Differentiation of Enterobacter sakazakii from Closely Related Enterobacter and Citrobacter Species Using Fatty Acid Profiles
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- 作者：Paul Whittaker ; Christine E. Keys ; Eric W. Brown ; Frederick S. Fry
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2007
- 出版时间：May 30, 2007
- 年：2007
- 卷：55
- 期：11
- 页码：4617 - 4623
- 全文大小：382K
- 年卷期：v.55,no.11(May 30, 2007)
- ISSN：1520-5118
文摘
Capillary gas chromatography with flame ionization detection (GC-FID) was used to determine thecellular fatty acid (CFA) profiles of 134 Enterobacter sakazakii strains, and these were compared tothe CFA profiles of other closely related Enterobacter and Citrobacter species. For GC-FID analysis,whole cell fatty acid methyl esters (FAMEs) from cells cultured on brain heart infusion (BHI) agar at37 
C for 24 h were obtained by saponification, methylation, and extraction into hexane/methyl tert-butyl ether. A database for E. sakazakii was prepared using fatty acid profiles from the 134 strains.Major fatty acids of E. sakazakii strains evaluated in this study were straight-chain 12:0, 14:0, and16:0, unsaturated 18:1 
7c, and 17:0 cyclo 7-8. Principal component analysis (PCA) based onCFA profiles for E. sakazakii strains shows separation of E. sakazakii subgroups A and B. The CFAprofiles for E. sakazakii and Enterobacter cloacae show that there are several fatty acids, 14:0, 17:0cyclo 7-8, 18:1 7c, and summed 16:1 6c/16:1 7c, that differ significantly between these twospecies. A PCA model based on CFA profiles for E. sakazakii strains clearly shows separation of E.sakazakii from closely related Enterobacter and Citrobacter species. Analysis of FAMEs from E.sakazakii strains grown on BHI agar by a rapid GC-FID method can provide a sensitive procedurefor the identification of this organism, and this analytical method provides a confirmatory procedure for the differentiation of E. sakazakii strains from closely related Enterobacter and Citrobacterspecies.
C for 24 h were obtained by saponification, methylation, and extraction into hexane/methyl tert-butyl ether. A database for E. sakazakii was prepared using fatty acid profiles from the 134 strains.Major fatty acids of E. sakazakii strains evaluated in this study were straight-chain 12:0, 14:0, and16:0, unsaturated 18:1 7c, and 17:0 cyclo 7-8. Principal component analysis (PCA) based onCFA profiles for E. sakazakii strains shows separation of E. sakazakii subgroups A and B. The CFAprofiles for E. sakazakii and Enterobacter cloacae show that there are several fatty acids, 14:0, 17:0cyclo 7-8, 18:1 7c, and summed 16:1 6c/16:1 7c, that differ significantly between these twospecies. A PCA model based on CFA profiles for E. sakazakii strains clearly shows separation of E.sakazakii from closely related Enterobacter and Citrobacter species. Analysis of FAMEs from E.sakazakii strains grown on BHI agar by a rapid GC-FID method can provide a sensitive procedurefor the identification of this organism, and this analytical method provides a confirmatory procedure for the differentiation of E. sakazakii strains from closely related Enterobacter and Citrobacterspecies.