Gas chromatographic assay of cellular fatty acids and alcohols for the identification of Mycobacterium species

Ten mycobacterial species obtained from 141 cultures isolated from clinical specimens were studied. The cultures were grown on solid medium and then a nalysed - after saponification, methylation, extraction with organic solven t and washing bf the organic phase - by capillary gas-liquid chromatography for fatty acid and Secondary alcohol composition. The absence of secondary alcohols was characteristic of M. genavense, M. tuberculosis and the follo wing Mycobacterium species with specific branched-chain fatty acids allowin g their direct identification: M. gordonae, M. kansasii and M. marinum. The presence of secondary alcohols was characteristic of M. avium, M. phlei, M . scrofulaceum, M. terrae and M. xenopi. In the case of M. xenopi direct id entification was made possible by the presence of a specific alcohol.