<i>In vitro</i>
 discrimination of wound-associated bacteria by volatile compound profiling using selected ion flow tube-mass spectrometry

Slade, E. A.; Thorn, Robin; Lovering, Andrew; Young, Amber; Reynolds, Darren M.

doi:10.1111/jam.13473

Cited by 7 publications

(7 citation statements)

References 44 publications

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“…Over the past two decades, the mass spectrometry-based methodologies such as proton-transfer-reaction mass spectrometry (PTR-MS) and selected ion flow tube mass spectrometry (SIFT-MS), in addition to the gold-standard gas chromatography-mass spectrometry (GC-MS), have been used for the detection and analysis of gas-phase volatile organic compounds (VOCs) [ 1 , 2 , 3 , 4 ]. In recent years, secondary electrospray ionization mass spectrometry (SESI-MS) has also emerged for the studies of gas-phase VOCs from yeast, plant, bacteria, and breath [ 5 , 6 , 7 , 8 ].…”

Section: Introductionmentioning

confidence: 99%

Optimizing Secondary Electrospray Ionization High-Resolution Mass Spectrometry (SESI-HRMS) for the Analysis of Volatile Fatty Acids from Gut Microbiome

Lee

Zhu

2020

Metabolites

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Gut microbiota plays essential roles in maintaining gut homeostasis. The composition of gut microbes and their metabolites are altered in response to diet and remedial agents such as antibiotics. However, little is known about the effect of antibiotics on the gut microbiota and their volatile metabolites. In this study, we evaluated the impact of a moderate level of ampicillin treatment on volatile fatty acids (VFAs) of gut microbial cultures using an optimized real-time secondary electrospray ionization coupled with high-resolution mass spectrometry (SESI-HRMS). To evaluate the ionization efficiency, different types of electrospray solvents and concentrations of formic acid as an additive (0.01, 0.05, and 0.1%, v/v) were tested using VFAs standard mixture (C2–C7). As a result, the maximum SESI-HRMS signals of all studied m/z values were observed from water with 0.01% formic acid than those from the aqueous methanolic solutions. Optimal temperatures of sample inlet and ion chamber were set at 130 °C and 85 °C, respectively. SESI spray pressure at 0.5 bar generated the maximum intensity than other tested values. The optimized SESI-HRMS was then used for the analysis of VFAs in gut microbial cultures. We detected that the significantly elevated C4 and C7 VFAs in the headspace of gut microbial cultures six hours after ampicillin treatment (1 mg/L). In conclusion, our results suggested that the optimized SESI-HRMS method can be suitable for the analysis of VFAs from gut microbes in a rapid, sensitive, and non-invasive manner.

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Section: Introductionmentioning

confidence: 99%

Optimizing Secondary Electrospray Ionization High-Resolution Mass Spectrometry (SESI-HRMS) for the Analysis of Volatile Fatty Acids from Gut Microbiome

Lee

Zhu

2020

Metabolites

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“…In this study, the idea is to process every ion channel from each precursor as an independent variable. This approach has been used previously but a clear data processing workflow still needs to be established [13][14][15] . Such an original approach necessitated the establishment of a dedicated pre-processing strategy.…”

Section: Resultsmentioning

confidence: 99%

“…For this reason, it is an instrument of choice for targeted screening of VOCs 10 . Recently, SIFT-MS has been used for untargeted screening, using full scan MS mode 9,[13][14][15] . It is this untargeted full scan capacity that makes SIFT-MS a potential candidate for pattern-based breath profiling.…”

Section: Discussionmentioning

confidence: 99%

Multimodal combination of GC × GC-HRTOFMS and SIFT-MS for asthma phenotyping using exhaled breath

Stefanuto

Zanella

Vercammen

et al. 2020

Sci Rep

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Chronic inflammatory lung diseases impact more than 300 million of people worldwide. Because they are not curable, these diseases have a high impact on both the quality of life of patients and the healthcare budget. The stability of patient condition relies mostly on constant treatment adaptation and lung function monitoring. However, due to the variety of inflammation phenotypes, almost one third of the patients receive an ineffective treatment. To improve phenotyping, we evaluated the complementarity of two techniques for exhaled breath analysis: full resolving comprehensive two-dimensional gas chromatography coupled to high-resolution time-of-flight mass spectrometry (GC × GC-HRTOFMS) and rapid screening selected ion flow tube MS (SIFT-MS). GC × GC-HRTOFMS has a high resolving power and offers a full overview of sample composition, providing deep insights on the ongoing biology. SIFT-MS is usually used for targeted analyses, allowing rapid classification of samples in defined groups. In this study, we used SIFT-MS in a possible untargeted full-scan mode, where it provides pattern-based classification capacity. We analyzed the exhaled breath of 50 asthmatic patients. Both techniques provided good classification accuracy (around 75%), similar to the efficiency of other clinical tools routinely used for asthma phenotyping. Moreover, our study provides useful information regarding the complementarity of the two techniques.

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“…The developed method facilitates investigation of microbial metabolomics, including volatile metabolites produced by bacterial species associated with causing clinically relevant wound infection [38]. Selected ion flow tube mass spectrometry was used for real-time detection of the volatile compounds ammonia and hydrogen cyanide in the collagen wound biofilm model.…”

Section: Discussionmentioning

confidence: 99%

An in vitro collagen perfusion wound biofilm model; with applications for antimicrobial studies and microbial metabolomics

et al. 2019

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BackgroundThe majority of in vitro studies of medically relevant biofilms involve the development of biofilm on an inanimate solid surface. However, infection in vivo consists of biofilm growth on, or suspended within, the semi-solid matrix of the tissue, whereby current models do not effectively simulate the nature of the in vivo environment. This paper describes development of an in vitro method for culturing wound associated microorganisms in a system that combines a semi-solid collagen gel matrix with continuous flow of simulated wound fluid. This enables culture of wound associated reproducible steady state biofilms under conditions that more closely simulate the dynamic wound environment. To demonstrate the use of this model the antimicrobial kinetics of ceftazidime, against both mature and developing Pseudomonas aeruginosa biofilms, was assessed. In addition, we have shown the potential application of this model system for investigating microbial metabolomics by employing selected ion flow tube mass spectrometry (SIFT-MS) to monitor ammonia and hydrogen cyanide production by Pseudomonas aeruginosa biofilms in real-time.ResultsThe collagen wound biofilm model facilitates growth of steady-state reproducible Pseudomonas aeruginosa biofilms under wound like conditions. A maximum biofilm density of 1010 cfu slide− 1 was achieved by 30 h of continuous culture and maintained throughout the remainder of the experiment. Treatment with ceftazidime at a clinically relevant dose resulted in a 1.2–1.6 log reduction in biofilm density at 72 h compared to untreated controls. Treatment resulted in loss of complex biofilm architecture and morphological changes to bacterial cells, visualised using confocal microscopy. When monitoring the biofilms using SIFT-MS, ammonia and hydrogen cyanide levels peaked at 12 h at 2273 ppb (±826.4) and 138 ppb (±49.1) respectively and were detectable throughout experimentation.ConclusionsThe collagen wound biofilm model has been developed to facilitate growth of reproducible biofilms under wound-like conditions. We have successfully used this method to: (1) evaluate antimicrobial efficacy and kinetics, clearly demonstrating the development of antimicrobial tolerance in biofilm cultures; (2) characterise volatile metabolite production by P. aeruginosa biofilms, demonstrating the potential use of this method in metabolomics studies.

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In vitro discrimination of wound-associated bacteria by volatile compound profiling using selected ion flow tube-mass spectrometry

Cited by 7 publications

References 44 publications

Optimizing Secondary Electrospray Ionization High-Resolution Mass Spectrometry (SESI-HRMS) for the Analysis of Volatile Fatty Acids from Gut Microbiome

Optimizing Secondary Electrospray Ionization High-Resolution Mass Spectrometry (SESI-HRMS) for the Analysis of Volatile Fatty Acids from Gut Microbiome

Multimodal combination of GC × GC-HRTOFMS and SIFT-MS for asthma phenotyping using exhaled breath

An in vitro collagen perfusion wound biofilm model; with applications for antimicrobial studies and microbial metabolomics

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