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Karaca B, Karakaya AB, Ozcan B, Coleri Cihan A. Rapid detection of
Geobacillus
and
Anoxybacillus
species by
quantitative qPCR (qPCR)
in commercial dairy products. J Food Saf 2022. [DOI: 10.1111/jfs.12964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Basar Karaca
- Department of Biology, Faculty of Sciences Ankara University Ankara Turkey
| | | | - Birgul Ozcan
- Department of Biology, Faculty of Art and Sciences Mustafa Kemal University Antakya Turkey
| | - Arzu Coleri Cihan
- Department of Biology, Faculty of Sciences Ankara University Ankara Turkey
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2
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Detection of spore forming Paenibacillus macerans in raw milk. J Microbiol Methods 2020; 177:106048. [PMID: 32890571 DOI: 10.1016/j.mimet.2020.106048] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 08/17/2020] [Accepted: 08/17/2020] [Indexed: 11/22/2022]
Abstract
Paenibacillus macerans can cause spoilage of milk during extended storage. However, the natural milk microbiota interferes with the enumeration of Paenibacillus species in raw milk. In this study, a qualitative SYBR Green real-time PCR assay based on the groEL gene was developed for detecting P. macerans (PMassay) in raw milk and compared with one designed for total Paenibacillus detection (TPassay). The specificity of the PMassay was confirmed against a panel of dairy-related spore forming isolates. In the presence of background DNA substituted up to 95%, P. macerans DNA could still be detected by the PMassay although interference occurred as non-target DNA substitution increased. The PMassay was sensitive (detection limit of 2 log CFU/ml in milk) and specific as non-P. macerans isolates gave a Ct > 30. After enrichment of raw milk for 7 days at 37 °C in Reinforced Clostridial Medium with D-cycloserine (RCM-D) under anaerobiosis, Paenibacillus was detected in 10 of the 16 raw milk samples tested. Enrichment in RCM-D yielded about 0.5 to 5.8 log CFU/ml total Paenibacillus and 0.3 to 4.6 log CFU/ml P. macerans in the samples. The assay could be useful in commercial settings, allowing a sensitive detection of P. macerans.
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3
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Ohkubo Y, Uchida K, Motoshima H, Katano N. Species-specific real-time PCR assay for enumeration of Anoxybacillus flavithermus and Geobacillus stearothermophilus spores in dairy products. Int Dairy J 2019. [DOI: 10.1016/j.idairyj.2019.01.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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4
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Agrimonti C, Bottari B, Sardaro MLS, Marmiroli N. Application of real-time PCR (qPCR) for characterization of microbial populations and type of milk in dairy food products. Crit Rev Food Sci Nutr 2017; 59:423-442. [DOI: 10.1080/10408398.2017.1375893] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Caterina Agrimonti
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Benedetta Bottari
- Department of Food and Drug Science, University of Parma, Parma, Italy
| | - Maria Luisa Savo Sardaro
- Department of Food and Drug Science, University of Parma, Parma, Italy; Department of Nutrition and Gastronomy, University San Raffaele Roma Srl, Rome, Italy
| | - Nelson Marmiroli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
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5
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Wunderlin T, Junier T, Paul C, Jeanneret N, Junier P. Physical Isolation of Endospores from Environmental Samples by Targeted Lysis of Vegetative Cells. J Vis Exp 2016:e53411. [PMID: 26863128 DOI: 10.3791/53411] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Endospore formation is a survival strategy found among some bacteria from the phylum Firmicutes. During endospore formation, these bacteria enter a morpho-physiological resting state that enhances survival under adverse environmental conditions. Even though endospore-forming Firmicutes are one of the most frequently enriched and isolated bacterial groups in culturing studies, they are often absent from diversity studies based on molecular methods. The resistance of the spore core is considered one of the factors limiting the recovery of DNA from endospores. We developed a method that takes advantage of the higher resistance of endospores to separate them from other cells in a complex microbial community using physical, enzymatic and chemical lysis methods. The endospore-only preparation thus obtained can be used for re-culturing or to perform downstream analysis such as tailored DNA extraction optimized for endospores and subsequent DNA sequencing. This method, applied to sediment samples, has allowed the enrichment of endospores and after sequencing, has revealed a large diversity of endospore-formers in freshwater lake sediments. We expect that the application of this method to other samples will yield a similar outcome.
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Affiliation(s)
| | | | | | | | - Pilar Junier
- Laboratory of Microbiology, University of Neuchatel;
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6
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Buehner KP, Anand S, Djira GD. Prevalence of thermoduric bacteria and spores in nonfat dry milk powders of Midwest origin. J Dairy Sci 2015; 98:2861-6. [DOI: 10.3168/jds.2014-8822] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 01/10/2015] [Indexed: 11/19/2022]
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7
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Development of a Multiplex-PCR assay for the rapid identification of Geobacillus stearothermophilus and Anoxybacillus flavithermus. Food Microbiol 2014; 43:41-9. [PMID: 24929881 DOI: 10.1016/j.fm.2014.05.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 04/29/2014] [Accepted: 05/02/2014] [Indexed: 11/21/2022]
Abstract
The presence of thermophilic bacilli in dairy products is indicator of poor hygiene. Their rapid detection and identification is fundamental to improve the industrial reactivity in the implementation of corrective and preventive actions. In this study a rapid and reliable identification of Geobacillus stearothermophilus and Anoxybacillus flavithermus was achieved by species-specific PCR assays. Two primer sets, targeting the ITS 16S-23S rRNA region and the rpoB gene sequence of the target species respectively, were employed. Species-specificity of both primer sets was evaluated by using 53 reference strains of DSMZ collection; among them, 13 species of the genus Geobacillus and 15 of the genus Anoxybacillus were represented. Moreover, 99 wild strains and 23 bulk cells collected from 24 infant formula powders gathered from several countries worldwide were included in the analyses. Both primer sets were highly specific and the expected PCR fragments were obtained only when DNA from G. stearothermophilus or A. flavithermus was used. After testing their specificity, they were combined in a Multiplex-PCR assay for the simultaneous identification of the two target species. The specificity of the Multiplex-PCR was evaluated by using both wild strains and bulk cells. Every analysis confirmed the reliable identification results provided by the single species-specific PCR methodology. The easiness, the rapidity (about 4 h from DNA isolation to results) and the reliability of the PCR procedures developed in this study highlight the advantage of their application for the specific detection and identification of the thermophilic species G. stearothermophilus and A. flavithermus.
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8
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Quantification of endospore-forming firmicutes by quantitative PCR with the functional gene spo0A. Appl Environ Microbiol 2013; 79:5302-12. [PMID: 23811505 DOI: 10.1128/aem.01376-13] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterial endospores are highly specialized cellular forms that allow endospore-forming Firmicutes (EFF) to tolerate harsh environmental conditions. EFF are considered ubiquitous in natural environments, in particular, those subjected to stress conditions. In addition to natural habitats, EFF are often the cause of contamination problems in anthropogenic environments, such as industrial production plants or hospitals. It is therefore desirable to assess their prevalence in environmental and industrial fields. To this end, a high-sensitivity detection method is still needed. The aim of this study was to develop and evaluate an approach based on quantitative PCR (qPCR). For this, the suitability of functional genes specific for and common to all EFF were evaluated. Seven genes were considered, but only spo0A was retained to identify conserved regions for qPCR primer design. An approach based on multivariate analysis was developed for primer design. Two primer sets were obtained and evaluated with 16 pure cultures, including representatives of the genera Bacillus, Paenibacillus, Brevibacillus, Geobacillus, Alicyclobacillus, Sulfobacillus, Clostridium, and Desulfotomaculum, as well as with environmental samples. The primer sets developed gave a reliable quantification when tested on laboratory strains, with the exception of Sulfobacillus and Desulfotomaculum. A test using sediment samples with a diverse EFF community also gave a reliable quantification compared to 16S rRNA gene pyrosequencing. A detection limit of about 10(4) cells (or spores) per gram of initial material was calculated, indicating this method has a promising potential for the detection of EFF over a wide range of applications.
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Rapid identification of dairy mesophilic and thermophilic sporeforming bacteria using DNA high resolution melt analysis of variable 16S rDNA regions. Int J Food Microbiol 2013; 165:175-83. [PMID: 23743474 DOI: 10.1016/j.ijfoodmicro.2013.05.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Revised: 05/01/2013] [Accepted: 05/04/2013] [Indexed: 11/23/2022]
Abstract
Due to their ubiquity in the environment and ability to survive heating processes, sporeforming bacteria are commonly found in foods. This can lead to product spoilage if spores are present in sufficient numbers and where storage conditions favour spore germination and growth. A rapid method to identify the major aerobic sporeforming groups in dairy products, including Bacillus licheniformis group, Bacillus subtilis group, Bacillus pumilus group, Bacillus megaterium, Bacillus cereus group, Geobacillus species and Anoxybacillus flavithermus was devised. This method involves real-time PCR and high resolution melt analysis (HRMA) of V3 (~70 bp) and V6 (~100 bp) variable regions in the 16S rDNA. Comparisons of HRMA curves from 194 isolates of the above listed sporeforming bacteria obtained from dairy products which were identified using partial 16S rDNA sequencing, allowed the establishment of criteria for differentiating them from each other and several non-sporeforming bacteria found in samples. A blinded validation trial on 28 bacterial isolates demonstrated complete accuracy in unambiguous identification of the 7 different aerobic sporeformers. The reliability of HRMA method was also verified using boiled extractions of crude DNA, thereby shortening the time needed for identification. The HRMA method described in this study provides a new and rapid approach to identify the dominant mesophilic and thermophilic aerobic sporeforming bacteria found in a wide variety of dairy products.
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10
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Yong X, Zhang R, Zhang N, Chen Y, Huang X, Zhao J, Shen Q. Development of a specific real-time PCR assay targeting the poly-γ-glutamic acid synthesis gene, pgsB, for the quantification of Bacillus amyloliquefaciens in solid-state fermentation. BIORESOURCE TECHNOLOGY 2013; 129:477-484. [PMID: 23266849 DOI: 10.1016/j.biortech.2012.11.092] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2012] [Revised: 11/17/2012] [Accepted: 11/20/2012] [Indexed: 06/01/2023]
Abstract
A TaqMan real-time PCR procedure was developed for specific detection and quantification of strains belonging to Bacillus amyloliquefaciens group. The primer pair pgsB726-f/pgsB791-r and the pgsB-probe were designed from one of the poly-γ-glutamic acid synthesis gene (pgsB) of B. amyloliquefaciens. The detection limit was approximately between 10(2)-10(3) cells/mL. A linear correlation between the log10 input pMD-pgsB plasmid DNA copies and the threshold cycle values were observed with a magnitude of linearity in the range of 9.415×10(3)-10(7) copies/mL for the standard curve, which exhibited a slope of -3.35 and an R2 value of 99.8%. Results of validation of this method with artificially contaminated and natural solid-state fermentation samples showed that it was suitable for specific and sensitive detection and quantification for the target strains in solid-state fermentation samples. This could be more useful to understand the fermentation starting strain and the final microbiological properties of fermentation products.
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Affiliation(s)
- Xiaoyu Yong
- Agricultural Ministry Key Lab of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Jiangsu Key Lab and Engineering Center for Solid Organic Waste Utilization, Nanjing Agricultural University, Nanjing 210095, China
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11
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Goh KM, Kahar UM, Chai YY, Chong CS, Chai KP, Ranjani V, Illias R, Chan KG. Recent discoveries and applications of Anoxybacillus. Appl Microbiol Biotechnol 2013; 97:1475-88. [PMID: 23324802 DOI: 10.1007/s00253-012-4663-2] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 12/15/2012] [Accepted: 12/17/2012] [Indexed: 11/26/2022]
Abstract
The Bacillaceae family members are a good source of bacteria for bioprocessing and biotransformation involving whole cells or enzymes. In contrast to Bacillus and Geobacillus, Anoxybacillus is a relatively new genus that was proposed in the year 2000. Because these bacteria are alkali-tolerant thermophiles, they are suitable for many industrial applications. More than a decade after the first report of Anoxybacillus, knowledge accumulated from fundamental and applied studies suggests that this genus can serve as a good alternative in many applications related to starch and lignocellulosic biomasses, environmental waste treatment, enzyme technology, and possibly bioenergy production. This current review provides the first summary of past and recent discoveries regarding the isolation of Anoxybacillus, its medium requirements, its proteins that have been characterized and cloned, bioremediation applications, metabolic studies, and genomic analysis. Comparisons to some other members of Bacillaceae and possible future applications of Anoxybacillus are also discussed.
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Affiliation(s)
- Kian Mau Goh
- Faculty of Biosciences and Bioengineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia.
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Ratphitagsanti W, Park E, Lee CS, Amos Wu RY, Lee J. High-throughput detection of spore contamination in food packages and food powders using tiered approach of ATP bioluminescence and real-time PCR. Lebensm Wiss Technol 2012. [DOI: 10.1016/j.lwt.2011.09.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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13
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qPCR as a powerful tool for microbial food spoilage quantification: Significance for food quality. Trends Food Sci Technol 2011. [DOI: 10.1016/j.tifs.2011.04.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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14
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Burgess SA, Lindsay D, Flint SH. Thermophilic bacilli and their importance in dairy processing. Int J Food Microbiol 2010; 144:215-25. [DOI: 10.1016/j.ijfoodmicro.2010.09.027] [Citation(s) in RCA: 206] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2010] [Revised: 08/15/2010] [Accepted: 09/25/2010] [Indexed: 11/24/2022]
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15
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PCR detection of thermophilic spore-forming bacteria involved in canned food spoilage. Curr Microbiol 2010; 61:525-33. [PMID: 20397018 DOI: 10.1007/s00284-010-9648-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2010] [Accepted: 03/31/2010] [Indexed: 10/19/2022]
Abstract
Thermophilic bacteria that form highly heat-resistant spores constitute an important group of spoilage bacteria of low-acid canned food. A PCR assay was developed in order to rapidly trace these bacteria. Three PCR primer pairs were designed from rRNA gene sequences. These primers were evaluated for the specificity and the sensitivity of detection. Two primer pairs allowed detection at the species level of Geobacillus stearothermophilus and Moorella thermoacetica/thermoautrophica. The other pair allowed group-specific detection of anaerobic thermophilic bacteria of the genera Thermoanaerobacterium, Thermoanaerobacter, Caldanerobium and Caldanaerobacter. After a single enrichment step, these PCR assays allowed the detection of 28 thermophiles from 34 cans of spoiled low-acid food. In addition, 13 ingredients were screened for the presence of these bacteria. This PCR assay serves as a detection method for strains able to spoil low-acid canned food treated at 55°C. It will lead to better reactivity in the canning industry. Raw materials and ingredients might be qualified not only for quantitative spore contamination, but also for qualitative contamination by highly heat-resistant spores.
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Lindström M, Myllykoski J, Sivelä S, Korkeala H. Clostridium botulinumin Cattle and Dairy Products. Crit Rev Food Sci Nutr 2010; 50:281-304. [DOI: 10.1080/10408390802544405] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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17
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Reekmans R, Van den Plas C, Stevens P, Vervust T, De Vos P. An alternative real-time PCR method for the detection of thermotolerant Bacillus sensu lato contaminants in naturally-contaminated gelatine. Lett Appl Microbiol 2009; 48:763-9. [PMID: 19413775 DOI: 10.1111/j.1472-765x.2009.02612.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AIMS Comparison of an internally-controlled real-time PCR assay with the current plate-based assay for the detection of Bacillus sensu lato contaminants in gelatine. METHODS AND RESULTS A comprehensive TaqMan probe was designed allowing the real-time PCR assay to be fully inclusive for the gelatine-contaminating Bacillus s.l. species. An internal amplification control was implemented at 500 copies per reaction without impact on target detection. Specific and selective detection of target cells was achieved with a quick and simple DNA preparation procedure. No significant difference (Kappa value = 0.94) was observed between the performance of the real-time PCR and the current plate-based method on naturally contaminated gelatines (n = 162). Relative accuracy, relative sensitivity and relative specificity were 97.5%. CONCLUSIONS The real-time PCR assay is an adequate alternative of the current plate-based assay. SIGNIFICANCE AND IMPACT OF THE STUDY The real-time PCR assay decreased the time between sample collection and result from 2 days to 2 h. The gelatine-producing industry can ensure gelatine quality in a much faster way.
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Affiliation(s)
- R Reekmans
- Laboratory of Microbiology, Department of Biochemistry and Microbiology, Ghent University, Ghent, Belgium.
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PCR-based method using propidium monoazide to distinguish viable from nonviable Bacillus subtilis spores. Appl Environ Microbiol 2009; 75:2936-9. [PMID: 19270144 DOI: 10.1128/aem.02524-08] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
This paper describes a molecular-based method which is able to discriminate between viable and inactivated Bacillus subtilis spores by utilizing the DNA-intercalating dye propidium monoazide. The approach should be valuable in our attempt to employ molecular methods to streamline the evaluation of process validation using bacterial endospores.
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19
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Ikeno S, Asakawa H, Haruyama T. Molecular Commonality Detection Using an Artificial Enzyme Membrane for in Situ One-Stop Biosurveillance. Anal Chem 2007; 79:5540-6. [PMID: 17616170 DOI: 10.1021/ac0708902] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Biodetection and biosensing have been developed based on the concept of sensitivity toward specific molecules. However, current demand may require more levelheaded or far-sighted methods, especially in the field of biological safety and security. In the fields of hygiene, public safety, and security including fighting bioterrorism, the detection of biological contaminants, e.g., microorganisms, spores, and viruses, is a constant challenge. However, there is as yet no sophisticated method of detecting such contaminants in situ without oversight. The authors focused their attention on diphosphoric acid anhydride, which is a structure common to all biological phosphoric substances. Interestingly, biological phosphoric substances are peculiar substances present in all living things and include many different substances, e.g., ATP, ADP, dNTP, pyrophosphate, and so forth, all of which have a diphosphoric acid anhydride structure. The authors took this common structure as the basis of their development of an artificial enzyme membrane with selectivity for the structure common to all biological phosphoric substances and studied the possibility of its application to in situ biosurveillance sensors. The artificial enzyme membrane-based amperometric biosensor developed by the authors can detect various biological phosphoric substances, because it has a comprehensive molecular selectivity for the structure of these biological phosphoric substances. This in situ detection method of the common diphosphoric acid anhydride structure brings a unique advantage to the fabrication of in situ biosurveillance sensors for monitoring biological contaminants, e.g., microorganism, spores, and viruses, without an oversight, even if they were transformed.
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Affiliation(s)
- Shinya Ikeno
- Department of Biological Functions and Engineering, Kyushu Institute of Technology, Kitakyushu Science and Research Park, Fukuoka, 808-0196, Japan
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Rönner AC, Lindmark H. Quantitative detection of Campylobacter jejuni on fresh chicken carcasses by real-time PCR. J Food Prot 2007; 70:1373-8. [PMID: 17612066 DOI: 10.4315/0362-028x-70.6.1373] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Campylobacter jejuni infection is a significant cause of foodborne gastroenteritis worldwide. Consumption and handling of poultry products is believed to be the primary risk factor for campylobacteriosis. Risk assessments require quantitative data, and C. jejuni is enumerated usually by direct plating, which sometimes allows growth of non-Campylobacter bacteria. The objective of the present study was to develop a quantitative real-time PCR method (q-PCR) for enumerating C. jejuni in chicken rinse without a culturing step. The procedure to obtain the template for the PCR assay involved (i) filtration of 10 ml of chicken rinse, (ii) centrifugation of the sample, and (iii) total DNA extraction from the pellet obtained using a commercial DNA extraction kit. The detection limit of the method was comparable to that for plating 100 microl of chicken rinse on modified charcoal cefoperazone deoxycholate agar, and the detection limit could be further improved 10-fold by concentrating the DNA eluate by ethanol precipitation. A close correlation for spiked chicken rinse was obtained for the results of the quantitative real-time PCR method and direct plating (r = 0.99). The coefficient of correlation for the methods was 0.87 when samples from chicken carcasses on the slaughter line were analyzed, whereas a lower correlation (r = 0.76) was obtained when samples from retail carcasses were analyzed. Greater variation in the proportion of dead and/or viable but not culturable Campylobacter types in the retail samples may explain the decreased correlation between the methods. Overall, the new method is simple and fast and the results obtained are closely correlated with those for direct plating for samples containing a low proportion of dead Campylobacter cells.
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Affiliation(s)
- Anna-Clara Rönner
- Department of Infectious Diseases, Sahlgrenska Academy, University of Gothenburg, Guldhedsg. IOA, SE-413 46 Gothenburg, Sweden
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