Determination of the profile of fatty acids of 4 species of Shigella spp by chromatography of gases.

Shigella boydii, Shigella flexneri, Shigella dysenteriae and Shigella sonnei were identified using gas chromatography instead of the traditional techniques. Their acid methyl esters profiles were determined using a gas chromatograph Hewlett Packard 5890A and a RSL-150 heliflex capillary column. A total of 192 samples were analyzed both reference strains (ATCC 8700, INDRE B2188, B2194 and B2199) and environmental isolates. 12 fatty acids were included in the profiles from which 3-hydroxytetradecanoic acid (peak 12), trans 9-octadecanoic acid (peak 22), heptadecanoic acid (peak 18) and octadecanoic acid (peak 23), were the most important for the differentiation of the species analyzed.