Characterization of cellular fatty acids of listeria species and their effect on circulating blood monocytes

Listeria monocytogenes NCTC 7973, L. ivanovii SLCC 2379 and L. seeligeri SLCC 3954 were found to contain 5 - 7.8 % (dry weight) chloroform- soluble lipids. All species exhibited, nearly similar fatty acid esters profile with little difference when grown at 37 deg. C. The study revealed the abundance of odd chain saturated fatty acids in all the three species of Listeria. Among all, in particular ante-iso are more prevalent than iso- forms. The high percentage of the C15 fatty acid ester was characteristic of each species but with some differences in the relative amounts were observed. C19 and C22 fatty acid esters were characteristic of L. monocytogenes. Whole cells of L. monocytogenes and L. ivanovii induced strong monocytosis in the infected animals (rabbits, mice, and rats) of varying degree of susceptibility. Similar effect was observed with crude lipid extract of L.moncytogenes. No such response was observed even when live L. seeligri cells or crude lipid of L. ivanovii were injected. (author)