<prompt> Which of the following is known as battey bacillus?Mycobacterium intercellulareMycobacterium tuberculosisMycobacterium lepraeMycobacterium kansasi  <response>: ANSWER: A Mycobacterium intercellulareREF: Principles of Microbiology by Edward Bittar P-158An organism was isolated from patients suffering from pulmonary disease by non tuberculous mycobacterium from a hospital in Battey in Georgia in 1957. It was called the BATTEY bacillus and was later named as the Mycobacterium avium intercellulare.THE ORGANISMMycobacterium avium complex MAC consists of two species: M avium and M intracellulare; because these species are difficult to differentiate, they are also collectively referred to as Mycobacterium avium-intracellulare MAI . MAC is the atypical Mycobacterium most commonly associated with human diseaseFeatures: MAC is primarily a pulmonary pathogen that affects individuals who are immune compromised eg, from AIDS, hairy cell leukemia, immunosuppressive chemotherapy. MAC is the most common cause of infection by nontuberculous mycobacteria NTM in patients with AIDS. M avium is the isolate in more than 95 of patients with AIDS who develop MAC infections. MAC lung disease occurs rarely in immunocompetent hosts. Patients with underlying lung disease or immunosuppression may develop progressive MAC lung disease. M intracellulare is responsible for 40 of such infections in immunocompetent patients.Distribution:MAC is ubiquitous in distribution. It has been isolated from fresh water and salt water worldwide. The common environmental sources of MAC include the following: Aerosolized water Piped hot water systems including household and hospital water suppliesBathroomsHouse dustSoilBirdsFarm animalsCigarette components eg, tobacco, filters, paper Diagnosis: In patients who may have pulmonary infection with Mycobacterium avium complex MAC, diagnostic testing includes acid-fast bacillus AFB staining and culture of sputum specimens. If disseminated MAC DMAC infection is suspected, culture specimens should also include blood and urine.Treatment: In general, MAC infection is treated with 2 or 3 antimicrobials for at least 12 months. Commonly used first-line drugs include macrolides clarithromycin or azithromycin, ethambutol, and rifamycins rifampin, rifabutin. Aminoglycosides, such as streptomycin and amikacin, are also used as additional agents. MAC lymphadenitis in children is treated with surgical excision of the affected lymph node.Also know about runyon classification:RUNYON CLASSIFICATIONThe Runyon classification of nontuberculous mycobacteria based on the rate of growth, production of yellow pigment and whether this pigment was produced in the dark or only after exposure to light.The nontuberculous mycobacteria are divided into four groupsThe first three groups are classified as Slowly growing Mycobacteria.RUNYON CLASSIFICATIONRunyon I organisms photochromogensSlow growing, and produce a yellow-orange pigment when exposed to lightMycobacterium kansasii, Mycobacterium marinum, Mycobacterium asiaticum, and Mycobacterium simiaeRunyon II organisms scotochromogensSlow-growing and produce a yellow-orange pigment regardless of whether they are grown in the dark or the lightMycobacterium Gordonae and Mycobacterium scrofulaceum, Mycobacterium szulgaiRunyon III organisms nonchromogensSlow-growing and never produce pigment, regardless of culture conditionsMycobacterium ahum and Mycobacterium intracellulare together known as the MAI complexRunyon fV organismsRapid growing for mycobacteria colonies in 5 days. They do not produce pigmentMycobacterium fortuitum, Mycobacterium peregrinum, Mycobacterium abscessus, Mycobacterium chelonae, Mycobacterium thermoresistibile 