High Homogeneity of the Yersinia pestis Fatty Acid Composition

Abstract

The cellular fatty acid compositions of 29 strains ofYersinia pestis representing the global diversity of this species have been analyzed by gas-liquid chromatography to investigate the extent of fatty acid polymorphism in this microorganism. After culture standardization, all Y. pestis strains studied displayed some major fatty acids, namely, the 12:0, 14:0, 3-OH-14:0, 16:0, 16:1ω9cis, 17:0-cyc, and 18:1ω9trans compounds. The fatty acid composition of the various isolates studied was extremely homogeneous (average Bousfield's coefficient, 0.94) and the subtle variations observed did not correlate with epidemiological and genetic characteristics of the strains. Y. pestis major fatty acid compounds were analogous to those found in other Yersiniaspecies. However, when the ratios for the 12:0/16:0 and 14:0/16:0 fatty acids were plotted together, the genus Yersinia could be separated into three clusters corresponding to (i) nonpathogenic strains and species of Yersinia, (ii) pathogenicYersinia enterocolitica isolates, and (iii) Yersinia pseudotuberculosis and Y. pestis strains. The grouping of the two latter species into the same cluster was also demonstrated by their high Bousfield's coefficients (average, 0.89). Therefore, our results indicate that the fatty acid composition ofY. pestis is highly homogeneous and very close to that ofY. pseudotuberculosis.

Cellular fatty acids as chemical markers for differentiation of Yersinia pestis and Yersinia pseudotuberculosis

“…The minor fatty acids detected in the different strains of Y. pestis by this study, i.e., 3‐OH‐12:0, 15:0, 17:0, 18:0 and 18:1ω7c, were similar to those reported in other works (Jantzen and Lassen 1980; Samygin et al. 1994; Leclercq et al. 2000; Whittaker 2009).…”

“…Existences of other components such as 3‐OH‐14:0, 18:1ω7c, 12:0, 14:0, 15:0, 18:0 are similar to those in Y. pestis strains, which coincides with some of the previous reports (Frolov et al. 1989; Leclercq et al. 2000; Sel’nikova et al.…”

“…This result coincided with the former observations that fatty acid compositions of Y. pestis and Y. pseudotuberculosis were very similar, and the FAME analysis method could not differentiate the two species by simply comparing CFA profiles (Frolov et al. 1989; Leclercq et al. 2000; Sel’nikova et al.…”

“…We found the same major components with different proportions in Y. pestis compared to those reported previously (Tornabene 1973; Jantzen and Lassen 1980; Samygin et al. 1994; Leclercq et al. 2000) .…”

“…The growth medium was trypticase soy broth agar (Becton, Dickinson & Co., Sparks, MD). The cultures were incubated for 24 h at 28°C, allowing the population to reach the stationary growth phase where the fatty acid composition is rather stable (Leclercq et al. 2000).…”