ANALYST
·
2024
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IF 3.6
Wei Xu,Xue Zou,Yueting Ding,Qi Zhang,Yulan Song,Jin Zhang,Min Yang,Zhou Liu,Qiang Zhou,Dianlong Ge,Qiangling Zhang,Wencheng Song,Chaoqun Huang,Chengyin Shen,Yannan Chu
Ventilator-associated pneumonia (VAP) is a prevalent disease caused by microbial infection, resulting in significant morbidity and mortality within the intensive care unit (ICU). The rapid and accurate identification of pathogenic bacteria causing VAP can assist clinicians in formulating timely treatment plans. In this study, we attempted to differentiate bacterial species in VAP by utilizing the volatile organic compounds (VOCs) released by pathogens. We cultured 6 common bacteria in VAP in vitro, including Acinetobacter baumannii, Enterobacter cloacae, Escherichia coli, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and Staphylococcus aureus, which covered most cases of VAP infection in clinic. After the VOCs released by bacteria were collected in sampling bags, they were quantitatively detected by a proton transfer reaction-mass spectrometry (PTR-MS), and the characteristic ions were qualitatively analyzed through a fast gas chromatography-proton transfer reaction-mass spectrometry (FGC-PTR-MS). After conducting principal component analysis (PCA) and analysis of similarities (ANOSIM), we discovered that the VOCs released by 6 bacteria exhibited differentiation following 3 h of quantitative cultivation in vitro. Additionally, we further investigated the variations in the types and concentrations of bacterial VOCs. The results showed that by utilizing the differences in types of VOCs, 6 bacteria could be classified into 5 sets, except for A. baumannii and E. cloacae which were indistinguishable. Furthermore, we observed significant variations in the concentration ratio of acetaldehyde and methyl mercaptan released by A. baumannii and E. cloacae. In conclusion, the VOCs released by bacteria could effectively differentiate the 6 pathogens commonly associated with VAP, which was expected to assist doctors in formulating treatment plans in time and improve the survival rate of patients.
研究领域:
医学
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微生物学
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分析化学
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产品关联
DOI
PubMed
高影响因子
PHYSICA SCRIPTA
·
2025
·Vol. 100
·期 4
·045001
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IF 2.6
Yueting Ding,Yulan Song,Wei Xu,Qi Zhang,Jie Jin,Qiangling Zhang,Qu Liang,Xun Bao,Dianlong Ge,Yan Lu,Lei Xia,Yawei Liu,Chaoqun Huang,Qingmei Deng,Xue Zou,Chengyin Shen,Yannan Chu
Volatile organic compounds (VOCs) released by bacteria during proliferation have the potential to be used for rapid bacterial identification. VOCs change rapidy during the proliferation. However, the current studies are mostly based on single-point or long-time-interval sampling, which may lead to the omission of metabolic information. In this study, we developed an integrated device for bacterial culture-headspace injection-mass spectrometry detection. Using this device, we conducted high temporal resolution detection and analysis of headspace VOCs from E. coli, P. aeruginosa, and S. aureus. The detection interval was 10 min. The results showed that the VOCs released by the three bacteria caused the elevation of 30 ions in the mass spectrum. These ions exhibited complex regular changes in each bacterium. While the changing trends of some ions are significantly different among the three bacteria. For VOCs that exhibited a pattern of initially increasing and then decreasing, widening the sampling interval can lead to crucial information being missed. This may be an important factor contributing to differences in the detection of VOCs released by bacteria in previous studies. Therefore, the high temporal resolution detection method developed in this study can more accurately trace the changing trend of bacterial VOCs and provide technical support for bacterial identification methods based on VOC detection.
研究领域:
微生物学
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分析化学
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医学诊断
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产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2023
·
IF 8.8
Chongshan Yang,Dandan Duan,Chunwang Dong,Chuanxia Li,Guanglin Li,Yunhai Zhou,Yifan Gu,Yachao Liu,Chunjiang Zhao,Daming Dong
Aroma is a key factor used to evaluate tea quality. Illegal traders usually add essence to expired or substandard tea to improve its aroma so as to gain more profit. Traditional physical and chemical testing methods are time-consuming and costly. Furthermore, rapid detection techniques, such as near-infrared spectroscopy and machine vision, can only be used to detect adulterated powdered solid essences in tea. In this study, proton-transfer reaction mass spectrometry (PTR-MS) and Fourier-transform infrared spectroscopy (FTIR) were employed to detect volatile organic compounds (VOCs) in samples, and rapid detection of different tea adulterated liquid essence was achieved. The prediction accuracies of PTR-MS and FTIR reached over 0.941 and 0.957, respectively, and the minimum detection limits were lower than the actual used values in both. In this study, the different application scenarios of the two technologies are discussed based on their performance characteristics.
研究领域:
食品科学
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分析化学
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产品关联
DOI
PubMed
高影响因子
BIOSYSTEMS ENGINEERING
·
2019
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IF 2.983
Zun Man,Xiaorong Dai,Li Rong,Xianwang Kong,Shihao Ying,Yicong Xin,Dezhao Liu
The selection of sampling bags for odour measurement by olfactometry is critical and challenging since the loss of odorants during storage and transportation is usually high. However, there are no recommendations or limitations on the storage time for the standard Triangle odour bag method used in China. In order to optimise the selection of sampling bags, selected types of sampling bags (Fluode, BOPET, FEP and Tedlar) were tested and compared by using selected key odorants (dimethyl sulphide, 2-butanone, 2,3-butanedione, 4-methylphenol, indole , skatole, acetic acid, propanoic acid, butyric acid , valeric acid and hexanoic acid). The concentrations of key odorants were detected by PTR-MS. Firstly, background contamination was tested, with total amount of background pollutants produced by Tedlar being significantly higher than the other three types of sampling bags, while FEP and BOPET had less background contaminants. Secondly, recovery tests showed that the SOAV (sum of odour activity values) recoveries after 24 h of storage of Fluode, Tedlar, FEP and BOPET were 19.5%, 24.2%, 47.7% and 27.7%, respectively. FEP had better recovery than others, especially for the storage of 4-methylphenol (~55% recovery after 48 h), which is one of the key odorants emitted from intensive pig production. Finally, the recovery tests for 2,3-butanedione were performed under various conditions and results indicated that the storage of 2,3-butanedione in sampling bags depends on bag type (e.g. single bags or double bags), initial concentration level (10 ppbv, 100 ppbv or 1000 ppbv), the inner surface area-to-volume ratio and light condition (dark, natural light or LED light).
研究领域:
环境科学
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动物生产学
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DOI
高影响因子
Infection and Drug Resistance
·
2025
·
IF 2.9
Xuan Teng,Kexue Yu,Qi Zhang,Chengcheng Ma,Wenwen Chu,Chengyin Shen,Zhou Liu
Purpose To systematically analyse and identify volatile organic compounds (VOCs) released by clinical Klebsiella pneumoniae (K. pneumoniae) during growth via proton transfer reaction–mass spectrometry (PTR-MS), aiming to establish a rapid and accurate method for differentiating and identifying carbapenem-resistant Klebsiella pneumoniae (CRKP) and KPC and NDM producers.Methods Nonrepetitive clinical strains isolated from patient specimens were collected from September 2021 to May 2025. The strains were subjected to drug susceptibility testing and carbapenemase genotype identification via the VITEK2 system and polymerase chain reaction (PCR). The clinical strains were incubated in a closed system under the combined pressure of meropenem (MEM) and carbapenemase inhibitors for 3 h. PTR-MS was used to monitor the inhibition rate of the characteristic VOC ion signal intensity to obtain drug susceptibility information of KP and carbapenemase type. Characteristic ions were characterized via fast gas chromatography (FGC)-PTR-MS.Results A total of 105 clinical isolates, including 53 carbapenem-susceptible Klebsiella pneumoniae (CSKP) isolates and 52 CRKP (43 KPC-positive and 9 NDM-positive) isolates, were collected. With MEM, the sensitivity and specificity of PTR-MS for monitoring CRKP were 98.08% and 100.00%, respectively. In the case of MEM combined with different carbapenemase inhibitors, the assay was evaluated using a subset of isolates (n=31), comprising 22 KPC-positive and 9 NDM-positive strains. The sensitivity and specificity of PTR-MS for monitoring single KPC producers were 90.91% and 100.00%, respectively, and those for single NDM producers were 88.89% and 100.00%, respectively (kappa= 0.853 and 0.919 for KPC- and NDM-positive strains, respectively). FGC–PTR-MS analysis indicated that the VOCs corresponding to these characteristic ions were acetaldehyde, ethanol and acetic acid.Conclusion Real-time monitoring by PTR-MS of the dynamic release characteristics of specific VOC ions in the headspace of CRKP within 3 h under the combined stress of antibiotics and carbapenemase inhibitors can provide important information for rapidly identifying CRKP and the main clinical carbapenemase types.
研究领域:
微生物学
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临床诊断
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抗菌药物耐药
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分析化学
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感染性疾病
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产品关联
DOI
PubMed
高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2022
·Vol. 414
·期 26
·7647-7658
·
IF 4.478
Xu Wei,Zhang Jin,Ding Houwen,Ding Yueting,Zou Xue,Yang Min,Zhou Qiang,Liu Zhou,Zheng Ling,Zuo Heping,Ge Dianlong,Zhang Qiangling,Huang Chaoqun,Shen Chengyin,Chu Yannan
Exhaled volatile organic compounds (VOCs) have been widely applied for the study of disease biomarkers. Oral exhalation and nasal exhalation are two of the most common sampling methods. However, VOCs released from food residues and bacteria in the mouth or upper respiratory tract were also sampled and usually mistaken as that produced from body metabolism. In this study, exhalation from deep airway was first directly collected through intubation sampling and analyzed. The exhalation samples of 35 subjects were collected through a catheter, which was inserted into the trachea or bronchus through the mouth and upper respiratory tract. Then, the VOCs in these samples were detected by proton transfer reaction mass spectrometry (PTR-MS). In addition, fast gas chromatography proton transfer reaction mass spectrometry (FGC-PTR-MS) was used to further determine the VOCs with the same mass-to-charge ratios. The results showed that there was methanol, acetonitrile, ethanol, methyl mercaptan, acetone, isoprene, and phenol in the deep airway. Compared with that in oral exhalation, ethanol, methyl mercaptan, and phenol had lower concentrations. In detail, the median concentrations of ethanol, methyl mercaptan, and phenol were 7.3, 0.6, and 23.9 ppbv, while those in the oral exhalation were 80.0, 5.1, and 71.3 ppbv, respectively, which meant the three VOCs mainly originated from the food residues and bacteria in the mouth or upper respiratory tract, rather than body metabolism. The research results in our study can provide references for expiratory VOC research based on oral and nasal exhalation samplings, which are more feasible in clinical practice. Graphical abstract
研究领域:
医学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）