Research Branch, Islamic Azad University, Tehran, Iran.

2 Department of parasitology, Pasteur Institute, Tehran, Iran.

3 Department of Dermatology, Tehran Medical Sciences University, Tehran, Iran.

4 Department of Biology, Faculty of Basic Sciences, Science and Research Branch, Islamic Azad University,Tehran, Iran

5 Young Researchers and Elites club, Science and Research Branch, Islamic Azad University, Tehran, Iran


Atypical Mycobacterium granulomatous skin infections are often accured by Mycobacterium marinum, M. ulcerans, M. fortuitum, and M. avium colonies. Skin infections probably originate from an environmental source such as contacting with aquatic animals, fish farming and swimming in the pools, and inoculate into skin through skin wounds, scratches, trauma, and surgery. The lesions appear as purple papules, nodules in hands and feet, plaque blisters wart ulcers and markers transmission (sporotrichosis) in the path of lymph nodes. They have granulomatous accumulation with giant cells, and abscess pus appears, and sometimes in the form of ulcerative. Infection is limited to the skin, while in immunosuppressed cases it would be able to infect the whole body. To determine if Mycobacteria were present in granulomatose skin lesion, a total of 58 paraffine embedded tissue blocks were obtained and their DNA was extracted. The polymerase chain reaction (PCR) was used to amplify the HSP-65 gene. PCR amplification demonstrated the presence of Mycobacterium spp.  In 18 blocks (31%).  Among these 18 blocks, 8 (44%) were positive for M. marinum, 3 (17%) for M. ulcerans, 5 (27%) for M. fortuitum and M. chelonae, and 2 (12%) for M. avium. We conclude that Mycobacteria ought to be considered in the treatment of skin granulomas in Iran.