目的 探索应用光声光谱技术(photoacoustic spectroscopy,PAS)检测细菌气态挥发物(volatile compounds, VCs),作为一种无创、快速鉴定肺炎克雷伯菌的新方法。方法 利用PAS分别对肺炎克雷伯菌、鲍曼不动杆菌、大肠埃希菌、铜绿假单胞菌,以及空白对照组35 ℃培养24 h后产生的VCs进行检测,获得各细菌VCs和空白组的光声光谱图,并对检测结果进行分析比较,观察肺炎克雷伯菌与空白组、鲍曼不动杆菌、大肠埃希菌以及铜绿假单胞菌之间VCs光声光谱图的差异。结果 同种细菌之间及空白组之间光声光谱图基本重合,表明光声光谱分析仪性能稳定,实验重复性好;肺炎克雷伯菌VCs与空白组的光声光谱图存在明显差异,同时肺炎克雷伯菌VCs在1142和1160波数附近出现了波峰,而其他三组检测细菌(鲍曼不动杆菌、大肠埃希菌、铜绿假单胞菌)均未出现。结论 应用PAS通过对肺炎克雷伯菌VCs进行检测分析,可以将肺炎克雷伯菌与鲍曼不动杆菌、大肠埃希菌及铜绿假单胞菌进行区分,同时发现肺炎克雷伯菌的特征峰位于1142和1160波数段附近。

Objective To develop a noninvasive, quick and reliable method for the identification of Klebsiella pneumonia by detecting its volatile compounds (VCs) using photoacoustic spectroscopy (PAS).Methods Photoacoustic spectroscopy trace analyzer (PASTA) was used to conduct the analysis of bacterial volatile compounds (VCs), such as the volatile metabolites of Klebsiella pneumonia, Acinetobacter baumannii, Escherichia coli and Pseudomonas aeruginosa. The bacteria were cultured at 35 ℃ and measurement of VCs was performed after 24 hours. After that, the difference in the PAS of VCs between Klebsiella pneumonia, blank, Acinetobacter baumannii, Escherichia coli and Pseudomonas aeruginosa was observed.Results The PAS of VCs was basically similar between the same type of bacteria or between the blank groups, indicating that the adopted PASTA was of good performance and the experiment could be easily repeated. Obvious difference in the PAS of VCs was observed between Klebsiella pneumonia and the blank groups, suggesting that new VCs were generated by Klebsiella pneumonia. Besides, the PAS of VCs showed obvious peaks of Klebsiella pneumonia at wave 1142 and 1160 while the PAS of VCs of the other three types of bacteria was smooth at these two wave numbers.Conclusions Identification of Klebsiella pneumonia could be conducted by PAS. The characteristic peak may be located at wave 1142 and 1160.