Cellular fatty acids as chemical markers for differentiation of Acinetobacter baumannii and Acinetobacter calcoaceticus / 生物医学与环境科学（英文）

ABSTRACT

<p><b>OBJECTIVE</b>Gas chromatography (GC) was used to investigate the cellular fatty acid (CFA) composition of 141 Acinetobacter baumannii and 32 A. calcoaceticus isolates from different locations in China and to find chemical markers to differentiate these two closely related bacteria.</p><p><b>METHODS</b>Whole cell fatty acid methyl esters (FAMEs) were obtained by saponification, methylation, and extraction for GC analysis, followed by a standardized Microbial Identification System (MIS) analysis.</p><p><b>RESULTS</b>All A. baumannii and A. calcoaceticus strains contained some major fatty acids, namely, 181 ω9c, 160, Sum In Feature 3, 120, 171ω8c, 3-OH-120, 170, Sum In Feature 2, 2-OH-120, and 180 compounds. Although most of the total CFAs are similar between A. baumannii and A. calcoaceticus strains, the ratios of two pairs of CFAs, i.e., Sum In Feature 3/181 ω9c versus 160/181 ω9c and Sum In Feature 3/181 ω9c versus unknown 12.484/181 ω9c fatty acids, could differentiate these two closely related bacteria. A. baumannii could be easily classified into two subgroups by plotting some ratios such as Sum In Feature 3/160 versus 170 and Sum In Feature 3/2-OH-120 versus 170 fatty acids.</p><p><b>CONCLUSION</b>The ratios of some CFAs could be used as chemical markers to distinguish A. baumannii from A. calcoaceticus.</p>