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Costa-Ribeiro A, Lamas A, Mora A, Prado M, Garrido-Maestu A. Moving towards on-site detection of Shiga toxin-producing Escherichia coli in ready-to-eat leafy greens. Curr Res Food Sci 2024; 8:100716. [PMID: 38511154 PMCID: PMC10950744 DOI: 10.1016/j.crfs.2024.100716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 03/01/2024] [Accepted: 03/06/2024] [Indexed: 03/22/2024] Open
Abstract
Rapid identification of Shiga toxin-producing Escherichia coli, or STEC, is of utmost importance to assure the innocuousness of the foodstuffs. STEC have been implicated in outbreaks associated with different types of foods however, among them, ready-to-eat (RTE) vegetables are particularly problematic as they are consumed raw, and are rich in compounds that inhibit DNA-based detection methods such as qPCR. In the present study a novel method based on Loop-mediated isothermal amplification (LAMP) to overcome the limitations associated with current molecular methods for the detection of STEC in RTE vegetables targeting stx1 and stx2 genes. In this sense, LAMP demonstrated to be more robust against inhibitory substances in food. In this study, a comprehensive enrichment protocol was combined with four inexpensive DNA extraction protocols. The one based on silica purification enhanced the performance of the method, therefore it was selected for its implementation in the final method. Additionally, three different detection chemistries were compared, namely real-time fluorescence detection, and two end-point colorimetric strategies, one based on the addition of SYBR Green, and the other based on a commercial colorimetric master mix. After optimization, all three chemistries demonstrated suitable for the detection of STEC in spiked RTE salad samples, as it was possible to reach a LOD50 of 0.9, 1.4, and 7.0 CFU/25 g for the real-time, SYBR and CC LAMP assays respectively. All the performance parameters reached values higher than 90 %, when compared to a reference method based on multiplex qPCR. More specifically, the analytical sensitivity was 100, 90.0 and 100 % for real-time, SYBR and CC LAMP respectively, the specificity 100 % for all three assays, and accuracy 100, 96 and 100 %. Finally, a high degree of concordance was also obtained (1, 0.92 and 1 respectively). Considering the current technological advances, the method reported, using any of the three detection strategies, demonstrated suitable for their implementation in decentralized settings, with low equipment resources.
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Affiliation(s)
- Ana Costa-Ribeiro
- International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga s/n, 4715-330, Braga, Portugal
- Department of Biochemistry, Genetics and Immunology, University of Vigo, 36310, Vigo, Spain
| | - Alexandre Lamas
- Food Hygiene, Inspection and Control Laboratory (Lhica), Department of Analytical Chemistry, Nutrition, and Bromatology, Veterinary School, Campus Terra, Universidade de Santiago de Compostela (USC), 27002, Lugo, Spain
| | - Azucena Mora
- Laboratorio de Referencia de E. coli (LREC), Dpto. de Microbioloxía e Parasitoloxía, Facultade de Veterinaria, Universidade de Santiago de Compostela (USC), Lugo, Spain
- Instituto de Investigación Sanitaria de Santiago de Compostela (IDIS), Santiago, Spain
| | - Marta Prado
- International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga s/n, 4715-330, Braga, Portugal
- Food Hygiene, Inspection and Control Laboratory (Lhica), Department of Analytical Chemistry, Nutrition, and Bromatology, Veterinary School, Campus Terra, Universidade de Santiago de Compostela (USC), 27002, Lugo, Spain
| | - Alejandro Garrido-Maestu
- International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga s/n, 4715-330, Braga, Portugal
- Laboratory of Microbiology and Technology of Marine Products (MicroTEC), Instituto de Investigaciones Marinas (IIM), CSIC, Eduardo Cabello, 6, 36208, Vigo, Spain
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Costa-Ribeiro A, Lamas A, Prado M, Garrido-Maestu A. Evaluation of the Novel mTA10 Selective Broth, MSB, for the Co-Enrichment and Detection of Salmonella spp., Escherichia coli O157 and Listeria monocytogenes in Ready-to-Eat Salad Samples. Foods 2023; 13:63. [PMID: 38201091 PMCID: PMC10778508 DOI: 10.3390/foods13010063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 12/19/2023] [Accepted: 12/21/2023] [Indexed: 01/12/2024] Open
Abstract
Multiplex assays implementing DNA-based methods have been demonstrated as suitable alternatives to culture-based microbiological methods; however, in most cases, they still require a suitable enrichment step. Finding suitable enrichment conditions for different bacteria may result in challenges. In the present study, a novel selective broth named MSB (mTA10 selective broth) was formulated for the simultaneous recovery of Salmonella spp., E. coli O157:H7 and L. monocytogenes. Attention was paid to ensure the optimal enrichment of L. monocytogenes as its enrichment is more challenging. To this end, cellobiose was added to increase the growth of L. monocytogenes, and sodium pyruvate was also added to improve the recovery of stressed bacteria. Four selective agents were added, namely nalidixic acid, sodium cholate, lithium chloride and potassium tellurite, to control the growth of interfering microorganisms. It was concluded that the novel broth was suitable for the simultaneous enrichment of the target pathogens, allowing them to reach concentrations higher than 7 log CFU/mL for each bacterium in pure culture. Furthermore, all heavily contaminated ready-to-eat salad samples reached concentrations higher than 5 log CFU/g. Finally, after 24 h of enrichment of spiked salad, it was possible to detect concentrations below 10 CFU/25 g.
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Affiliation(s)
- Ana Costa-Ribeiro
- International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga s/n, 4715-330 Braga, Portugal; (A.C.-R.); (M.P.)
- Department of Biochemistry, Genetics and Immunology, University of Vigo, 36310 Vigo, Spain
| | - Alexandre Lamas
- Food Hygiene, Inspection and Control Laboratory (Lhica), Department of Analytical Chemistry, Nutrition and Bromatology, Veterinary School, Campus Terra, University of Santiago de Compostela (USC), 27002 Lugo, Spain;
| | - Marta Prado
- International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga s/n, 4715-330 Braga, Portugal; (A.C.-R.); (M.P.)
- Food Hygiene, Inspection and Control Laboratory (Lhica), Department of Analytical Chemistry, Nutrition and Bromatology, Veterinary School, Campus Terra, University of Santiago de Compostela (USC), 27002 Lugo, Spain;
| | - Alejandro Garrido-Maestu
- International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga s/n, 4715-330 Braga, Portugal; (A.C.-R.); (M.P.)
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Lamas A, Santos SB, Prado M, Garrido-Maestu A. Phage amplification coupled with loop-mediated isothermal amplification (PA-LAMP) for same-day detection of viable Salmonella Enteritidis in raw poultry meat. Food Microbiol 2023; 115:104341. [PMID: 37567642 DOI: 10.1016/j.fm.2023.104341] [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: 05/09/2023] [Revised: 07/10/2023] [Accepted: 07/10/2023] [Indexed: 08/13/2023]
Abstract
Salmonella Enteritidis is the main serotype responsible for human salmonellosis in the European Union. One of the main sources of Salmonella spp. in the food chain are poultry products, such as eggs or chicken meat. In recent years, molecular methods have become an alternative to culture dependent methods for the rapid screening of Salmonella spp. In this work, the strain S. Enteritidis S1400, and previously isolated and characterized bacteriophage PVP-SE2, were used to develop and evaluate a same-day detection method combining Phage Amplification and Loop-mediated isothermal amplification (PA-LAMP) to specifically detect viable S. Enteritidis in chicken breast. This method is based on the detection of the phage DNA rather than bacterial DNA. The virus is added to the sample during pre-enrichment in buffered peptone water, where it replicates in the presence of viable S. Enteritidis. The detection of phage DNA allows, on the one hand to detect viable bacteria, since viruses only replicate in them, and on the other hand to increase the sensitivity of the method since for each infected S. Enteritidis cell, hundreds of new viruses are produced. Two different PA-LAMP detection strategies were evaluated, a real time fluorescence and a naked-eye detection. The present method could down to 0.2 fg/μL of pure phage DNA and a concentration of viral particles of 2.2 log PFU/mL. After a short Salmonella recovery step of 3 h and a co-culture of 4 h of the samples with phage particles, both real-time fluorescence and naked-eye method showed a LoD95 of 6.6 CFU/25 g and a LoD50 of 1.5/25 g in spiked chicken breast samples. The entire detection process, including DNA extraction and LAMP analysis, can be completed in around 8 h. In the current proof-of-concept, the novel PA-LAMP obtained comparable results to those of the reference method ISO 6579, to detect Salmonella Enteritidis in poultry meat.
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Affiliation(s)
- Alexandre Lamas
- Food Hygiene, Inspection and Control Laboratory, Department of Analytical Chemistry, Nutrition and Bromatology, University of Santiago de Compostela, Spain
| | - Sílvio B Santos
- Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal; LABBELS - Associate Laboratory, 4800-122, Braga, Guimarães, Portugal
| | - Marta Prado
- International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga s/n, 4715-330, Braga, Portugal
| | - Alejandro Garrido-Maestu
- International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga s/n, 4715-330, Braga, Portugal.
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4
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Lamas A, Azinheiro S, Roumani F, Prado M, Garrido-Maestu A. Evaluation of the effect of outer primer structure, and inner primer linker sequences, in the performance of Loop-mediated isothermal amplification. Talanta 2023; 260:124642. [PMID: 37167680 DOI: 10.1016/j.talanta.2023.124642] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 04/27/2023] [Accepted: 05/02/2023] [Indexed: 05/13/2023]
Abstract
Loop-mediated isothermal amplification, or LAMP, is nowadays the most popular isothermal nucleic acid amplification technique. This technique implements a minimum of four primers, named outer (F3/B3) and inner primers (FIP/BIP). The inner primers hybridize in two distinct regions, and some studies have reported that the usage of a linker, typically composed of four thymines, in the middle of these primers can improve assay performance. In addition to this, dual-priming oligonucleotides, DPO, have been reported to provide highly specific reducing non-specific amplifications. Considering the large number of primers implemented in LAMP assays, in the current study the suitability of DPO primers replacing regular outer primers; and their combination with different linker sequences in the inner primers were explored. The results demonstrated that replacing standard F3/B3 by DPO primers does not significantly affect that overall performance of the assay, and provides additional stability to temperature changes. This observations were consistent regardless the type of linker implemented in the inner primers, out of which in the current study a linker composed of thymines significantly outperformed the other options tested, most likely due to a combination of sequence and physical structure.
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Affiliation(s)
- Alexandre Lamas
- Food Hygiene, Inspection and Control Laboratory, Department of Analytical Chemistry, Nutrition and Bromatology, Universidad de Santiago de Compostela, 27002, Lugo, Spain
| | - Sarah Azinheiro
- International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga s/n, 4715-330, Braga, Portugal; Department of Analytical Chemistry, Nutrition and Food Science, Faculty of Veterinary Science, University of Santiago de Compostela, 27002, Lugo, Spain
| | - Foteini Roumani
- International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga s/n, 4715-330, Braga, Portugal; Department of Analytical Chemistry, Nutrition and Food Science, Faculty of Veterinary Science, University of Santiago de Compostela, 27002, Lugo, Spain
| | - Marta Prado
- International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga s/n, 4715-330, Braga, Portugal
| | - Alejandro Garrido-Maestu
- International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga s/n, 4715-330, Braga, Portugal.
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Maciel C, Silva NFD, Teixeira P, Magalhães JMCS. Development of a Novel Phagomagnetic-Assisted Isothermal DNA Amplification System for Endpoint Electrochemical Detection of Listeria monocytogenes. BIOSENSORS 2023; 13:bios13040464. [PMID: 37185539 PMCID: PMC10136355 DOI: 10.3390/bios13040464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 03/27/2023] [Accepted: 03/29/2023] [Indexed: 05/17/2023]
Abstract
The hitherto implemented Listeria monocytogenes detection techniques are cumbersome or require expensive non-portable instrumentation, hindering their transposition into on-time surveillance systems. The current work proposes a novel integrated system resorting to loop-mediated isothermal amplification (LAMP), assisted by a bacteriophage P100-magnetic platform, coupled to an endpoint electrochemical technique, towards L. monocytogenes expeditious detection. Molybdophosphate-based optimization of the bacterial phagomagnetic separation protocol allowed the determination of the optimal parameters for its execution (pH 7, 25 °C, 32 µg of magnetic particles; 60.6% of specific capture efficiency). The novel LAMP method targeting prfA was highly specific, accomplishing 100% inclusivity (for 61 L. monocytogenes strains) and 100% exclusivity (towards 42 non-target Gram-positive and Gram-negative bacteria). As a proof-of-concept, the developed scheme was successfully validated in pasteurized milk spiked with L. monocytogenes. The phagomagnetic-based approach succeeded in the selective bacterial capture and ensuing lysis, triggering Listeria DNA leakage, which was efficiently LAMP amplified. Methylene blue-based electrochemical detection of LAMP amplicons was accomplished in 20 min with remarkable analytical sensitivity (1 CFU mL-1). Hence, the combined system presented an outstanding performance and robustness, providing a 2.5 h-swift, portable, cost-efficient detection scheme for decentralized on-field application.
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Affiliation(s)
- Cláudia Maciel
- Laboratório Associado, Escola Superior de Biotecnologia, CBQF-Centro de Biotecnologia e Química Fina, Universidade Católica Portuguesa, Rua Diogo Botelho 1327, 4169-005 Porto, Portugal
| | - Nádia F D Silva
- REQUIMTE/LAQV, Departamento de Engenharia Química, Faculdade de Engenharia, Universidade do Porto, 4200-465 Porto, Portugal
| | - Paula Teixeira
- Laboratório Associado, Escola Superior de Biotecnologia, CBQF-Centro de Biotecnologia e Química Fina, Universidade Católica Portuguesa, Rua Diogo Botelho 1327, 4169-005 Porto, Portugal
| | - Júlia M C S Magalhães
- REQUIMTE/LAQV, Departamento de Engenharia Química, Faculdade de Engenharia, Universidade do Porto, 4200-465 Porto, Portugal
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Azinheiro S, Roumani F, Costa-Ribeiro A, Prado M, Garrido-Maestu A. Application of MinION sequencing as a tool for the rapid detection and characterization of Listeria monocytogenes in smoked salmon. Front Microbiol 2022; 13:931810. [PMID: 36033887 PMCID: PMC9399719 DOI: 10.3389/fmicb.2022.931810] [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: 04/29/2022] [Accepted: 07/15/2022] [Indexed: 11/13/2022] Open
Abstract
Microbial pathogens may be present in different types of foods, and hence the development of novel methods to assure consumers' safeness is of great interest. Molecular methods are known to provide sensitive and rapid results; however, they are typically targeted approaches. In recent years, the advent of non-targeted approaches based on next-generation sequencing (NGS) has emerged as a rational way to proceed. This technology allows for the detection of several pathogens simultaneously. Furthermore, with the same set of data, it is possible to characterize the microorganisms in terms of serotype, virulence, and/ or resistance genes, among other molecular features. In the current study, a novel method for the detection of Listeria monocytogenes based on the "quasimetagenomics" approach was developed. Different enrichment media and immunomagnetic separation (IMS) strategies were compared to determine the best approach in terms of L. monocytogenes sequences generated from smoked salmon samples. Finally, the data generated were analyzed with a user-friendly workflow that simultaneously provided the species identification, serotype, and antimicrobial resistance genes. The new method was thoroughly evaluated against a culture-based approach, using smoked salmon inoculated with L. monocytogenes as the matrix of choice. The sequencing method reached a very low limit of detection (LOD50, 1.2 CFU/ 25 g) along with high diagnostic sensitivity and specificity (100%), and a perfect correlation with the culture-based method (Cohen's k = 1.00). Overall, the proposed method overcomes all the major limitations reported for the implementation of NGS as a routine food testing technology and paves the way for future developments taking its advantage into consideration.
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Affiliation(s)
- Sarah Azinheiro
- Food Quality and Safety Research Group, International Iberian Nanotechnology Laboratory, Braga, Portugal
- Department of Analytical Chemistry, Nutrition and Food Science, Faculty of Veterinary Science, University of Santiago de Compostela, Lugo, Spain
| | - Foteini Roumani
- Food Quality and Safety Research Group, International Iberian Nanotechnology Laboratory, Braga, Portugal
- Department of Analytical Chemistry, Nutrition and Food Science, Faculty of Veterinary Science, University of Santiago de Compostela, Lugo, Spain
| | - Ana Costa-Ribeiro
- Food Quality and Safety Research Group, International Iberian Nanotechnology Laboratory, Braga, Portugal
- Department of Biochemistry, Genetics and Immunology, University of Vigo, Vigo, Spain
| | - Marta Prado
- Food Quality and Safety Research Group, International Iberian Nanotechnology Laboratory, Braga, Portugal
| | - Alejandro Garrido-Maestu
- Food Quality and Safety Research Group, International Iberian Nanotechnology Laboratory, Braga, Portugal
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7
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Du J, Liu J, Liu K, Zhao D, Sagratini G, Tao J, Bai Y. Development of a fluorescent test strip sensor based on surface positively-charged magnetic bead separation for the detection of Listeria monocytogenes. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2022; 14:2188-2194. [PMID: 35611990 DOI: 10.1039/d2ay00384h] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Listeria monocytogenes is one of the major foodborne pathogens, which may cause serious food safety problems and illnesses in humans and animals. Consequently, sensitive, fast and reliable detection methods, as well as effective sample preparation methods are in great demand. In this study, a magnetic separation method based on a aptamer functionalized positively-charged magnetic beads (Fe3O4@aptamer) was established and a fluorescent test strip sensor was constructed for the rapid, sensitive and specific detection of Listeria monocytogenes. Benefiting from the dual recognition and signal amplification process of Fe3O4@aptamer enrichment and the polymerase chain reaction of the hly gene, the fluorescent strip sensor for the detection of Listeria monocytogenes was determined to be reliable and sensitive, with a linear curve obtained in the range of 1.0 × 102 to 1.9 × 108 CFU mL-1, and a detection limit of 1.0 × 102 CFU mL-1. The detection was achieved in 3 h without culture enrichment. Furthermore, the developed method was successfully applied for the detection of Listeria monocytogenes in pork tenderloin, with the recoveries ranging from 91.1% to 97.1%, and a coefficient of variation of less than 23.4%, revealing the feasible and reliable application of this method in practical samples. The proposed fluorescent strip sensor is rapid, sensitive and specific, giving it great application prospects for use in the field of pathogenic bacterium detection.
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Affiliation(s)
- Juan Du
- College of Food and Biological Engineering, Zhengzhou University of Light Industry, Zhengzhou, China.
- Henan Key Laboratory of Cold Chain Food Quality and Safety Control, Zhengzhou, China
- Henan Collaborative Innovation Center of Food Production and Safety, Zhengzhou, China
| | - Jialei Liu
- College of Food and Biological Engineering, Zhengzhou University of Light Industry, Zhengzhou, China.
| | - Kai Liu
- College of Food and Biological Engineering, Zhengzhou University of Light Industry, Zhengzhou, China.
| | - Dianbo Zhao
- College of Food and Biological Engineering, Zhengzhou University of Light Industry, Zhengzhou, China.
- Henan Key Laboratory of Cold Chain Food Quality and Safety Control, Zhengzhou, China
- Henan Collaborative Innovation Center of Food Production and Safety, Zhengzhou, China
| | - Gianni Sagratini
- School of Pharmacy, University of Camerino, via Madonna delle Carceri 9/B, Camerino, 62032, Italy
| | - Jing Tao
- College of Food and Biological Engineering, Zhengzhou University of Light Industry, Zhengzhou, China.
- School of Pharmacy, University of Camerino, via Madonna delle Carceri 9/B, Camerino, 62032, Italy
| | - Yanhong Bai
- College of Food and Biological Engineering, Zhengzhou University of Light Industry, Zhengzhou, China.
- Henan Key Laboratory of Cold Chain Food Quality and Safety Control, Zhengzhou, China
- Henan Collaborative Innovation Center of Food Production and Safety, Zhengzhou, China
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Slipchip-based immunomagnetic separation combined with loop-mediated isothermal amplification for rapid detection of Bacillus cereus with tetracycline resistance gene tetL in pasteurized milk. Food Control 2022. [DOI: 10.1016/j.foodcont.2022.109122] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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9
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Development and evaluation of a real-time fluorescence, and naked-eye colorimetric, loop-mediated isothermal amplification-based method for the rapid detection of spoilage fungi in fruit preparations. Food Control 2022. [DOI: 10.1016/j.foodcont.2021.108784] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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10
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Mu D, Zhou D, Xie G, Liu J, Wang Z, Xiong Q, Xu H. Real-time recombinase-aided amplification with PMAxx for the rapid detection of viable Escherichia coli O157:H7 in milk. J Dairy Sci 2022; 105:1028-1038. [PMID: 34998542 DOI: 10.3168/jds.2021-21074] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 10/21/2021] [Indexed: 11/19/2022]
Abstract
Escherichia coli O157:H7, the causative agent of thrombotic thrombocytopenic purpura and hemolytic uremic syndrome in humans, generates a effective harm to community health because of its high pathogenicity. A real-time recombinase-aided amplification (rRAA) is an emerging method for nucleic acid detection. However, genomic DNA of bacteria could exist in food and the environment for a long time after death and could be amplified by rRAA assay, resulting in false-positive signal; thus, developing a fast and sensitive method is necessary to detect viable foodborne pathogens in food products. In our research, rRAA assay coupled with an enhanced nucleic acid binding dye named improved propidium monoazide (PMAxx) was established and applied in viable E. coli O157:H7 identification in skim milk. The PMAxx could eliminate interference from dead bacteria by permeating impaired membranes and covalently linking to DNA to prevent DNA amplification. The PMAxx-rRAA assay was performed with high sensitivity and good specificity. The PMAxx-rRAA assay could detect as low as 5.4 × 100 cfu/mL of viable E. coli O157:H7 in pure culture, and 7.9 × 100 cfu/mL of viable E. coli O157:H7 in skim milk. In addition, the PMAxx-rRAA assay was performed in the presence of a high concentration of dead bacteria or nontarget bacteria in skim milk to verify the capacity to resist interference from dead bacteria and nontarget bacteria. Therefore, the established PMAxx-rRAA assay is a valuable tool for the identification of viable E. coli O157:H7 in complex food matrix.
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Affiliation(s)
- Dan Mu
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, PR China
| | - Donggen Zhou
- Ningbo International Travel Healthcare Center (Ningbo Customs Port Outpatient Department), Ningbo, 315010, PR China
| | - Guoyang Xie
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, PR China
| | - Ju Liu
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, PR China
| | - Zhengzheng Wang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, PR China
| | - Qin Xiong
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, PR China
| | - Hengyi Xu
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, PR China.
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Zhu L, Hao H, Ding C, Gan H, Jiang S, Zhang G, Bi J, Yan S, Hou H. A Novel Photoelectrochemical Aptamer Sensor Based on CdTe Quantum Dots Enhancement and Exonuclease I-Assisted Signal Amplification for Listeria monocytogenes Detection. Foods 2021; 10:2896. [PMID: 34945447 PMCID: PMC8701101 DOI: 10.3390/foods10122896] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 11/14/2021] [Accepted: 11/16/2021] [Indexed: 11/16/2022] Open
Abstract
To achieve the rapid detection of Listeria monocytogenes, this study used aptamers for the original identification and built a photoelectrochemical aptamer sensor using exonuclease-assisted amplification. Tungsten trioxide (WO3) was used as a photosensitive material, was modified with gold nanoparticles to immobilize complementary DNA, and amplified the signal by means of the sensitization effect of CdTe quantum dots and the shearing effect of Exonuclease I (Exo I) to achieve high-sensitivity detection. This strategy had a detection limit of 45 CFU/mL in the concentration range of 1.3 × 101-1.3 × 107 CFU/mL. The construction strategy provides a new way to detect Listeria monocytogenes.
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Affiliation(s)
- Liangliang Zhu
- Department of Inorganic Nonmetallic Materials Engineering, Dalian Polytechnic University, Dalian 116034, China; (L.Z.); (C.D.); (H.G.); (S.J.); (S.Y.)
| | - Hongshun Hao
- Department of Inorganic Nonmetallic Materials Engineering, Dalian Polytechnic University, Dalian 116034, China; (L.Z.); (C.D.); (H.G.); (S.J.); (S.Y.)
- Liaoning Key Lab for Aquatic Processing Quality and Safety, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, China; (G.Z.); (J.B.); (H.H.)
| | - Chao Ding
- Department of Inorganic Nonmetallic Materials Engineering, Dalian Polytechnic University, Dalian 116034, China; (L.Z.); (C.D.); (H.G.); (S.J.); (S.Y.)
| | - Hanwei Gan
- Department of Inorganic Nonmetallic Materials Engineering, Dalian Polytechnic University, Dalian 116034, China; (L.Z.); (C.D.); (H.G.); (S.J.); (S.Y.)
| | - Shuting Jiang
- Department of Inorganic Nonmetallic Materials Engineering, Dalian Polytechnic University, Dalian 116034, China; (L.Z.); (C.D.); (H.G.); (S.J.); (S.Y.)
| | - Gongliang Zhang
- Liaoning Key Lab for Aquatic Processing Quality and Safety, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, China; (G.Z.); (J.B.); (H.H.)
| | - Jingran Bi
- Liaoning Key Lab for Aquatic Processing Quality and Safety, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, China; (G.Z.); (J.B.); (H.H.)
| | - Shuang Yan
- Department of Inorganic Nonmetallic Materials Engineering, Dalian Polytechnic University, Dalian 116034, China; (L.Z.); (C.D.); (H.G.); (S.J.); (S.Y.)
| | - Hongman Hou
- Liaoning Key Lab for Aquatic Processing Quality and Safety, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, China; (G.Z.); (J.B.); (H.H.)
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Antibody- and nucleic acid-based lateral flow immunoassay for Listeria monocytogenes detection. Anal Bioanal Chem 2021; 413:4161-4180. [PMID: 34041576 DOI: 10.1007/s00216-021-03402-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 04/30/2021] [Accepted: 05/10/2021] [Indexed: 01/02/2023]
Abstract
Listeria monocytogenes is an invasive opportunistic foodborne pathogen and its routine surveillance is critical for protecting the food supply and public health. The traditional detection methods are time-consuming and require trained personnel. Lateral flow immunoassay (LFIA), on the other hand, is an easy-to-perform, rapid point-of-care test and has been widely used as an inexpensive surveillance tool. In recent times, nucleic acid-based lateral flow immunoassays (NALFIA) are also developed to improve sensitivity and specificity. A significant improvement in lateral flow-based assays has been reported in recent years, especially the ligands (antibodies, nucleic acids, aptamers, bacteriophage), labeling molecules, and overall assay configurations to improve detection sensitivity, specificity, and automated interpretation of results. In most commercial applications, LFIA has been used with enriched food/environmental samples to ensure detection of live cells thus prolonging the assay time to 24-48 h; however, with the recent improvement in LFIA sensitivity, results can be obtained in less than 8 h with shortened and improved enrichment practices. Incorporation of surface-enhanced Raman spectroscopy and/or immunomagnetic separation could significantly improve LFIA sensitivity for near-real-time point-of-care detection of L. monocytogenes for food safety and public health applications.
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