Mycobacterium elephantis, a bacterium of the family Mycobacteriaceae, was discovered and isolated from a deceased elephant near India and may be linked to respiratory dysfunction. Organisms in the genus Mycobacterium are known to be aerobic and non-motile. Organisms within Mycobacterium belong to either the rapid growing group (Organismal growth under seven days) or the slow growing group. M. elephantis is classified as a rapid grower and relates most closely to Mycobacterium confluentis and Mycobacterium phlei. Origin Shojaei et al. discovered this bacterial species from a lung of a deceased elephant due to chronic respiratory disease in Sri Lanka, an island off the south end of India in the year 2000. A strain of the organism, 484t, was isolated on Lõwenstein-Jensen medium by these researchers. L-J medium, Columbia blood, MacConkey agar, Middlebrook 7H10 agar, and 5% sodium chloride agar served as cultures for M. elephantis at varying temperatures for 3 to 10 days. No growth occurred on the 5% NaCl agar. This organism was found to be positive in a nitrate reduction test and negative in the aryl sulfatase test that were performed on this strain. Biology and biochemistry Ecology M. elephantis growth has been studied to find its preferred environmental factors. It is known to grow in the bronchial area of mammals, which rests at a pH of 5.5. The organism is host associated with mammals, suggested by the first isolation in the lung abscess of an elephant diagnosed with chronic respiratory disease in Sri Lanka. Most strains of this organism are found in sputum from the respiratory tract with strains found rarely in the lymph nodes. Morphology Through 16S rRNA gene sequencing, this Gram positive bacteria correlates to the Genus Mycobacterium; but high-performance liquid chromatography and PCR-restriction enzyme pattern analysis identifies a new species. Its phenotypic characteristics are in close relationship to M. flavescens. The phenotype shows a coccobacillary acid-fast organism when cultured in 12B broth and Löwenstein-Jensen solid medium. Yellow pigment and smooth dome shaped was the morphology of this species on L-J medium. On Middlebrooke 7H10 agar, strain DSM 44368 of Mycobacterium elephantis shows this previously stated morphology as well as another described as cream colored. With the onset of age, the yellow pigmentation ensues for DSM 44368. M. elephantis is also a non-motile species, as is a characteristic of the genus Mycobacterium. Metabolism and physiology Scarce results have been recorded to show the metabolic properties of