Fish tank granuloma is caused by

ATYPICAL MYCOBACTERIA * Also known as nontuberculous mycobacteria (mycobacteria other than those causing TB and leprosy) * Found naturally in the environment (water and soil) * Transferred dust, skin injuries, droplets, and occasionally cause oppounistic infections * Ziehl-Neelsen stain; Lowenstein-Jensen culture medium M. marinum (Fish Tank Granuloma):- * Infection follows traumatic inoculation during exposure to an aquatic environment where M. marinum resides as a normal saprophyte (lakes, fish tanks, etc.) * Presents as a slow-growing blue-red papule at the site of inoculation, +- ascending lymphatic sporotrichoid spread; immunosuppressed patients with disseminated lesions Diagnosis:- Tissue culture (grows in 2-4 weeks at 32degC, not 37degC), biopsy suggestive (not pathognomonic) Treatment:- Minocycline, doxycycline, trimethoprim-sulfamethoxazole or clarithromycin for at least 1-2 months after resolution. Ref:- Sima Jain; pg num:-223