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Introduction: Fish mycobacteriosis is caused by the non-tuberculous mycobacteria. Infected fish are normally the primary source of infection, although non-tuberculous Mycobacteria can be found in the environment. The present study was designed to investigate the few recently found suspected cases of mycobacteriosis in Iranian ornamental fish tanks. Materials and Methods: Pathological specimens including granolumas from autopsied fish were used to inoculate Lowenstein-Jensen medium. Genomic material was extracted from all acid-fast positive cultures. The mycobacterial identity of bacterial isolates was authenticated using a PCR assessment targeting a 543 bp-long stretch of 16Sr RNA gene. Further more, a PCR assessment targeting a 294 bp-long stretch of heat shock protein hsp65 was performed and the amplicons were sequenced to identify the isolates. Results: Characteristic mycobacterial bacilli were identified both in light and fluorescent microscopy of bacterial culture from all the suspected specimens. PCR-amplification of DNA templates from all isolates successfully resulted in production of the expected products. Existence of Mycobacterium fortuitum was confirmed by comparison analysis of nucleotide sequencing at hsp65 gene. Conclusion: The present work clearly shows mycobacteria are important in pathology of ornamental fish diseases. People who are keeping fish as pet in their homes should be cantioned about the bacterial contamination risks arise from close contact with exotic ornamental species of fish.

An 18-year-old girl was referred to the Department of Oral Medicine with upper lip swelling. She was in good general health and laboratory tests were within the normal range. Histopathologic diagnosis did not reveal the presence of granulomas. This is consistent with the finding that 30% of patients with orofacial granulomatosis do not have granulomas on their biopsies. The patient was treated with intralesional steroids once a week for three weeks. The lesion subsided, but not completely, and recurred partially after ketchup intake. This case report highlights the fact that in every patient with non-odontogenic facial or oral swelling, systemic diseases such as sarcoidosis, Crohn’s disease, tuberculosis, etc. must be excluded. Furthermore, it is not unusual that in patients with orofacial granulomatosis, noncaseating granulomas are absent in the histopathologic finding.

Mendelian susceptibility to mycobacterial diseases (MSMD) is a rare syndrome characterized by predisposition to severe, sometimes lethal, disease caused by otherwise poorly virulent mycobacteria. We report here a boy with a recurrent mycobacterial infection from the age of five months. Immunological analyses revealed an inability to respond to IFN-gamma, subsequent genetic analyses revealed a novel homozygous mutation, r.679G > A in the IFNGR2 gene, resulting in a G227R substitution, that caused IFN-gamma R2 deficiency. This is only the 8th mutation in IFN-gamma R2 known so far. The boy eventually died of hepatic coma due to liver failure at the age of five.