1
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Liu J, Shan S, Lai W, Chen Q, Jing X, Li R, Tan Y, Liu D, Peng J. Phage based magnetic capture method as an aid for real time RPA detection of Salmonella spp. in milk. J Dairy Sci 2024:S0022-0302(24)00778-1. [PMID: 38754822 DOI: 10.3168/jds.2023-24237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 02/28/2024] [Indexed: 05/18/2024]
Abstract
Salmonella is a major cause of foodborne diseases worldwide. Conventional rapid assays for detecting Salmonella in real samples often encounter severe matrix interference or detect the limited number of species of a genus, resulting the inaccuracy of detection. In this study, we developed a method that combined phage-based magnetic capture with real time recombinase polymerase amplification (RPA) for the rapid, highly sensitive, and specific detection of Salmonella in milk with an ultra-low detection limit. The Felix O-1 phage-conjugated magnetic beads (O-1 pMBs) synthesized in this method showed excellent capture ability for Salmonella spp. and ideal specificity for non-Salmonella strains. After O-1 pMBs-based magnetic separation, the limit of detection (LOD) of the real time RPA assay was 50 cfu/mL in milk samples, which was significantly increased by a magnitude of 3-4 orders. The method exhibited a high sensitivity (compatibility) of 100% (14/14) for all tested Salmonella serotype strains and an ideal specificity (exclusivity) of 100% (7/7) for the tested non-Salmonella strains. The entire detection process including Salmonella capture, DNA extraction, and real time RPA detection was completed within 1.5 h. Furthermore, milk samples spiked with 10 cfu/25 mL of Salmonella were detected positive after cultured in buffered peptone water for only 3 h. Therefore, the proposed method could be an alternative for the rapid and accurate detection of Salmonella.
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Affiliation(s)
- Jie Liu
- State Key Laboratory of Food Science and Resources, Nanchang University, 235 East Nanjing Road, Nanchang 330047, China
| | - Shan Shan
- Jiangxi Province Key Laboratory of Diagnosing and Tracing of Foodborne Disease, Jiangxi Provincial Centre for Disease Control and Prevention, 555 East Beijing Road, Nanchang 330029, China.; College of Life Science, National R&D Center for Freshwater Fish Processing, Jiangxi Normal University, Nanchang 330022, China
| | - Weihua Lai
- State Key Laboratory of Food Science and Resources, Nanchang University, 235 East Nanjing Road, Nanchang 330047, China
| | - Qi Chen
- National Engineering Research Center for Bioengineering Drugs and the Technologies, Institute of Translational Medicine, Nanchang University, Nanchang, China
| | - Xudong Jing
- State Key Laboratory of Food Science and Resources, Nanchang University, 235 East Nanjing Road, Nanchang 330047, China
| | - Rui Li
- Jiangxi Province Key Laboratory of Diagnosing and Tracing of Foodborne Disease, Jiangxi Provincial Centre for Disease Control and Prevention, 555 East Beijing Road, Nanchang 330029, China.; Jiangxi Provincial Key Laboratory of Preventive Medicine, School of Public Health, Nanchang University, Nanchang 330019, China
| | - Yucheng Tan
- Jiangxi Province Key Laboratory of Diagnosing and Tracing of Foodborne Disease, Jiangxi Provincial Centre for Disease Control and Prevention, 555 East Beijing Road, Nanchang 330029, China.; Jiangxi Provincial Key Laboratory of Preventive Medicine, School of Public Health, Nanchang University, Nanchang 330019, China
| | - Daofeng Liu
- Jiangxi Province Key Laboratory of Diagnosing and Tracing of Foodborne Disease, Jiangxi Provincial Centre for Disease Control and Prevention, 555 East Beijing Road, Nanchang 330029, China..
| | - Juan Peng
- School of Food Science, Nanchang University, Nanchang 330047, China..
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2
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Wang Y, Wang X, Huang Y, Liu C, Yue T, Cao W. Identification and biotransformation analysis of volatile markers during the early stage of Salmonella contamination in chicken. Food Chem 2024; 431:137130. [PMID: 37591139 DOI: 10.1016/j.foodchem.2023.137130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 07/31/2023] [Accepted: 08/07/2023] [Indexed: 08/19/2023]
Abstract
Salmonella is one of the most prevalent foodborne pathogens in poultry and its products. Its rapid detection based on volatile organic compounds (VOC) has been widely accepted. However, the variation in the VOCs of Salmonella-contaminated chicken during the early stage (48 h) remains uncertain. Headspace-SPME-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and headspace-gas chromatography-ion migration spectroscopy (HS-GC-IMS) were used to identify VOCs and their variations after the chicken meat was contaminated with Salmonella. Chemometric and KEGG enrichment analyses were performed to identify VOC markers and their potential metabolic pathways. A total of 64 volatile compounds were detected using HS-GC-IMS, which showed a better differentiation than HS-SPME-GC-MS (45 volatile compounds) based on principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA). Fatty acid degradation was the main cause of VOC variation. 2-Propanol, hexadecane, 3-methylbutanol, acetic acid, propyl acetate, acetic acid methyl ester, and 3-butenenitrile were identified as VOC markers in the middle stage of decomposition, and 1-octen-3-ol was recognized as a VOC marker of Salmonella-contaminated chicken during the first 48 h of contamination. This provides a theoretical basis for the study of Salmonella contamination VOC markers in poultry meat.
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Affiliation(s)
- Yin Wang
- Department of Food Science, College of Food Science and Technology, Northwest University (China), Xi'an, Shaanxi 710069, China.
| | - Xian Wang
- Department of Food Science, College of Food Science and Technology, Northwest University (China), Xi'an, Shaanxi 710069, China
| | - Yuanyuan Huang
- Department of Food Science, College of Food Science and Technology, Northwest University (China), Xi'an, Shaanxi 710069, China
| | - Cailing Liu
- Department of Food Science, College of Food Science and Technology, Northwest University (China), Xi'an, Shaanxi 710069, China
| | - Tianli Yue
- Department of Food Science, College of Food Science and Technology, Northwest University (China), Xi'an, Shaanxi 710069, China
| | - Wei Cao
- Department of Food Science, College of Food Science and Technology, Northwest University (China), Xi'an, Shaanxi 710069, China
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3
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Baryzewska A, Roth C, Seeberger PH, Zeininger L. In situ Tracking of Exoenzyme Activity Using Droplet Luminescence Concentrators for Ratiometric Detection of Bacteria. ACS Sens 2023; 8:4143-4151. [PMID: 37933952 PMCID: PMC10683504 DOI: 10.1021/acssensors.3c01385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 09/26/2023] [Accepted: 10/17/2023] [Indexed: 11/08/2023]
Abstract
We demonstrate a novel, rapid, and cost-effective biosensing paradigm that is based on an in situ visualization of bacterial exoenzyme activity using biphasic Janus emulsion droplets. Sensitization of the droplets toward dominant extracellular enzymes of bacterial pathogens is realized via selective functionalization of one hemisphere of Janus droplets with enzyme-cleavable surfactants. Surfactant cleavage results in an interfacial tension increase at the respective droplet interface, which readily transduces into a microscopically detectable change of the internal droplet morphologies. A macroscopic fluorescence read-out of such morphological transitions is obtained via ratiometrically recording the angle-dependent anisotropic emission signatures of perylene-containing droplets from two different angles. The optical read-out method facilitates detection of marginal morphological responses of polydisperse droplet samples that can be easily produced in any environment. The performance of Janus droplets as powerful optical transducers and signal amplifiers is highlighted by rapid (<4 h) and cost-effective antibody and DNA-free identification of three major foodborne pathogens, with detection thresholds of below 10 CFU mL-1 for Salmonella and <102 to 103 CFU mL-1 for Listeria and Escherichia coli.
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Affiliation(s)
- Agata
W. Baryzewska
- Department
of Colloid Chemistry, Max Planck Institute
of Colloids and Interfaces, Am Muehlenberg 1, 14476 Potsdam, Germany
| | - Christian Roth
- Department
of Biomolecular Systems, Max Planck Institute
of Colloids and Interfaces, Am Muehlenberg 1, 14476 Potsdam, Germany
| | - Peter H. Seeberger
- Department
of Biomolecular Systems, Max Planck Institute
of Colloids and Interfaces, Am Muehlenberg 1, 14476 Potsdam, Germany
| | - Lukas Zeininger
- Department
of Colloid Chemistry, Max Planck Institute
of Colloids and Interfaces, Am Muehlenberg 1, 14476 Potsdam, Germany
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4
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Luo H, Hang Y, Zhu H, Zhong Q, Peng S, Gu S, Fang X, Hu L. Rapid Identification of Carbapenemase-Producing Klebsiella pneumoniae Using Headspace Solid-Phase Microextraction Combined with Gas Chromatography-Mass Spectrometry. Infect Drug Resist 2023; 16:2601-2609. [PMID: 37152404 PMCID: PMC10162101 DOI: 10.2147/idr.s404742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 04/14/2023] [Indexed: 05/09/2023] Open
Abstract
Background Carbapenemase-producing Klebsiella pneumoniae is an unprecedented threat to public health, and its detection remains challenging. Analysis of microbial volatile organic compounds (VOCs) may offer a rapid way to determine bacterial antibiotic susceptibility. Purpose The aim of this study was to explore the VOCs released by carbapenemase-producing carbapenem-resistant Klebsiella pneumoniae (CRKP) using headspace solid-phase microextraction/gas chromatography-mass spectrometry (HS-SPME/GC-MS). Methods Test bacteria were incubated in trypticase soy broth to the end of exponential growth phase, and imipenem was added in the middle time. Headspace VOCs were concentrated and analyzed using HS-SPME/GC-MS. Results The compound 3-methyl-1-butanol was found to be a biomarker among the 26 bacterial isolates (10 KPC-positive, 10 NDM-positive, 2 IMP-positive, 2 carbapenemase-negative CRKP, and 2 carbapenem-susceptible K. pneumonoiae). Conclusion This study explored a promising new strategy for the screening of carbapenemase-producing CRKP strains. Further research with larger sample sizes will potentially accelerate the application of biomarkers in routine microbiology.
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Affiliation(s)
- Hong Luo
- Jiangxi Provincial Key Laboratory of Medicine, Clinical Laboratory of the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, People’s Republic of China
| | - Yaping Hang
- Jiangxi Provincial Key Laboratory of Medicine, Clinical Laboratory of the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, People’s Republic of China
| | - Hongying Zhu
- Clinical Laboratory of Ganzhou People’s Hospital, Ganzhou, Jiangxi, People’s Republic of China
| | - Qiaoshi Zhong
- Jiangxi Provincial Key Laboratory of Medicine, Clinical Laboratory of the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, People’s Republic of China
| | - Suqin Peng
- Jiangxi Provincial Key Laboratory of Medicine, Clinical Laboratory of the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, People’s Republic of China
| | - Shumin Gu
- Jiangxi Provincial Key Laboratory of Medicine, Clinical Laboratory of the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, People’s Republic of China
| | - Xueyao Fang
- Jiangxi Provincial Key Laboratory of Medicine, Clinical Laboratory of the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, People’s Republic of China
| | - Longhua Hu
- Jiangxi Provincial Key Laboratory of Medicine, Clinical Laboratory of the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, People’s Republic of China
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5
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Dong B, Wu X, Wu S, Li H, Su QZ, Li D, Lin Q, Chen S, Zheng J, Zhu L, Zhong HN. Occurrence of volatile contaminants in recycled poly(ethylene terephthalate) by HS-SPME-GC×GC-QTOF-MS combined with chemometrics for authenticity assessment of geographical recycling regions. JOURNAL OF HAZARDOUS MATERIALS 2023; 445:130407. [PMID: 36444813 DOI: 10.1016/j.jhazmat.2022.130407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/10/2022] [Accepted: 11/14/2022] [Indexed: 06/16/2023]
Abstract
A comparison was performed on various methods detecting the volatile contaminants (VCs) in recycled poly(ethylene terephthalate) (rPET) flakes, the results demonstrated that head-space solid phase micro-extraction combined with comprehensive two-dimensional gas chromatograph-tandem quadrupole-time-of-flight mass spectrometry (HS-SPME-GC×GC-QTOF-MS) was a sensitive, effective, accurate method, and successfully applied to analyze 57 rPET flakes collected from different recycling plants in China. A total of 212 VCs were tentatively identified, and the possible source were associated with plastic, food, and cosmetics. 45 VCs are classified as high-priority compounds with toxicity level IV or V and may pose a risk to human health. Combined chemometrics for further analysis revealed that significant differences among these three geographical recycling regions. 6, 7, and 6 volatile markers were chosen based on VIP values and S-plot among plant1 plant 2 and plant 3, respectively. The markers differed significantly between recycled rPET samples in three geographical recycling regions based on chemometrics analysis. The initial classification rate and cross-validation accuracy were 100% on the identified VCs. These significant differences demonstrate that a systematic study is needed to obtain a comprehensive data on the contamination of rPET for food contact applications in China.
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Affiliation(s)
- Ben Dong
- National Reference Laboratory for Food Contact Material (Guangdong), Guangzhou Customs Technology Center, Guangzhou 510075, China
| | - Xuefeng Wu
- National Reference Laboratory for Food Contact Material (Guangdong), Guangzhou Customs Technology Center, Guangzhou 510075, China
| | - Siliang Wu
- National Reference Laboratory for Food Contact Material (Guangdong), Guangzhou Customs Technology Center, Guangzhou 510075, China
| | - Hanke Li
- National Reference Laboratory for Food Contact Material (Guangdong), Guangzhou Customs Technology Center, Guangzhou 510075, China
| | - Qi-Zhi Su
- National Reference Laboratory for Food Contact Material (Guangdong), Guangzhou Customs Technology Center, Guangzhou 510075, China
| | - Dan Li
- National Reference Laboratory for Food Contact Material (Guangdong), Guangzhou Customs Technology Center, Guangzhou 510075, China
| | - Qinbao Lin
- Key Laboratory of Product Packaging and Logistics, Packaging Engineering Institute, Jinan University, Zhuhai 519070, China; Working Group on Sustainable Food Contact Materials, Guangzhou 510070, China
| | - Sheng Chen
- National Reference Laboratory for Food Contact Material (Guangdong), Guangzhou Customs Technology Center, Guangzhou 510075, China; Working Group on Sustainable Food Contact Materials, Guangzhou 510070, China
| | - Jianguo Zheng
- National Reference Laboratory for Food Contact Material (Guangdong), Guangzhou Customs Technology Center, Guangzhou 510075, China
| | - Lei Zhu
- China National Center for Food Safety Risk Assessment, Beijing 100022, China.
| | - Huai-Ning Zhong
- National Reference Laboratory for Food Contact Material (Guangdong), Guangzhou Customs Technology Center, Guangzhou 510075, China; Working Group on Sustainable Food Contact Materials, Guangzhou 510070, China; State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, China.
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6
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Paramithiotis S. Molecular Targets for Foodborne Pathogenic Bacteria Detection. Pathogens 2023; 12:pathogens12010104. [PMID: 36678453 PMCID: PMC9865778 DOI: 10.3390/pathogens12010104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/30/2022] [Accepted: 01/04/2023] [Indexed: 01/11/2023] Open
Abstract
The detection of foodborne pathogenic bacteria currently relies on their ability to grow on chemically defined liquid and solid media, which is the essence of the classical microbiological approach. Such procedures are time-consuming and the quality of the result is affected by the selectivity of the media employed. Several alternative strategies based on the detection of molecular markers have been proposed. These markers may be cell constituents, may reside on the cell envelope or may be specific metabolites. Each marker provides specific advantages and, at the same time, suffers from specific limitations. The food matrix and chemical composition, as well as the accompanying microbiota, may also severely compromise detection. The aim of the present review article is to present and critically discuss all available information regarding the molecular targets that have been employed as markers for the detection of foodborne pathogens. Their strengths and limitations, as well as the proposed alleviation strategies, are presented, with particular emphasis on their applicability in real food systems and the challenges that are yet to be effectively addressed.
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Affiliation(s)
- Spiros Paramithiotis
- Laboratory of Food Process Engineering, Department of Food Science and Human Nutrition, Agricultural University of Athens, 75 Iera Odos St., 11855 Athens, Greece
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7
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Dong Q, Yue X, Li S, Hu M, Gao X, Yang M, Huang G, Xiong C, Fu G, Zhang J. A novel rapid detection method for Salmonella based on NMR macromolecular Gd biosensor. Lebensm Wiss Technol 2022. [DOI: 10.1016/j.lwt.2022.114138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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8
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Fang S, Liu S, Song J, Huang Q, Xiang Z. Recognition of pathogens in food matrixes based on the untargeted in vivo microbial metabolite profiling via a novel SPME/GC × GC-QTOFMS approach. Food Res Int 2021; 142:110213. [PMID: 33773687 DOI: 10.1016/j.foodres.2021.110213] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 01/22/2021] [Accepted: 01/24/2021] [Indexed: 10/22/2022]
Abstract
Foodborne diseases incurred by pathogenic bacteria are one of the major threats in food safety, and thus it is important to develop facile and effective recognition methodology of pathogens in food. Herein, a new automatic approach for detection of in vivo volatile metabolites emitted from foodborne pathogens was proposed by coupling solid phase microextraction (SPME) technique with a comprehensive two-dimensional gas chromatography quadrupole time-of-flight mass spectrometry (GC × GC-QTOFMS). A novel polymer composite based SPME probe which possessed high-coverage of microbial metabolites was utilized in this contribution to realize the sensitive extraction of untargeted metabolites. As a result, a total of 126 in vivo metabolites generated by the investigated pathogens were detected and identified, with 33, 29, 25, 21 and 18 volatile metabolites belonging to Shigella sonnei, Escherichia coli, Salmonella typhimurium, Vibrio parahaemolyticus and Staphylococcus aureus, respectively. Multivariate statistical analyses were applied for further analysis of metabolic data and separation of responsive metabolic features among different microbial systems were found, which were also successfully verified in foodstuffs contaminated by microorganisms. The growth trend of the potential volatile markers of each pathogen in food samples kept consistent with that of the pure strain incubated in medium during the whole incubation time. This study promotes the application of SPME technology in microbial volatile metabolomics and contributes to the development of new approaches for foodborne pathogens recognition.
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Affiliation(s)
- Shuting Fang
- Guangdong Provincial Engineering Research Center for Ambient Mass Spectrometry, Guangdong Provincial Key Laboratory of Emergency Test for Dangerous Chemicals, Institute of Analysis, Guangdong Academy of Sciences(China National Analytical Center, Guangzhou), Guangzhou 510070, China
| | - Shuqin Liu
- Guangdong Provincial Engineering Research Center for Ambient Mass Spectrometry, Guangdong Provincial Key Laboratory of Emergency Test for Dangerous Chemicals, Institute of Analysis, Guangdong Academy of Sciences(China National Analytical Center, Guangzhou), Guangzhou 510070, China
| | - Juyi Song
- School of Chemical Engineering, Guizhou Minzu University, Guiyang 550001, China
| | - Qihong Huang
- Guangdong Provincial Engineering Research Center for Ambient Mass Spectrometry, Guangdong Provincial Key Laboratory of Emergency Test for Dangerous Chemicals, Institute of Analysis, Guangdong Academy of Sciences(China National Analytical Center, Guangzhou), Guangzhou 510070, China
| | - Zhangmin Xiang
- Guangdong Provincial Engineering Research Center for Ambient Mass Spectrometry, Guangdong Provincial Key Laboratory of Emergency Test for Dangerous Chemicals, Institute of Analysis, Guangdong Academy of Sciences(China National Analytical Center, Guangzhou), Guangzhou 510070, China.
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9
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Abstract
Volatolomics allows us to elucidate cell metabolic processes in real time. In particular, a volatile organic compound (VOC) excreted from our bodies may be specific for a certain disease, such that measuring this VOC may afford a simple, fast, accessible and safe diagnostic approach. Yet, finding the optimal endogenous volatile marker specific to a pathology is non-trivial because of interlaboratory disparities in sample preparation and analysis, as well as high interindividual variability. These limit the sensitivity and specificity of volatolomics and its applications in biological and clinical fields but have motivated the development of induced volatolomics. This approach aims to overcome issues by measuring VOCs that result not from an endogenous metabolite but, rather, from the pathogen-specific or metabolic-specific enzymatic metabolism of an exogenous biological or chemical probe. In this Review, we introduce volatile-compound-based probes and discuss how they can be exploited to detect and discriminate pathogenic infections, to assess organ function and to diagnose and monitor cancers in real time. We focus on cases in which labelled probes have informed us about metabolic processes and consider the potential and drawbacks of the probes for clinical trials. Beyond diagnostics, VOC-based probes may also be effective tools to explore biological processes more generally.
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10
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Detection of Microbial Nitroreductase Activity by Monitoring Exogenous Volatile Organic Compound Production Using HS-SPME-GC-MS. SEPARATIONS 2020. [DOI: 10.3390/separations7040064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Development of a rapid approach for universal microbial detection is required in the healthcare, food and environmental sectors to aid with medical intervention, food safety and environmental protection. This research investigates the use of enzymatic hydrolysis of a substrate by a microorganism to generate a volatile organic compound (VOC). One such enzyme activity that can be used in this context is nitroreductase as such activity is prevalent across a range of microorganisms. A study was developed to evaluate a panel of 51 microorganisms of clinical interest for their nitroreductase activity. Two enzyme substrates, nitrobenzene and 1-fluoro-2-nitrobenzene, were evaluated for this purpose with evolution, after incubation, of the VOCs aniline and 2-fluoroaniline, respectively. Detection of the VOCs was done using headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) with obtained limits of quantitation (LOQ) of 0.17 and 0.03 µg/mL for aniline and 2-fluoroaniline, respectively. The results indicated that both enzyme substrates were reduced by the same 84.3% of microorganisms producing the corresponding volatile anilines which were detected using HS-SPME-GC-MS. It was found that nitroreductase activity could be detected after 6–8 h of incubation for the selected pathogenic bacteria investigated. This approach shows promise as a rapid universal microbial detection system.
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11
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Thompson R, Stephenson D, Sykes HE, Perry JD, Stanforth SP, Dean JR. Detection of β-alanyl aminopeptidase as a biomarker for Pseudomonas aeruginosa in the sputum of patients with cystic fibrosis using exogenous volatile organic compound evolution. RSC Adv 2020; 10:10634-10645. [PMID: 35492910 PMCID: PMC9051645 DOI: 10.1039/c9ra08386c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 03/02/2020] [Indexed: 12/15/2022] Open
Abstract
A novel, rapid and sensitive analytical method has been developed and applied to 105 sputum samples from patients with cystic fibrosis, including 5 samples from post-lung transplant patients. This new method is specifically targeted to measure β-alanyl aminopeptidase activity which is characteristic of some important Gram-negative pathogens. Of relevance to this study are Pseudomonas aeruginosa and pathogens of the Burkholderia cepacia complex both of which are commonly associated with respiratory infections as well as increased morbidity and mortality in adult cystic fibrosis patients. The analytical method involves the addition of a novel enzyme substrate (i.e. 3-amino-N-(3-fluorophenyl)propanamide) that interacts with β-alanyl aminopeptidase to generate an exogenous volatile organic compound 3-fluoroaniline (LOD 0.02 μg mL−1; LOQ 0.06 μg mL−1). 3-Fluoroaniline was determined at 20 times above its calculated limit of quantification in the sputum samples by HS-SPME-GC-MS and then the results compared with standard culture methods and bacterial identification using MALDI-TOF-MS. Detection of 3-fluoroaniline was possible after only 8 h incubation of the sputum samples with a 95% success rate; this increased to 100% at 24 h which was well within the typical routine timeframe of 48 h. To our knowledge, this is the first demonstration of detection of P. aeruginosa by use of a custom-designed substrate to liberate a detectable and unique VOC. The very high negative predictive value (100% in this study) means such an assay could be appropriate as a screening technique for patients who are not yet colonized by this pathogen. A novel, rapid and sensitive analytical method has been developed and applied to 105 sputum samples from patients with cystic fibrosis, including 5 samples from post-lung transplant patients.![]()
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Affiliation(s)
- Ryan Thompson
- Department of Applied Sciences
- Northumbria University
- Newcastle upon Tyne
- UK
| | - Dominic Stephenson
- Department of Applied Sciences
- Northumbria University
- Newcastle upon Tyne
- UK
- Department of Microbiology
| | - Hannah E. Sykes
- Department of Applied Sciences
- Northumbria University
- Newcastle upon Tyne
- UK
| | - John D. Perry
- Department of Microbiology
- Freeman Hospital
- Newcastle upon Tyne
- UK
| | | | - John R. Dean
- Department of Applied Sciences
- Northumbria University
- Newcastle upon Tyne
- UK
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12
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A single cell droplet microfluidic system for quantitative determination of food-borne pathogens. Talanta 2019; 209:120571. [PMID: 31892085 DOI: 10.1016/j.talanta.2019.120571] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 11/13/2019] [Accepted: 11/14/2019] [Indexed: 11/21/2022]
Abstract
Single-cell detection methods are already of great significance for many bioanalysis applications, and droplet microfluidics technology is understood as particularly a powerful tool. Salmonella infection is a major hygienic problem worldwide that causes major public health and economic damage, and preventing Salmonella outbreaks requires detection food-borne detection methods that are rapid, portable, and reliable, ideally without the need for complicated pre-treatment protocol steps. Herein, we present a single-cell-level analysis method based on droplet microfluidics that can sensitively and rapidly detect Salmonella directly from food samples. Specifically, this method achieves single-cell encapsulation of Salmonella in droplets of a growth medium with resazurin that enables fluorescence-based detection of pathogens within 5 h. The ratio of positive droplets in a Poisson Distribution is used for quantitation, and the detection limit of our system determined to be 50 CFU/mL, a value lower than conventional analytical methods for assessing Salmonella contamination. Our experimental results demonstrate the precise and highly sensitive performance of a single-cell-precision, droplet-based microfluidic chip analytical method for monitoring pathogenic bacteria in food. Beyond our example case of Salmonella detection from milk samples, our work lays the foundation for a new generation of microfluidics-based analytical technologies for both public health and food safety applications which can undoubtedly benefit from increases in the sensitivity and rapidity of food-borne pathogen detection.
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13
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Yang N, Yang T, Wang W, Chen H, Li W. Polydopamine modified polyaniline-graphene oxide composite for enhancement of corrosion resistance. JOURNAL OF HAZARDOUS MATERIALS 2019; 377:142-151. [PMID: 31158583 DOI: 10.1016/j.jhazmat.2019.05.063] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 04/03/2019] [Accepted: 05/25/2019] [Indexed: 06/09/2023]
Abstract
In this study, the composite of two-dimensional graphene oxide (GO) nanosheets and button-shaped polyaniline (PANI) was synthesized and further modified by polydopamine (PDA). The obtained PDA-PANI-GO composite was used to enhance the corrosion protection ability of nontoxic water-based alkyd varnish (WAV). The chemical composition, functional groups and surface morphologies of GO, PANI-GO and PDA-PANI-GO composites were characterized by XRD, FT-IR XPS and SEM. The anticorrosion performance was demonstrated by electrochemical impedance spectroscopy measurements and polarization tests. Due to the physical barrier effects and surface hydrophobicity of PANI-GO composite, the approaches of the caustic substances to the surface of the metal was inhibited, while the highly adhesive PDA molecules reinforced compatibility between fillers and WAV. As results, PDA-PANI-GO composite introduced WAV enhanced corrosion prevention performance. Under the optimal conditions, where the ratio of PDA to PANI-GO was kept at 2:1, the impedance values increased by over two orders of magnitude compared with bare steel.
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Affiliation(s)
- Ning Yang
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, PR China; Open Studio for Marine Corrosion and Protection, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266000, PR China; University of Chinese Academy of Sciences, Beijing, 100039, PR China
| | - Tao Yang
- College of Chemical Engineering and Technology, Sun Yat-sen University, Zhuhai, 519082, PR China
| | - Wei Wang
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, PR China; Open Studio for Marine Corrosion and Protection, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266000, PR China; University of Chinese Academy of Sciences, Beijing, 100039, PR China
| | - Huaiyin Chen
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, PR China; Open Studio for Marine Corrosion and Protection, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266000, PR China; University of Chinese Academy of Sciences, Beijing, 100039, PR China
| | - Weihua Li
- College of Chemical Engineering and Technology, Sun Yat-sen University, Zhuhai, 519082, PR China.
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