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xTAG Luminex multiplex assay for rapid screening of verocytotoxin-producing Escherichia coli strains

Abstract

The O26 verocytotoxin-producing Escherichia coli (VTEC)-associated outbreak of hemolytic uremic syndrome (HUS) cases in Romania during 2016 showed the need to improve the current methodology of non-O157 VTEC detection and surveillance. An in-house assay based on xTAG Luminex technology was optimized to identify seven of the most relevant diarrheagenic E.coli serogroups (O-specific wzx genes), two convenient VTEC virulence markers (eaeA and ehxA genes), and a species-specific control gene (uidA). Twenty-nine strains previously characterized in terms of serogroup and virulence genes were tested with the optimized protocol and the results were as expected. The ratio of sample signal to background varied from 66.7 (ehxA) to 7.6 (uidA) for positive samples, with a cut-off of 3. Sensitivity varied depending on the target to be amplified from approximately 102 genomic copies to approximately 104 genomic copies per reaction, respectively. The current approach seems an affordable alternative to commercially available assays that can be further exploited to improve existing autochthonous strategies to prevent future VTEC outbreaks.

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Serogroups, Virulence Genes and Antibiotic Resistance of Escherichia coli Isolated from Cold Smoked Meat Products and Sprouted Grains in Latvia

. Available from: https://www.efsa.europa.eu (last accessed 2 August 2017). Anonymous (2011b). USDA (Food Safety and Inspection Service). Available from: http://www.fsis.usda.gov/wps/portal/fsis/home (last accessed 2 August 2017). Anonymous (2013a). CLSI (Clinical and Laboratory Standards Institute). Available from: https://clsi.org (last accessed 2 August 2017). Anonymous (2013b). Scientific Opinion on VTEC-seropathotype and scientific criteria regarding pathogenicity assessment. EFSA (European Food Safety Authority) J., 11 (4), 3138

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Comparison of methods for the identification and sub-typing of O157 and non-O157 Escherichia coli serotypes and their integration into a polyphasic taxonomy approach

a polyphasic scheme will probably constitute a precise typing approach that allows better understanding of population structure and taxonomic relationships. Verocytotoxigenic Escherichia coli (VTEC) are zoonotic agents characterised by the production of Shiga-like toxins commonly associated with foodborne disease episodes that can lead to severe health complications and, sometimes, death. Correct VTEC classification and sub-typing is crucial for regulatory authorities and food business operators because false positive claims might be detrimental to business

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The effect of antimicrobials on verocytotoxin bacteriophage transduction under bovine rumen fluid and broth conditions

Introduction Escherichia coli are part of the normal intestinal microflora, although some strains cause diarrhoegenic infections in humans. Enteric E . coli have traditionally been divided into six pathotypes: enteropathogenic E . coli (EPEC), enterotoxigenic E . coli (ETEC), enteroinvasive E . coli (EIEC), verocytotoxigenic E . coli (VTEC), enteroaggregative E . coli (EAEC) and diffusely adherent E . coli (DAEC) ( European Food Safety Authority [EFSA], 2013 ). Two further pathotypes have been proposed by Clements et al . (2012

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Multiplex real-time PCRs for detection of Salmonella, Listeria monocytogenes, and verotoxigenic Escherichia coli in carcasses of slaughtered animals

Abstract

Introduction: The study objective was to develop and evaluate a new TaqMan multiplex real-time PCR method for Salmonella, L. monocytogenes, and verotoxigenic Escherichia coli (VTEC) detection in slaughtered animal carcasses.

Material and Methods: The procedure included an enrichment step, DNA extraction, and two multiplex real-time PCRs. The first PCR detected the invA and hly genes of Salmonella and L. monocytogenes respectively, the second the vtx1, vtx2, and eae genes of VTEC.

Results: The validation of this method resulted in 100% relative sensitivity, specificity, and accuracy as compared to the reference ISO methods. The limit of detection per swab sample was established at 1 cfu for Salmonella and L. monocytogenes and 2 cfu for VTEC. The authors analysed 265 slaughterhouse-collected swabs from cattle, pig, and poultry carcasses. Among 125 from cattle, 51 were positive for VTEC, 29 for Salmonella, and 1 for L. monocytogenes. Among swabs from pig carcasses (n = 95), three, two, and one sample were positive for these pathogens respectively. None of the microorganisms tested for was identified in 45 samples of poultry origin.

Conclusion: The obtained results showed that the method developed can rapidly identify the main bacterial pathogens that may contaminate carcasses of food-producing animals.

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Study of EGNOS safety of life service during the period of solar maximum activity

ABSTRACT

The Satellite Base Augmentation System (SBAS) - EGNOS (European Geostationary Navigation Overlay Service) has been certified for Safety of Life (SoL) service for aircraft navigation since 2nd of March 2011. Unfortunately for the territory of Poland, located at the edge of EGNOS service area, the quality of the service corrections are still not sufficient for aircraft navigation requirements. Years 2012 and 2013 are forecasted as a maximum of solar activity in a 11-year solar cycle. This time period will be the chance to perform the first tests for the EGNOS Safety of Life service quality in disturbed ionospheric conditions. During the previous maximum of solar activity, the storm on 30 October 2003 resulted in the inability to use WAAS corrections for more than 12 hours. This was caused by a very large gradient of disturbances and its’ very sharp boundaries - vertical TEC (VTEC) varied from ~ 40 to ~ 120 TECU (TEC units) within an hour (over ~ 150 km distance). These circumstances gave the opportunity to carry out the test flights to examine the navigation parameters obtained for EGNOS SoL service in disturbed ionospheric conditions. The paper presents project proposal of study and analyses of such fundamental navigation parameters as: accuracy of determined position, availability, continuity and integrity, determined for selected disturbances in relation to quiet conditions. It can give a possibility to estimate of the quality of EGNOS SoL service in Polish airspace during the different phases of flight and its resistance to critical ionospheric conditions.

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Prevalence and some virulence genes of Escherichia coli O157 isolated from chicken meats and giblets

). Investigation of verotoxigenic Escherichia coli O157:H7 incidence in gastroenteritis patients. Mikrobiyol. Bul., 45: 519-525. Eurosurveillance (1999). Sporadic cases of VTEC O157 infection associated with travel to southern Turkey, 3: 443-446. Available online: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=1288 Fields P.I., Blom K., Hughes H.J., Helsel L.O., Feng P., Swaminathan B. (1997). Molecular characterization of the gene encoding Hantigen in Escherichia coli and development ofa PCR-restriction fragment length polymorphism

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Comparative Analysis of Future Cooks’ Training in Vocational Institutions in Ukraine and Abroad

-5122-NO.55.3.5-2007 for Training Cooks of Categories 3–6]. Retrieved 19.02.2017 from : http://www.vtec.vn.ua/sites/default/files/page/files/kuhar.pdf . 14. Мумрикова, Г. (2001). Увидеть Париж и… поучиться? [See Paris and ... Learn]. Питание и общество [Nutrition and Society], No 4, pp.15–16 (in Russian). 15. Национальный правовой Интернет-портал Республики Беларусь [National Legal Portal of the Republic of Belarus]. (2016). Образовательный стандарт профессионально-технического образования Республики Беларусь по специальности 3-91 01 51 «Общественное

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Nequick2 Model Behaviour for Global Ionospheric Delay Mitigation During Solar Cycle-24

References Di Giovanni, G. and S. R. Radicella (1990). An Analytical model of the electron density profile in the ionosphere. Advanced Space Research, 10, No.11, 27-30. Ezquer R.G., L.A. Scidá, Y. Migoya Orué, B. Nava, M.A. Cabrera, C. Brunini (2018). NeQuick 2 and IRI Plas VTEC predictions for low latitude and South American sector. Advances in Space Research, Volume 61, Issue 7, Pages 1803-1818. Hochegger, G., Nava, B., Radicella, S.M., Leitinger, R., (2000). A family of ionospheric models for different uses

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Investigations on Prevalence and Antimicrobial Resistance of Enterohaemorrhagic Escherichia Coli (Ehec) Among Dairy Farms in the North Part of the Republic of Bulgaria

vaccines for terrestrial animals. Paris: OIE; Verocytotoxigenic Escherichia coli. 15. Europian Food Safety (EFSA). (2007). Monitoring of Verotoxigenic Escherichia coli (VTEC) and identification of human pathogenic VTEC types. Scientific Opinion of the Panel on Bilogical Hazards. EFSA J. 579, 1-61. 16. Hussein, H. S., Bollinger, L. M. (2005). Prevalence of Shiga toxin-producing E. coli in beef cattle. J.Food Prot. 68, 2224-2241. PMid:16245735 17. Europian Food Safety (EFSA) Scientific Report of EFSA (2009). Technical

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