Julák Jaroslav, Procházková-Francisci Eva, Stránská Eva, Rosová Vlasta
Department of Immunology and Microbiology, 1st Medical Faculty, Charles University, Katerinská 32, 121 08 2 Prague, Czech Republic.
J Microbiol Methods. 2003 Jan;52(1):115-22. doi: 10.1016/s0167-7012(02)00148-3.
Head-space solid phase microextraction combined with gas chromatography (SPME-GC) was used for the determination of bacterial volatile fatty acid (VFA) patterns. The method was validated with cultures of reference bacterial strains. It was confirmed that VFA production depends on the composition of the cultivation medium, which limits accurate characterisation of particular bacterial species. A set of 195 clinical exudates of various origin and consistence was analysed using SPME-GC and compared with 73 samples extracted using tert-butyl methyl ether. Approximate agreement of VFA profiles with cultivation findings was found in most cases. However, 20.5% of clinical exudates with distinct VFA profiles appeared to be false-negative by cultivation. Using SPME-GC of exudates, the frequency of false-negative cultivations was higher than that of solvent extraction of exudates or blood cultures found previously. The described method is suitable for preliminary detection of bacteria, particularly non-sporulating anaerobes, in clinical samples. It can reveal false-negative findings due to cultivation. Analysis can be performed in 30 min without the need for cultivation.
顶空固相微萃取结合气相色谱法（SPME-GC）用于测定细菌挥发性脂肪酸（VFA）模式。该方法通过参考细菌菌株培养物进行了验证。已证实VFA的产生取决于培养基的组成，这限制了对特定细菌物种的准确表征。使用SPME-GC分析了195份不同来源和稠度的临床渗出液，并与73份用叔丁基甲醚提取的样本进行了比较。在大多数情况下，发现VFA谱与培养结果大致相符。然而，20.5%具有独特VFA谱的临床渗出液培养结果似乎为假阴性。使用渗出液的SPME-GC法，假阴性培养的频率高于先前发现的渗出液溶剂萃取法或血培养法。所述方法适用于临床样本中细菌的初步检测，特别是非芽孢厌氧菌。它可以揭示由于培养导致的假阴性结果。无需培养，30分钟内即可完成分析。
