Fish tank granuloma is caused by:

Ans: B (M. Marinum) M. MARINUM Harrison 17th/1031M. marinum is widely distributed in water and causes chronic cutaneous infection when an open cutaneous lesion is exposed to a colonized water source. Most infections are due to hand or upper-extremity exposure to fish tanks, and some are due to shellfish or marine exposures.Swimming pools are no longer a common source of infection because of current chlorination standards. M marinum grows optimally at 30degC--a lower temperature than is optimal for most pathogenic mycobacteria. After a median incubation period of 21 days (>30 days in 35% of cases), a granulomatous or ulcerating skin lesion develops at the site of entry, with subsequent sporotrichoid spread in many cases.M. KANSASII Harrison 17th/1030It is the most pathogenic nontuberculous mycobacterial species affecting the lung, and the clinical features of Af. kansasii disease resemble those of tuberculosis. Most cases include cough and sputum production; 30% include frank hemoptysis.Systemic signs and symptoms, including fever, nightsweats, and weight loss, are reported by as many as 50% of patients.Table (Ananthanaran 8th/362) Atypical mycobacteria associated with human diseaseSpeciesNatural habitatType of infectionM. africanumAnimals, soilPulmonary-M. asiacticumPrimatesPulmonaryM. avium intracellulareSoil, sea water animatsPulmonary, systemic, gastrointestinal, lymphadenitisM. cheionaeSoil, sea water, animalsPorcine heart valves, surgical wound, pulmonaryM. cheionae, ssSoil, sea water animalsCutaneous, surgical abscess wound - pulmonary-systemicM. fallaxWater, soilPulmonaryM. fortuitumWater, soil animalsPulmonary, surgical wound cutaneous, systemic, bone and jointM haemophiium M. KansasiiUnknown Water, animalsCutaneous, subcutaneousPulmonary, systemic, skin joints, lymph nodesM. malmoenseUnknownPulmonaryM. marinumAquarium water, fishCutaneous (swimming pool granuloma), jointsM. scrofulaceumSoil, water, fomitesLymphadenitis (usually cervica); pulmonary disseminatedM. schimoideiUnknownPulmonary'M. simiaePrimates, waterPulmonaryM. szulgaiUnknownPulmonary, lymphadenitis, cutaneous, subcutaneous bursitisM. ulceransUnknownCutaneousM. xenopiSoil, waterPulmonary, epididymitis