Analysis of Brucella cellular fatty acids

To acquire data of Brucella cellular fatty acids (CFAs) and probe into the possibility of utilizing CFAs information in typing Brucella, 19 reference strains were subjected to CFAs study. After all strains were inoculated on Brucella Agar plates, the cells were harvested, saponificated, methylated and extracted to provide fatty acid methylesters for gas chromatography (GC) analysis. Based on the CFAs data matrix, a dendrogram of 19 reference strains was generated by SPSS11.5 software package. The results showed that 19 reference strains were divided into five clusters: cluster 1 included B. suis (bv. 1, 2, 3, 5) and B. ovis; cluster 2 included B. abortus (bv. 3, 4, 5, 6) and B. melitensis (bv. 1, 2, 3); cluster 3 included B. abortus (bv. 1, 2, 7, 9) and B. neotomae; cluster 4 was B. suis (bv. 4); and cluster 5 was B. canis. Typing Brucella by GC analysis of CFAs is a good method to reflect drug resistance of Brucella, and the classification is beneficial for clinical therapy. It also provides a new result of typing and demonstrates that the traditional classification is not completely reasonable. CFAs analysis may identify B. suis (bv. 4) and B. canis.