“…These two species have only recently been differentiated satisfactorily by means of immunodiffusion analysis and lipid chromatography (Marks and Szulga, 1965;Beck, 1968 andJenkins, Marks, and Schaefer, 1971) and their relative importance as pathogens is confused by the earlier accounts of infections in which all isolates are termed M. fortuitum. Both species are capable of causing abscesses after the injection of contaminated drugs or vaccines (Cruz, 1938;Limbos, Bretey, Jadin, and Brutsaent, 1961;Vandepitte, Desmyter, Brochier, and Gatti 1962;Owen, Smith, and Coultras, 1963;Beck, 1965;Clapper and Whitcombe, 1967;Canilang and Armstrong, 1968;and Vandepitte, Desmyter, and Gatti, 1969). Inman, Beck, Brown, and Stanford (1969) described 12 patients in Britain who developed injection abscessescaused by M. cheloneiafter receiving histamine from multidose vials.…”