DOCSLIB.ORG

Cellular Injuries in Cronobacter Sakazakii CIP 103183T And

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Cellular Injuries in Cronobacter Sakazakii CIP 103183T And Cellular Injuries in Cronobacter sakazakii CIP 103183T and Salmonella enterica Exposed to Drying and Subsequent Heat Treatment in Milk Powder Emilie Lang, Stéphane Guyot, Caroline Peltier, Pablo Alvarez-Martin, Jean-Marie Perrier-Cornet, Patrick Gervais To cite this version: Emilie Lang, Stéphane Guyot, Caroline Peltier, Pablo Alvarez-Martin, Jean-Marie Perrier-Cornet, et al.. Cellular Injuries in Cronobacter sakazakii CIP 103183T and Salmonella enterica Exposed to Drying and Subsequent Heat Treatment in Milk Powder. Frontiers in Microbiology, Frontiers Media, 2018, 9, pp.475. 10.3389/fmicb.2018.00475. hal-01907589 HAL Id: hal-01907589 https://hal-univ-bourgogne.archives-ouvertes.fr/hal-01907589 Submitted on 26 May 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Distributed under a Creative Commons Attribution| 4.0 International License fmicb-09-00475 March 9, 2018 Time: 17:6 # 1 ORIGINAL RESEARCH published: 13 March 2018 doi: 10.3389/fmicb.2018.00475 Cellular Injuries in Cronobacter sakazakii CIP 103183T and Salmonella enterica Exposed to Drying and Subsequent Heat Treatment in Milk Powder Emilie Lang1,2, Stéphane Guyot1, Caroline Peltier1, Pablo Alvarez-Martin2, Jean-Marie Perrier-Cornet1 and Patrick Gervais1* 1 UMR PAM A 02.102 Procédés Alimentaires et Microbiologiques, Université de Bourgogne Franche-Comté/AgroSup Dijon, Dijon, France, 2 Novolyze, Daix, France Because of the ability of foodborne pathogens to survive in low-moisture foods, their Edited by: decontamination is an important issue in food protection. This study aimed to clarify Avelino Alvarez-Ordóñez, some of the cellular mechanisms involved in inactivation of foodborne pathogens Universidad de León, Spain after drying and subsequent heating. Individual strains of Salmonella Typhimurium, Reviewed by: Salmonella Senftenberg, and Cronobacter sakazakii were mixed into whole milk powder Zhao Chen, University of California, Davis, and dried to different water activity levels (0.25 and 0.58); the number of surviving cells United States was determined after drying and subsequent thermal treatments in closed vessels at Rabindra Kumar Mandal, ◦ University of Louisville, United States 90 and 100 C, for 30 and 120 s. For each condition, the percentage of unculturable *Correspondence: cells was estimated and, in parallel, membrane permeability and respiratory activity Patrick Gervais were estimated by flow cytometry using fluorescent probes. After drying, it was clearly [email protected] observable that the percentage of unculturable cells was correlated with the percentage Specialty section: of permeabilized cells (responsible for 20–40% of the total inactivated bacteria after This article was submitted to drying), and to a lesser degree with the percentage of cells presenting with loss Food Microbiology, of respiratory activity. In contrast, the percentages of unculturable cells observed a section of the journal Frontiers in Microbiology after heat treatment were strongly correlated with the loss of respiratory activity and Received: 09 October 2017 weakly with membrane permeability (for 70–80% of the total inactivated bacteria after Accepted: 28 February 2018 heat treatment). We conclude that cell inactivation during drying is closely linked to Published: 13 March 2018 membrane permeabilization and that heat treatment of dried cells affects principally Citation: Lang E, Guyot S, Peltier C, their respiratory activity. These results legitimize the use of time–temperature scales and Alvarez - Martin P, Perrier-Cornet J-M allow better understanding of the cellular mechanisms of bacterial death during drying and Gervais P (2018) Cellular Injuries and subsequent heat treatment. These results may also allow better optimization of in Cronobacter sakazakii CIP 103183T and Salmonella enterica the decontamination process to ensure food safety by targeting the most deleterious Exposed to Drying and Subsequent conditions for bacterial cells without denaturing the food product. Heat Treatment in Milk Powder. Front. Microbiol. 9:475. Keywords: Salmonella enterica, Cronobacter sakazakii, membrane permeability, respiratory activity, doi: 10.3389/fmicb.2018.00475 heat treatment, drying Frontiers in Microbiology| www.frontiersin.org 1 March 2018| Volume 9| Article 475 fmicb-09-00475 March 9, 2018 Time: 17:6 # 2 Lang et al. Causes of Bacterial Inactivation in Dried State INTRODUCTION In addition, drying increases the thermal resistance of several foodborne pathogens, including S. enterica or C. sakazakii, Salmonella enterica and Cronobacter sakazakii are Gram- because of the production heat-shock proteins (HSP) during negative, facultative anaerobic, motile, nonspore-forming drying (Potts, 2001; Dancer et al., 2009; Li et al., 2012). bacteria that cause human disease (Beuchat et al., 2013). They Heat is a classical and effective means to reduce are of major concern in the infant-food industry (Podolak et al., microbiological load in food and is widely used in food industry 2010), because ingestion of very few (10–100) S. enterica cells (Lee et al., 1989). In liquid media, it has been well-managed by young children causes severe illness (Rotger and Casadesús, for many years; processes such as pasteurization or sterilization 1999), and C. sakazakii can cause severe infections such as are optimized and the mechanisms of bacterial inactivation in meningitis, bacteremia, and necrotizing enterocolitis in infants, liquid media are well-understood. For Gram negative bacteria, with a death rate up to 80% and an infectious dose estimated 103 heat treatment in liquid media is known to disrupt the outer cells (Friedemann, 2008; Strydom et al., 2012). membrane, resulting in irreversible damages (Chang et al., 2009). Foodborne pathogens encounter many stresses in food The inner membrane is also sensitive to thermal treatment, and processing environments and food products (Wesche et al., heating causes perturbation of the biochemical functions of the 2009). Drying, which occurs during the production of membrane that are deleterious for bacterial cell (Russell, 2003; low-moisture foods, is one of these stresses. It consists of a Guyot et al., 2010). Proteins are also denatured by heat treatment, diminution of water activity (aw), which represents the available which causes disruption of hydrogen and disulfide bonds and water for chemical and biochemical reactions (Iaconelli et al., consequently the loss of protein function (Russell, 2003). These 2015). During desiccation, water evaporation involves two main two mechanisms are involved in bacterial cells death during heat cellular stresses (Billi and Potts, 2002). The first corresponds to treatment in liquid media and result in a large scale inactivation an increase in solute concentration and the osmotic pressure in of bacterial population. In contrast, the impact of heat treatment the external environment, which induces a water release from on dried foods is not well-known, and clarifying this will allow the cell (Billi and Potts, 2002; Dupont et al., 2014). The second the optimization of heat treatment to preserve food qualities such corresponds to complete water evaporation, where bacteria in a as aroma, color, or vitamins, while assuring food safety. Public dried state undergo an oxidative stress because of exposure to opinion easily accepts heat treatment, in contrast to acceptance atmospheric oxygen (Billi and Potts, 2002; Dupont et al., 2014). of other types of treatment such as irradiation (Kume et al., Bacteria have several active or passive mechanisms to resist 2009), and a better understanding of the mechanisms involved osmotic stress, which enhance their survival and acclimation. could lead to the establishment of optimal heating conditions by The passive mechanisms, resulting from water outflow, involve identification of the treatment parameters such as temperature molecular desiccation by refolding of molecules such as enzymes that are most deleterious for bacterial cells. to protect them from active site alteration (Parsegian et al., 1995). In this study, we investigated the impact of drying and They also involve a membrane phase transition from liquid to subsequent heat treatment on the membrane integrity and gel phase. The active mechanisms, which occur in the range respiratory activity of C. sakazakii, S. enterica subsp. enterica of physiological aw (between aw of 0.999 and approximately serovar Typhimurium and serovar Senftenberg in milk powder. 0.940, depending on the bacterial species), involve accumulation Propidium iodide (PI) and 5-cyano-2,3-ditolyl tetrazolium of ions and counterions inside the cell that reduce water loss chloride were used in this study to assess the membrane integrity before another response that permits the synthesis of compatible and the respiratory activity, respectively, permitting to visualize solutes, for example, trehalose for S. enterica (Rychlik and the impact of technological stresses on bacterial structure and Barrow, 2005; Spector and Kenyon, 2012). functionality. Drying was performed to two
Load more

Recommended publications
  • Taqman® Cronobacter Sakazakii Detection
    Applied Biosystems Food Pathogen Detection System TaqMan ® Cronobacter sakazakii Detection Kit Simple, reliable, and rapid detection TaqMan® Pathogen Detection Kits • Cronobacter sakazakii • Salmonella enterica • Campylobacter jejuni • E. coli O157:H7 • Listeria monocytogenes • Pseudomonas aeruginosa • Staphylococcus aureus An Infant Formula Contaminant Real-Time PCR Delivers Detect E. sakazakii Faster Cronobacter sakazakii is a pathogen The TaqMan Cronobacter sakazakii A number of tests are currently mostly associated with powdered Detection Kit uses proven real-time available that identify Cronobacter infant formula, causing seizures, brain PCR technology designed to provide: sakazakii based on phenotypic and abscesses, developmental delay, and biochemical methods. However, • Highly selective identification of even death in infants with premature because of isolates that may escape Cronobacter sakazakii in a wide variety infants and newborns at greatest risk. identification with these methods, faster, of food and finished product samples It is therefore extremely important more reliable methods are needed. that infant formula be tested prior to • Verified performance The TaqMan® Cronobacter sakazakii release to the marketplace. It is currently Detection Kit offers such an alternative. • Ready-to-use convenience unknown how many organisms will cause infection, thus a highly specific • Reduced risk of contamination product testing method is necessary to determine the presence of Cronobacter sakazakii. Rely on Applied Biosystems Use a Complete
    [Show full text]
  • Infant and New Mother
    Infant and New Mother Product Category: Infant and New Mother EleCare® Similac Expert Care® 24 Cal With Iron EleCare® (for Infants) Similac Expert Care® Alimentum® Similac Expert Care® for Diarrhea Similac Expert Care® NeoSure® Metabolic Similac For Spit-Up® Calcilo XD® Similac Go & Grow® Milk-Based Formula Cyclinex®-1 Similac Go & Grow® Soy-Based Formula Glutarex®-1 Similac Sensitive® Hominex®-1 Similac Total Comfort™ I-Valex®-1 Similac® 10-pct Glucose Water Ketonex®-1 Similac® 5-pct Glucose Water Phenex™-1 Similac® Advance® Pro-Phree® Similac® Advance® Organic Propimex®-1 Similac® For Supplementation ProViMin® Similac® Human Milk Fortifier RCF® Similac® Human Milk Fortifier Concentrated Liquid Tyrex®-1 Similac® Nipples Similac® PM 60/40 Pedialyte® Similac® Prenatal & Breastfeeding Dietary Supplement Pedialyte AdvancedCare™ Pedialyte® Liters Similac® Simply Smart™ Similac® Soy Isomil® Similac® Similac® Sterilized Water Similac® Volu-Feed® Bottles & Caps Liquid Protein Fortifier For more information, contact your Abbott Nutrition Representative or visit www.abbottnutrition.com Abbott Nutrition Abbott Laboratories © 2013 Abbott Laboratories Inc. Columbus, OH 43219-3034 Updated 11/18/2013 1-800-227-5767 EleCare® Product Category: EleCare® EleCare® (for Infants) For more information, contact your Abbott Nutrition Representative or visit www.abbottnutrition.com Abbott Nutrition Abbott Laboratories © 2013 Abbott Laboratories Inc. Columbus, OH 43219-3034 Updated 11/18/2013 1-800-227-5767 EleCare® (for Infants) Nutritionally Complete Amino Acid-Based Infant Formula with Iron Product Information: EleCare® (for Infants) For more information, contact your Abbott Nutrition Representative or visit www.abbottnutrition.com Abbott Nutrition Abbott Laboratories © 2013 Abbott Laboratories Inc. Columbus, OH 43219-3034 Updated 1/1/0001 1-800-227-5767 1 of 5 EleCare® (for Infants) Nutritionally Complete Amino Acid-Based Infant Formula with Iron l EleCare is a nutritionally complete amino-acid based formula for infants who cannot tolerate intact or hydrolyzed protein.
    [Show full text]
  • International Journal of Systematic and Evolutionary Microbiology (2016), 66, 5575–5599 DOI 10.1099/Ijsem.0.001485
    International Journal of Systematic and Evolutionary Microbiology (2016), 66, 5575–5599 DOI 10.1099/ijsem.0.001485 Genome-based phylogeny and taxonomy of the ‘Enterobacteriales’: proposal for Enterobacterales ord. nov. divided into the families Enterobacteriaceae, Erwiniaceae fam. nov., Pectobacteriaceae fam. nov., Yersiniaceae fam. nov., Hafniaceae fam. nov., Morganellaceae fam. nov., and Budviciaceae fam. nov. Mobolaji Adeolu,† Seema Alnajar,† Sohail Naushad and Radhey S. Gupta Correspondence Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Radhey S. Gupta L8N 3Z5, Canada [email protected] Understanding of the phylogeny and interrelationships of the genera within the order ‘Enterobacteriales’ has proven difficult using the 16S rRNA gene and other single-gene or limited multi-gene approaches. In this work, we have completed comprehensive comparative genomic analyses of the members of the order ‘Enterobacteriales’ which includes phylogenetic reconstructions based on 1548 core proteins, 53 ribosomal proteins and four multilocus sequence analysis proteins, as well as examining the overall genome similarity amongst the members of this order. The results of these analyses all support the existence of seven distinct monophyletic groups of genera within the order ‘Enterobacteriales’. In parallel, our analyses of protein sequences from the ‘Enterobacteriales’ genomes have identified numerous molecular characteristics in the forms of conserved signature insertions/deletions, which are specifically shared by the members of the identified clades and independently support their monophyly and distinctness. Many of these groupings, either in part or in whole, have been recognized in previous evolutionary studies, but have not been consistently resolved as monophyletic entities in 16S rRNA gene trees. The work presented here represents the first comprehensive, genome- scale taxonomic analysis of the entirety of the order ‘Enterobacteriales’.
    [Show full text]
  • Enterobacter Sakazakii)
    International Journal of Food Microbiology 136 (2009) 159–164 Contents lists available at ScienceDirect International Journal of Food Microbiology journal homepage: www.elsevier.com/locate/ijfoodmicro Microarray-based comparative genomic indexing of the Cronobacter genus (Enterobacter sakazakii) B. Healy a, S. Huynh b, N. Mullane a, S. O'Brien a, C. Iversen a, A. Lehner c, R. Stephan c, C.T. Parker b,⁎, S. Fanning a,⁎ a Centres for Food Safety and Food-borne Zoonomics, UCD Veterinary Sciences Centre, University College Dublin, Belfield, Dublin 4, Ireland b Produce Safety and Microbiology Research Unit, Agricultural Research Service, U.S. Department of Agriculture, 800 Buchanan Street, Albany, CA 94710, USA c Institute for Food Hygiene and Safety, VetSuisse Faculty, University of Zurich, Zurich CH-, Switzerland article info abstract Keywords: Cronobacter (Enterobacter sakazakii) is a recently defined genus consisting of 6 species. To extend our Microarray understanding of the genetic relationship between Cronobacter sakazakii BAA-894 and the other species of Comparative this genus, microarray-based comparative genomic indexing (CGI) was undertaken to determine the Genome presence/absence of genes identified in the former sequenced genome and to compare 276 selected open Cronobacter reading frames within the different Cronobacter strains. Seventy-eight Cronobacter strains (60 C. sakazakii, Enterobacter sakazakii 8 C. malonaticus,5C. dublinensis,2C. muytjensii,1C. turicensis,1C. genomospecies 1, and 1 Cronobacter sp.) representing clinical and environmental isolates from various geographical locations were investigated. Hierarchical clustering of the CGI data showed that the species grouped as clusters. The 5 C. dublinensis and 2 C. muytjensii strains examined formed distinct species clusters.
    [Show full text]
  • Green Feeding – Climate Action from Birth
    Geneva, Nov 6, 2019 Green Feeding – climate action from birth Summary In this advocacy document the authors aim to show how the subject of Green Feeding of infants and young children can support the growing worldwide movement for climate action by school children, parents and the public. At the same time, we aim to further the policy initiatives of Green parties and political parties with green priorities. Part I defines Green Feeding and provides the rationale for the inclusion of Green Feeding in policies and programmes. Part II provides examples of specific actions to be taken at individual, community, regional and country levels, presented as separate modules that can be selected according to priorities1. Part III suggests how these actions can build on the results of national assessments in the World Breastfeeding Trends initiative (WBTi) and provides information on the WBTi participatory process. What is Green Feeding ?2 Green Feeding describes optimal and sustainable breastfeeding and complementary feeding practices for infants and young children aged from 0-36 months. Such optimal infant and young child feeding practices protect the health of infants, young children and their mothers, as well as the environment of our planet – Mother Earth. Often people feel that climate change caused by global warming is such an immense problem that there is nothing that individuals can do about it. But each and every one of us was nurtured as a baby by being fed breastmilk or with a substitute based on cow’s milk. Everyone can thus relate to infant and young child feeding practices - and can learn how to make these practices environmentally friendly.
    [Show full text]
  • Shiga Toxin-Producing Escherichia Coli (STEC) and Food: Attribution, Characterization, and Monitoring
    31 ISSN 1726-5274 Shiga toxin-producing Escherichia coli (STEC) infections are a substantial health issue worldwide. Circa 2010, foodborne STEC caused > 1 million human illnesses, 128 deaths, and ~ 13,000 Disability Adjusted Life Years (DALYs). Targeting interventions to address this hazard relies on identifying those STEC strains of greatest risk to human health and determining the food vehicles for such infections. This report brings together the review and analysis of existing information on the burden, source attribution, hazard characterization and monitoring of STEC. It proposes a set of criteria for categorizing the potential risk of severity of characterisation, and monitoring Shiga toxin-producing illness associated with the presence of a STEC in food, for consideration by risk managers, as part of a risk-based approach to control STEC in foods. It presents the initial results on source attribution of foodborne STEC, highlighting that while ruminants and other land animals are considered the main reservoirs Shiga toxin-producing for STEC, largescale outbreaks have also been linked to other foods, such as fresh produce. It also provides a review of monitoring programmes and meth- odology for STEC, which can serve as a reference for countries planning to Escherichia coli (STEC) develop such programmes. Escherichia coli ( and food: attribution, This work was undertaken in response to a request from the Codex Alimentarius to support the development of international standards on foodborne STEC. The advice herein is useful for both
    [Show full text]
  • Cronobacter: an Emerging Opportunistic Pathogen Associated with Neonatal Meningitis, Sepsis and Necrotizing Enterocolitis
    Journal of Perinatology (2013) 33, 581–585 & 2013 Nature America, Inc. All rights reserved 0743-8346/13 www.nature.com/jp STATE-OF-THE-ART Cronobacter: an emerging opportunistic pathogen associated with neonatal meningitis, sepsis and necrotizing enterocolitis CJ Hunter1,2 and JF Bean1 Members of the genus Cronobacter are an emerging group of opportunist Gram-negative pathogens. This genus was previously thought to be a single species, called Enterobacter sakazakii. Cronobacter spp. typically affect low-birth-weight neonates, causing life-threatening meningitis, sepsis and necrotizing enterocolitis. Outbreaks of disease have been associated with contaminated infant formula, although the primary environmental source remains elusive. Advanced understanding of these bacteria and better classification has been obtained by improved detection techniques and genomic analysis. Research has begun to characterize the virulence factors and pathogenic potential of Cronobacter. Investigations into sterilization techniques and protocols for minimizing the risk of contamination have been reviewed at national and international forums. In this review, we explore the clinical impact of Cronobacter neonatal and pediatric infections, discuss virulence and pathogenesis, and review prevention and treatment strategies. Journal of Perinatology (2013) 33, 581–585; doi:10.1038/jp.2013.26; published online 28 March 2013 Keywords: Cronobacter sakazakii; meningitis; necrotizing enterocolitis; neonatal infections; infant formula INTRODUCTION single clinical setting.10 Cronobacter neonatal infection rates Cronobacter is an emerging genus of opportunistic Gram-negative remain low and are reported in the USA as one Cronobacter pathogens associated with potentially fatal neonatal infections, infection per 100 000 infants, 8.7 per 100 000 low-birth-weight including meningitis, sepsis and necrotizing enterocolitis (NEC).1 neonates, and one Cronobacter infection per 10 660 very low- 13 These infections typically affect our smallest and most vulnerable birth-weight neonates.
    [Show full text]
  • Antimicrobial Activities of Medium-Chain Fatty Acids and Monoacylglycerols on Cronobacter Sakazakii DBM 3157T and Cronobacter Malonaticus DBM 3148
    Czech J. Food Sci. Vol. 30, 2012, No. 6: 573–580 Antimicrobial Activities of Medium-chain Fatty Acids and Monoacylglycerols on Cronobacter sakazakii DBM 3157T and Cronobacter malonaticus DBM 3148 Milan MAROUNEK1, Vannaphone PUTTHANA2, Oldřich BENADA3,4 and Daniela LUkešOVÁ2 1Institute of Animal Physiology and Genetics and 3Institute of Microbiology, Czech Academy of Sciences, Prague, Czech Republic; 2Institute of Tropics and Subtropics, Czech University of Life Sciences Prague, Prague, Czech Republic; 4Department of Biology, Faculty of Science, J.E. Purkinje University in Usti nad Labem, Ústí nad Labem, Czech Republic Abstract Marounek M., Putthana V., Benada O., Lukešová D. (2012): Antimicrobial activities of medium- chain fatty acids and monoacylglycerols on Cronobacter sakazakii DBM 3157T and Cronobacter malonaticus DBM 3148. Czech J. Food Sci., 30: 573–580. Cronobacter sakazakii and Cronobacter malonaticus are pathogens causing infections in children that are primarily linked to the consumption of contaminated infant milk formula and food. Both Cronobacter strains examined were susceptible to caprylic acid, monocaprylin and, to a lesser extent, sorbic acid. Capric acid, lauric acid, monosorbin, monocaprin, monolaurin, and sucrose caprate exhibited no inhibitory activity. Caprylic acid and monocaprylin treat- ment (2 mg/ml) of C. sakazakii DBM 3157T reduced the number of viable cells by five orders of magnitude. In the case of C. malonaticus DBM 3148, both caprylic acid and monocaprylin (2 mg/ml) decreased the viable cell counts below the limits of detection. The bactericidal activity of monocaprylin increased as a function of concentration (0.5–2.0 mg/ml) and temperature (40–55°C). The exposure of each Cronobacter strain to monocaprylin resulted in the release of cellular proteins and nucleic acids.
    [Show full text]
  • Pan-Genome Analysis of the Emerging Foodborne Pathogen Cronobacter Spp
    Pan-genome analysis of the emerging foodborne pathogen Cronobacter spp. suggests a species-level bidirectional divergence driven by niche adaptation Grim, C. J., Kotewicz, M. L., Power, K. A., Gopinath, G., Franco, A. A., Jarvis, K. G., Yan, Q. Q., Jackson, S. A., Sathyamoorthy, V., Hu, L., Pagotto, F., Iversen, C., Lehner, A., Stephan, R., Fanning, S., & Tall, B. D. (2013). Pan-genome analysis of the emerging foodborne pathogen Cronobacter spp. suggests a species-level bidirectional divergence driven by niche adaptation. BMC Genomics, 14, [366]. https://doi.org/10.1186/1471- 2164-14-366 Published in: BMC Genomics Document Version: Publisher's PDF, also known as Version of record Queen's University Belfast - Research Portal: Link to publication record in Queen's University Belfast Research Portal Publisher rights © 2013 Grim et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. General rights Copyright for the publications made accessible via the Queen's University Belfast Research Portal is retained by the author(s) and / or other copyright owners and it is a condition of accessing these publications that users recognise and abide by the legal requirements associated with these rights. Take down policy The Research Portal is Queen's institutional repository that provides access to Queen's research output. Every effort has been made to ensure that content in the Research Portal does not infringe any person's rights, or applicable UK laws.
    [Show full text]
  • Taqman® Campylobacter Jejuni Detection
    Applied Biosystems Food Pathogen Detection System TaqMan ® Campylobacter jejuni Detection Kit Fast, easy, accurate detection TaqMan® Pathogen Detection Kits • Campylobacter jejuni • Cronobacter sakazakii • E. coli O157:H7 • Listeria monocytogenes • Pseudomonas aeruginosa • Salmonella enterica • Staphylococcus aureus A Growing Demand Real-Time PCR Delivers Faster Time to Result Campylobacter jejuni and Campylobacter The TaqMan Campylobacter jejuni Traditional Campylobacter jejuni coli cause more cases of bacteria Detection Kit uses Real-Time PCR detection methods can take up to 6 diarrheal illness than Shigella and technology designed to provide: days; immunoassay methods can Salmonella combined. However, strains take 2 days or more. After a 24 hour • Faster time to results are difficult to cultivate and low levels pre-enrichment step, time to result may go undetected using selective • Excellent specificity and sensitivity with the TaqMan Campylobacter jejuni enrichment. This has created a demand Detection Kit is less than 4 hours and • Exceptional ease of use for a rapid C. jejuni test method that less than 28 hours total. does not require isolation and culture. • Reduced risk of contamination Exceptional Ease of Use • Campylobacter jejuni 1 Results in three easy steps • Three easy steps (p/n 4366098) 1. Enrich samples • Software-guided assay procedure • Salmonella enterica 1 Certified by AOAC and AFNOR • No electrophoresis or post-PCR (p/n 4366104) processing • Cronobacter sakazakii 2 The TaqMan Campylobacter jejuni (p/n 4382492) Detection Kit gives you reliable results in just 3 simple steps. RapidFinder™ • E. coli O157:H7 1 2. Prepare samples software guides you through the assay (p/n 4366100) procedure, and displays results on an • Listeria monocytogenes 1 easy-to-read screen for fast, accurate (p/n 4366102) interpretation.
    [Show full text]
  • Taqman® E.Coli O157:H7 Detection
    Applied Biosystems Food Pathogen Detection System TaqMan ® E.coli O157:H7 Detection Kit A simple, reliable, and rapid procedure TaqMan® Pathogen Detection Kits • E. coli O157:H7 • Campylobacter jejuni • Cronobacter sakazakii • Listeria monocytogenes • Pseudomonas aeruginosa • Salmonella enterica • Staphylococcus aureus When Time is of the Essence A Proven Alternative Up to Four Times as Fast Escherichia coli O157:H7, one of over The TaqMan E. coli O157:H7 Detection Traditional E. coli O157:H7 detection 700 reported pathogenic serotypes Kit uses Real-Time PCR technology methods can take up to 7 days; of E. coli, is the causative agent of designed to provide: immunoassay methods can take up to hemorrhagic colitis. Culture-based 4 days. Time to result with the TaqMan • Faster time to results testing for E. coli O157:H7 is time- and E. coli O157:H7 Detection Kit is less than labor- intensive. Selective detection of • Excellent specificity and sensitivity 4 hours after pre-enrichment and less E. coli O157:H7 can also be difficult, than 20 hours total. • Exceptional ease-of-use because it is often found in lower abundance than other pathogens. • Reduced risk of contamination Exceptional Ease of Use • E. coli O157:H71 Results in three easy steps • Three easy steps (p/n 4366100) 1. Enrich samples • Software-guided assay procedure • Salmonella enterica1 Certified by AOAC and AFNOR • No electrophoresis or post-PCR (p/n 4366104) processing • Campylobacter jejuni 1 The TaqMan E. coli O157:H7 Detection (p/n 4366098) Kit gives you reliable results in just three simple steps. RapidFinder™ software • Cronobacter sakazakii 2 2.
    [Show full text]
  • Escherichia Coli
    ARTICLE https://doi.org/10.1038/s41467-020-15350-5 OPEN An acid-tolerance response system protecting exponentially growing Escherichia coli Ying Xu 1,2,8, Zhe Zhao 1,2,8, Wenhua Tong 1,7, Yamei Ding 3, Bin Liu4, Yixin Shi5, Jichao Wang 1, ✉ ✉ Shenmei Sun1,2, Min Liu 1, Yuhui Wang4, Qingsheng Qi6, Mo Xian1 & Guang Zhao 1,6 The ability to grow at moderate acidic conditions (pH 4.0–5.0) is important to Escherichia coli colonization of the host’s intestine. Several regulatory systems are known to control acid 1234567890():,; resistance in E. coli, enabling the bacteria to survive under acidic conditions without growth. Here, we characterize an acid-tolerance response (ATR) system and its regulatory circuit, required for E. coli exponential growth at pH 4.2. A two-component system CpxRA directly senses acidification through protonation of CpxA periplasmic histidine residues, and upre- gulates the fabA and fabB genes, leading to increased production of unsaturated fatty acids. Changes in lipid composition decrease membrane fluidity, F0F1-ATPase activity, and improve intracellular pH homeostasis. The ATR system is important for E. coli survival in the mouse intestine and for production of higher level of 3-hydroxypropionate during fermentation. Furthermore, this ATR system appears to be conserved in other Gram-negative bacteria. 1 CAS Key Lab of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101 Qingdao, China. 2 University of Chinese Academy of Sciences, 100049 Beijing, China. 3 Institute of Oceanology, Chinese Academy of Sciences, 266071 Qingdao, China. 4 TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, 300457 Tianjin, China.
    [Show full text]