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1.
Pharm Res ; 32(7): 2173-9, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25585954

RESUMEN

The worldwide antibiotic crisis has led to a renewed interest in phage therapy. Since time immemorial phages control bacterial populations on Earth. Potent lytic phages against bacterial pathogens can be isolated from the environment or selected from a collection in a matter of days. In addition, phages have the capacity to rapidly overcome bacterial resistances, which will inevitably emerge. To maximally exploit these advantage phages have over conventional drugs such as antibiotics, it is important that sustainable phage products are not submitted to the conventional long medicinal product development and licensing pathway. There is a need for an adapted framework, including realistic production and quality and safety requirements, that allows a timely supplying of phage therapy products for 'personalized therapy' or for public health or medical emergencies. This paper enumerates all phage therapy product related quality and safety risks known to the authors, as well as the tests that can be performed to minimize these risks, only to the extent needed to protect the patients and to allow and advance responsible phage therapy and research.


Asunto(s)
Infecciones Bacterianas , Bacteriófagos/crecimiento & desarrollo , Terapia Biológica , Farmacorresistencia Bacteriana Múltiple , Infecciones Bacterianas/microbiología , Infecciones Bacterianas/terapia , Bacteriófagos/aislamiento & purificación , Terapia Biológica/efectos adversos , Terapia Biológica/normas , Terapia Biológica/tendencias , Humanos
2.
J Clin Virol ; 152: 105191, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35640400

RESUMEN

OBJECTIVES: The aim of this study was to develop a RT-PCR assay for the specific detection of the SARS-CoV-2 Omicron Variant of Concern (VOC) as a rapid alternative to sequencing. METHODS: A RT-PCR was designed in silico and then validated using characterised clinical samples containing Omicron (both BA.1 and BA.2 lineages) and the Omicron synthetic RNA genome. As negative controls, SARS-CoV-2 positive clinical samples collected in May 2020, and synthetic RNA genomes of the isolate Wuhan Hu-1 and of the Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), Kappa (B.1.617.1), Iota (B.1.526), Epsilon (B.1.429) and Delta (B.1.617.2) SARS-CoV-2 VOC were used. RESULTS: Experiments performed using as templates the synthetic RNA genomes demonstrate the high specificity of the PCR-method for the SARS-CoV-2 Omicron. Despite the synthetic RNAs were used at high copy numbers, specific signal was mainly detected with the Omicron synthetic genome. Only a non-specific late signal was detected using the Alpha variant genome, but these results were considered negligible as Alpha VOC has been replaced by the Delta and it is not circulating anymore in the world. Using our method, we confirmed the presence of Omicron on clinical samples containing this variant but not of other SARS-CoV-2 lineages. The method is highly sensitive and can detect up to 1 cp of the Omicron virus per µl. CONCLUSIONS: The method presented here, in combination with other methods in use for detection of SARS-CoV-2, can be used for an early identification of Omicron.


Asunto(s)
COVID-19 , SARS-CoV-2 , COVID-19/diagnóstico , Humanos , ARN Viral/análisis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , SARS-CoV-2/genética , Sensibilidad y Especificidad
3.
Appl Environ Microbiol ; 77(19): 6954-63, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21856838

RESUMEN

European Commission regulation 2073/2005 on the microbiological criteria for food requires that Escherichia coli is monitored as an indicator of hygienic conditions. Since verocytotoxigenic E. coli (VTEC) strains often cause food-borne infections by the consumption of raw food, the Biological Hazards (BIOHAZ) panel of the European Food Safety Authority (EFSA) recommended their monitoring in food as well. In particular, VTEC strains belonging to serogroups such as O26, O103, O111, O145, and O157 are known causative agents of several human outbreaks. Eight real-time PCR methods for the detection of E. coli toxin genes and their variants (stx(1), stx(2)), the intimin gene (eae), and five serogroup-specific genes have been proposed by the European Reference Laboratory for VTEC (EURL-VTEC) as a technical specification to the European Normalization Committee (CEN TC275/WG6). Here we applied a "modular approach" to the in-house validation of these PCR methods. The modular approach subdivides an analytical process into separate parts called "modules," which are independently validated based on method performance criteria for a limited set of critical parameters. For the VTEC real-time PCR module, the following parameters are being assessed: specificity, dynamic range, PCR efficiency, and limit of detection (LOD). This study describes the modular approach for the validation of PCR methods to be used in food microbiology, using single-target plasmids as positive controls and showing their applicability with food matrices.


Asunto(s)
Técnicas Bacteriológicas/métodos , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Escherichia coli Shiga-Toxigénica/clasificación , Escherichia coli Shiga-Toxigénica/aislamiento & purificación , Infecciones por Escherichia coli/prevención & control , Microbiología de Alimentos , Humanos , Sensibilidad y Especificidad , Escherichia coli Shiga-Toxigénica/genética
4.
F1000Res ; 10: 550, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-35106136

RESUMEN

Background: SARS-CoV-2 that causes COVID-19 disease and led to the pandemic currently affecting the world has been broadly investigated. Different studies have been performed to understand the infection mechanism, and the involved human genes, transcripts and proteins. In parallel, numerous clinical extra-pulmonary manifestations co-occurring with COVID-19 disease have been reported and evidence of their severity and persistence is increasing. Whether these manifestations are linked to other disorders co-occurring with SARS-CoV-2 infection, is under discussion. In this work, we report the identification of toxin-like peptides in COVID-19 patients by application of the Liquid Chromatography Surface-Activated Chemical Ionization - Cloud Ion Mobility Mass Spectrometry.   Methods: Plasma, urine and faecal samples from COVID-19 patients and control individuals were analysed to study peptidomic toxins' profiles. Protein precipitation preparation procedure was used for plasma, to remove high molecular weight proteins and efficiently solubilize the peptide fraction; in the case of faeces and urine, direct peptide solubilization was employed.   Results: Toxin-like peptides, almost identical to toxic components of venoms from animals, like conotoxins, phospholipases, phosphodiesterases, zinc metal proteinases, and bradykinins, were identified in samples from COVID-19 patients, but not in control samples.  Conclusions: The presence of toxin-like peptides could potentially be connected to SARS-CoV-2 infection. Their presence suggests a possible association between COVID-19 disease and the release in the body of (oligo-)peptides almost identical to toxic components of venoms from animals. Their involvement in a large set of heterogeneous extra-pulmonary COVID-19 clinical manifestations, like neurological ones, cannot be excluded. Although the presence of each individual symptom is not selective of the disease, their combination might be related to COVID-19 by the coexistence of the panel of the here detected toxin-like peptides. The presence of these peptides opens new scenarios on the aetiology of the COVID-19 clinical symptoms observed up to now, including neurological manifestations.


Asunto(s)
COVID-19 , Heces , Humanos , Pandemias , Péptidos , SARS-CoV-2
5.
F1000Res ; 10: 370, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34336189

RESUMEN

Background Scientific evidence for the involvement of human microbiota in the development of COVID-19 disease has been reported recently. SARS-CoV-2 RNA presence in human faecal samples and SARS-CoV-2 activity in faeces from COVID-19 patients have been observed. Methods Starting from these observations, an experimental design was developed to cultivate in vitro faecal microbiota from infected individuals, to monitor the presence of SARS-CoV-2, and to collect data on the relationship between faecal bacteria and the virus. Results Our results indicate that SARS-CoV-2 replicates in vitro in bacterial growth medium, that the viral replication follows bacterial growth and it is influenced by the administration of specific antibiotics. SARS-CoV-2-related peptides have been detected in 30-day bacterial cultures and characterised. Discussion Our observations are compatible with a 'bacteriophage-like' behaviour of SARS-CoV-2, which, to our knowledge has not been observed or described before. These results are unexpected and hint towards a novel hypothesis on the biology of SARS-CoV-2 and on the COVID-19 epidemiology. The discovery of possible new modes of action of SARS-CoV-2 has far-reaching implications for the prevention and the treatment of the disease.


Asunto(s)
COVID-19 , SARS-CoV-2 , Biología , Heces , Humanos , ARN Viral
6.
Viruses ; 13(7)2021 07 13.
Artículo en Inglés | MEDLINE | ID: mdl-34372565

RESUMEN

More than a year after the first identification of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as the causative agent of the 2019 coronavirus disease (COVID-19) in China, the emergence and spread of genomic variants of this virus through travel raise concerns regarding the introduction of lineages in previously unaffected regions, requiring adequate containment strategies. Concomitantly, such introductions fuel worries about a possible increase in transmissibility and disease severity, as well as a possible decrease in vaccine efficacy. Military personnel are frequently deployed on missions around the world. As part of a COVID-19 risk mitigation strategy, Belgian Armed Forces that engaged in missions and operations abroad were screened (7683 RT-qPCR tests), pre- and post-mission, for the presence of SARS-CoV-2, including the identification of viral lineages. Nine distinct viral genotypes were identified in soldiers returning from operations in Niger, the Democratic Republic of the Congo, Afghanistan, and Mali. The SARS-CoV-2 variants belonged to major clades 19B, 20A, and 20B (Nextstrain nomenclature), and included "variant of interest" B.1.525, "variant under monitoring" A.27, as well as lineages B.1.214, B.1, B.1.1.254, and A (pangolin nomenclature), some of which are internationally monitored due to the specific mutations they harbor. Through contact tracing and phylogenetic analysis, we show that isolation and testing policies implemented by the Belgian military command appear to have been successful in containing the influx and transmission of these distinct SARS-CoV-2 variants into military and civilian populations.


Asunto(s)
COVID-19/virología , Personal Militar , SARS-CoV-2/clasificación , SARS-CoV-2/genética , Afganistán/epidemiología , Bélgica , COVID-19/epidemiología , China/epidemiología , República Democrática del Congo/epidemiología , Genoma Viral , Genómica , Humanos , Malí/epidemiología , Epidemiología Molecular , Mutación , Niger/epidemiología , Filogenia , Viaje , Secuenciación Completa del Genoma
7.
F1000Res ; 10: 80, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-35847383

RESUMEN

Next Generation Sequencing technologies significantly impact the field of Antimicrobial Resistance (AMR) detection and monitoring, with immediate uses in diagnosis and risk assessment. For this application and in general, considerable challenges remain in demonstrating sufficient trust to act upon the meaningful information produced from raw data, partly because of the reliance on bioinformatics pipelines, which can produce different results and therefore lead to different interpretations. With the constant evolution of the field, it is difficult to identify, harmonise and recommend specific methods for large-scale implementations over time. In this article, we propose to address this challenge through establishing a transparent, performance-based, evaluation approach to provide flexibility in the bioinformatics tools of choice, while demonstrating proficiency in meeting common performance standards. The approach is two-fold: first, a community-driven effort to establish and maintain "live" (dynamic) benchmarking platforms to provide relevant performance metrics, based on different use-cases, that would evolve together with the AMR field; second, agreed and defined datasets to allow the pipelines' implementation, validation, and quality-control over time. Following previous discussions on the main challenges linked to this approach, we provide concrete recommendations and future steps, related to different aspects of the design of benchmarks, such as the selection and the characteristics of the datasets (quality, choice of pathogens and resistances, etc.), the evaluation criteria of the pipelines, and the way these resources should be deployed in the community.


Asunto(s)
Benchmarking , Secuenciación de Nucleótidos de Alto Rendimiento , Antibacterianos/farmacología , Biología Computacional/métodos , Farmacorresistencia Bacteriana/genética , Secuenciación de Nucleótidos de Alto Rendimiento/métodos
8.
Mol Oncol ; 15(10): 2507-2543, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34515408

RESUMEN

Key stakeholders from the cancer research continuum met in May 2021 at the European Cancer Research Summit in Porto to discuss priorities and specific action points required for the successful implementation of the European Cancer Mission and Europe's Beating Cancer Plan (EBCP). Speakers presented a unified view about the need to establish high-quality, networked infrastructures to decrease cancer incidence, increase the cure rate, improve patient's survival and quality of life, and deal with research and care inequalities across the European Union (EU). These infrastructures, featuring Comprehensive Cancer Centres (CCCs) as key components, will integrate care, prevention and research across the entire cancer continuum to support the development of personalized/precision cancer medicine in Europe. The three pillars of the recommended European infrastructures - namely translational research, clinical/prevention trials and outcomes research - were pondered at length. Speakers addressing the future needs of translational research focused on the prospects of multiomics assisted preclinical research, progress in Molecular and Digital Pathology, immunotherapy, liquid biopsy and science data. The clinical/prevention trial session presented the requirements for next-generation, multicentric trials entailing unified strategies for patient stratification, imaging, and biospecimen acquisition and storage. The third session highlighted the need for establishing outcomes research infrastructures to cover primary prevention, early detection, clinical effectiveness of innovations, health-related quality-of-life assessment, survivorship research and health economics. An important outcome of the Summit was the presentation of the Porto Declaration, which called for a collective and committed action throughout Europe to develop the cancer research infrastructures indispensable for fostering innovation and decreasing inequalities within and between member states. Moreover, the Summit guidelines will assist decision making in the context of a unique EU-wide cancer initiative that, if expertly implemented, will decrease the cancer death toll and improve the quality of life of those confronted with cancer, and this is carried out at an affordable cost.


Asunto(s)
Neoplasias , Calidad de Vida , Europa (Continente)/epidemiología , Humanos , Neoplasias/epidemiología , Neoplasias/prevención & control , Medicina de Precisión , Investigación Biomédica Traslacional
9.
BMC Biotechnol ; 10: 55, 2010 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-20687918

RESUMEN

BACKGROUND: The modular approach to analysis of genetically modified organisms (GMOs) relies on the independence of the modules combined (i.e. DNA extraction and GM quantification). The validity of this assumption has to be proved on the basis of specific performance criteria. RESULTS: An experiment was conducted using, as a reference, the validated quantitative real-time polymerase chain reaction (PCR) module for detection of glyphosate-tolerant Roundup Ready(R) GM soybean (RRS). Different DNA extraction modules (CTAB, Wizard and Dellaporta), were used to extract DNA from different food/feed matrices (feed, biscuit and certified reference material [CRM 1%]) containing the target of the real-time PCR module used for validation. Purity and structural integrity (absence of inhibition) were used as basic criteria that a DNA extraction module must satisfy in order to provide suitable template DNA for quantitative real-time (RT) PCR-based GMO analysis. When performance criteria were applied (removal of non-compliant DNA extracts), the independence of GMO quantification from the extraction method and matrix was statistically proved, except in the case of Wizard applied to biscuit. A fuzzy logic-based procedure also confirmed the relatively poor performance of the Wizard/biscuit combination. CONCLUSIONS: For RRS, this study recognises that modularity can be generally accepted, with the limitation of avoiding combining highly processed material (i.e. biscuit) with a magnetic-beads system (i.e. Wizard).


Asunto(s)
Análisis de los Alimentos/métodos , Glycine max/genética , Plantas Modificadas Genéticamente/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Alimentación Animal/análisis , ADN de Plantas/análisis , ADN de Plantas/aislamiento & purificación , Alimentos Modificados Genéticamente , Proyectos Piloto
10.
Transgenic Res ; 19(1): 57-65, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19533405

RESUMEN

This paper illustrates the advantages that a fuzzy-based aggregation method could bring into the validation of a multiplex method for GMO detection (DualChip GMO kit, Eppendorf). Guidelines for validation of chemical, bio-chemical, pharmaceutical and genetic methods have been developed and ad hoc validation statistics are available and routinely used, for in-house and inter-laboratory testing, and decision-making. Fuzzy logic allows summarising the information obtained by independent validation statistics into one synthetic indicator of overall method performance. The microarray technology, introduced for simultaneous identification of multiple GMOs, poses specific validation issues (patterns of performance for a variety of GMOs at different concentrations). A fuzzy-based indicator for overall evaluation is illustrated in this paper, and applied to validation data for different genetically modified elements. Remarks were drawn on the analytical results. The fuzzy-logic based rules were shown to be applicable to improve interpretation of results and facilitate overall evaluation of the multiplex method.


Asunto(s)
Lógica Difusa , Técnicas Genéticas/estadística & datos numéricos , Organismos Modificados Genéticamente/genética , Estudios de Validación como Asunto , Algoritmos , Animales , Recolección de Datos/métodos , Recolección de Datos/estadística & datos numéricos , Interpretación Estadística de Datos , Análisis por Micromatrices/métodos , Análisis por Micromatrices/estadística & datos numéricos
11.
Anal Bioanal Chem ; 396(6): 1991-2002, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19876618

RESUMEN

The steady rate of development and diffusion of genetically modified plants and their increasing diversification of characteristics, genes and genetic control elements poses a challenge in analysis of genetically modified organisms (GMOs). It is expected that in the near future the picture will be even more complex. Traditional approaches, mostly based on the sequential detection of one target at a time, or on a limited multiplexing, allowing only a few targets to be analysed at once, no longer meet the testing requirements. Along with new analytical technologies, new approaches for the detection of GMOs authorized for commercial purposes in various countries have been developed that rely on (1) a smart and accurate strategy for target selection, (2) the use of high-throughput systems or platforms for the detection of multiple targets and (3) algorithms that allow the conversion of analytical results into an indication of the presence of individual GMOs potentially present in an unknown sample. This paper reviews the latest progress made in GMO analysis, taking examples from the most recently developed strategies and tools, and addresses some of the critical aspects related to these approaches.


Asunto(s)
Técnicas Genéticas , Ensayos Analíticos de Alto Rendimiento/métodos , Plantas Modificadas Genéticamente/genética
12.
Viruses ; 12(9)2020 08 27.
Artículo en Inglés | MEDLINE | ID: mdl-32867108

RESUMEN

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) compromises the ability of military forces to fulfill missions. At the beginning of May 2020, 22 out of 70 Belgian soldiers deployed to a military education and training center in Maradi, Niger, developed mild COVID-19 compatible symptoms. Immediately upon their return to Belgium, and two weeks later, all seventy soldiers were tested for SARS-CoV-2 RNA (RT-qPCR) and antibodies (two immunoassays). Nine soldiers had at least one positive COVID-19 diagnostic test result. Five of them exhibited COVID-19 symptoms (mainly anosmia, ageusia, and fever), while four were asymptomatic. In four soldiers, SARS-CoV-2 viral load was detected and the genomes were sequenced. Conventional and genomic epidemiological data suggest that these genomes have an African most recent common ancestor and that the Belgian military service men were infected through contact with locals. The medical military command implemented testing of all Belgian soldiers for SARS-CoV-2 viral load and antibodies, two to three days before their departure on a mission abroad or on the high seas, and for specific missions immediately upon their return in Belgium. Some military operational settings (e.g., training camps in austere environments and ships) were also equipped with mobile infectious disease (COVID-19) testing capacity.


Asunto(s)
Betacoronavirus/aislamiento & purificación , Infecciones por Coronavirus/epidemiología , Personal Militar/estadística & datos numéricos , Neumonía Viral/epidemiología , Adulto , Bélgica/epidemiología , COVID-19 , Prueba de COVID-19 , Técnicas de Laboratorio Clínico , Infecciones por Coronavirus/diagnóstico , Brotes de Enfermedades , Humanos , Masculino , Epidemiología Molecular , Niger/epidemiología , Pandemias , Neumonía Viral/diagnóstico , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , SARS-CoV-2 , Pruebas Serológicas , Carga Viral , Adulto Joven
13.
F1000Res ; 9: 1296, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33564397

RESUMEN

The JRC COVID-19 In Vitro Diagnostic Devices and Test Methods Database, aimed to collect in a single place all publicly available information on performance of CE-marked in vitro diagnostic medical devices (IVDs) as well as in house laboratory-developed devices and related test methods for COVID-19, is here presented. The database, manually curated and regularly updated, has been developed as a follow-up to the Communication from the European Commission "Guidelines on in vitro diagnostic tests and their performance" of 15 April 2020 and is freely accessible at https://covid-19-diagnostics.jrc.ec.europa.eu/.


Asunto(s)
COVID-19/diagnóstico , Bases de Datos Factuales , Juego de Reactivos para Diagnóstico , Unión Europea , Humanos
14.
Artículo en Inglés | MEDLINE | ID: mdl-30985273

RESUMEN

Whereas the dramatic environmental impact of plastic waste rightfully receives considerable attention by scientists, policy makers and public in general, the human health impact of micro- and nanoplastics contamination of our food and beverages remains largely unknown. Indeed, most studies aim at understanding the environmental impact rather than the human health impact of a possible exposure to micro- and nanoplastics. In addition, these papers generally lack a methodological, standardised approach. Furthermore, some studies focus on the damage to and contamination level of animal species collected from the wild environment, and others investigate the rate and biology of microplastic uptake of animals fed with microplastics in laboratory. This review aims at understanding human exposure. Since there is, with few exceptions, no evidence available on the presence of micro- and nanoplastics in a normal diet, this study takes an indirect approach and analyses peer-reviewed publications since 2010 that document the presence of micro- and nanoplastics in those animals (more than 200 species) and food products that are part of the human food chain and that may thus contribute directly or indirectly to the uptake of micro- and nanoplastics via the human diet. It also addresses the question of the definitions, the methodologies and the quality criteria applied to obtain the reported results. This review suggests that, beyond a few estimations and comparisons, precise data to assess the exact exposure of humans to micro- and nanoplastics through their diet cannot be produced until standardised methods and definitions are available.


Asunto(s)
Contaminación de Alimentos/análisis , Abastecimiento de Alimentos , Plásticos/análisis , Animales , Humanos
15.
F1000Res ; 72018.
Artículo en Inglés | MEDLINE | ID: mdl-30026930

RESUMEN

Next-Generation Sequencing (NGS) technologies are expected to play a crucial role in the surveillance of infectious diseases, with their unprecedented capabilities for the characterisation of genetic information underlying the virulence and antimicrobial resistance (AMR) properties of microorganisms.  In the implementation of any novel technology for regulatory purposes, important considerations such as harmonisation, validation and quality assurance need to be addressed.  NGS technologies pose unique challenges in these regards, in part due to their reliance on bioinformatics for the processing and proper interpretation of the data produced.  Well-designed benchmark resources are thus needed to evaluate, validate and ensure continued quality control over the bioinformatics component of the process.  This concept was explored as part of a workshop on "Next-generation sequencing technologies and antimicrobial resistance" held October 4-5 2017.   Challenges involved in the development of such a benchmark resource, with a specific focus on identifying the molecular determinants of AMR, were identified. For each of the challenges, sets of unsolved questions that will need to be tackled for them to be properly addressed were compiled. These take into consideration the requirement for monitoring of AMR bacteria in humans, animals, food and the environment, which is aligned with the principles of a "One Health" approach.


Asunto(s)
Antibacterianos/farmacología , Biología Computacional/métodos , Farmacorresistencia Bacteriana/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Benchmarking
16.
J Agric Food Chem ; 55(4): 1071-6, 2007 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-17300145

RESUMEN

An innovative covalent microsphere immunoassay, based on the usage of fluorescent beads coupled to a specific antibody, was developed for the quantification of the endotoxin Cry1Ab present in MON810 and Bt11 genetically modified (GM) maize lines. In particular, a specific protocol was developed to assess the presence of Cry1Ab in a very broad range of GM maize concentrations, from 0.1 to 100% [weight of genetically modified organism (GMO)/weight]. Test linearity was achieved in the range of values from 0.1 to 3%, whereas fluorescence signal increased following a nonlinear model, reaching a plateau at 25%. The limits of detection and quantification were equal to 0.018 and 0.054%, respectively. The present study describes the first application of quantitative high-throughput immunoassays in GMO analysis.


Asunto(s)
Proteínas Bacterianas/análisis , Toxinas Bacterianas/análisis , Endotoxinas/análisis , Colorantes Fluorescentes , Proteínas Hemolisinas/análisis , Inmunoensayo/métodos , Microesferas , Plantas Modificadas Genéticamente/química , Zea mays/química , Toxinas de Bacillus thuringiensis , Proteínas Bacterianas/genética , Toxinas Bacterianas/genética , Endotoxinas/genética , Proteínas Hemolisinas/genética , Plantas Modificadas Genéticamente/genética , Semillas/química , Zea mays/genética
17.
J AOAC Int ; 90(5): 1432-8, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17955990

RESUMEN

A Windows-based software tool [Analytical Method Performance Evaluation (AMPE)] was developed to support the validation of analytical methods. The software implements standard statistical approaches commonly adopted in validation studies to estimate analytical method performance (limits of detection and quantitation, accuracy, specificity, working range, and linearity of responses) according to ISO 5725. In addition, AMPE proposes the application of innovative and unique approaches for the assessment of analytical method performance. Specifically, AMPE proposes the use of difference-based indexes to quantify the agreement between measurements and reference values, the use of pattern indexes to quantify methods bias with respect to specific external variables, and the application of fuzzy logic to aggregate into synthetic indicators the information collected independently via the different performance statistics traditionally estimated in validation studies. Aggregated measures are particularly useful for methods comparison, when more than one method is available for a specific analysis and it may be of interest to identify the best performing one taking into account, simultaneously, the information available from different performance statistics. Illustrative examples of the type of outputs expected from AMPE-based validation sessions are given. The extensive data handling capabilities and the wide range of statistics supplied in the software package makes AMPE suitable for specific needs that may arise in different validation studies. The installation package, complete with a fully documented help file, is distributed free of charge to interested users along with input files exemplary of the type of entry data required to run validation data analyses.


Asunto(s)
Técnicas de Química Analítica/métodos , Calibración , Técnicas de Química Analítica/normas , Técnicas de Laboratorio Clínico , Estudios de Evaluación como Asunto , Internet , Modelos Estadísticos , Valores de Referencia , Análisis de Regresión , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Programas Informáticos
18.
J Agric Food Chem ; 54(8): 2799-809, 2006 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-16608192

RESUMEN

Analytical methods for the qualitative and quantitative detection of genetically modified (GM) products may serve multiple purposes. Legal requirements differ among jurisdictions, ranging from no requirements to mandatory use of event-specific quantitation and implementation of production chain traceability. Although efforts have been taken to harmonize the analytical methodology at national, regional, and international levels, no normative international standards have yet been established. Lack of coherence between analytical methodologies and their applicabilities, on the one hand, and legislation, on the other hand, is a major problem. Here, key points where coherence is lacking are discussed. These include the definition of units of measurements, expression of GM material quantities, terminology, and inconsistent legal status of products derived from related but slightly different transformation routes. Finally, recommendations to improve the coherence are brought forward, including guidance to stakeholders for prediction of product-specific GM material quantities from gene ratios in the originating seed.


Asunto(s)
Ingeniería Genética/legislación & jurisprudencia , Plantas Modificadas Genéticamente , Secuencia de Bases , ADN de Plantas/química , ADN de Plantas/genética , Alimentos Modificados Genéticamente , Marcadores Genéticos , Plantas Modificadas Genéticamente/química , Plantas Modificadas Genéticamente/genética , Semillas/genética , Zea mays/genética
20.
J Agric Food Chem ; 53(8): 3041-52, 2005 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-15826057

RESUMEN

Since the 18th of April 2004, two new regulations, EC/1829/2003 on genetically modified food and feed products and EC/1830/2003 on traceability and labeling of GMOs, are in force in the EU. This new, comprehensive regulatory framework emphasizes the need of an adequate tracing system. Unique identifiers, such as the transgene genome junction region or a specific rearrangement within the transgene DNA, should form the basis of such a tracing system. In this study, we describe the development of event-specific tracing systems for transgenic maize lines Bt11, Bt176, and GA21 and for canola event GT73. Molecular characterization of the transgene loci enabled us to clone an event-specific sequence into a plasmid vector, to be used as a marker, and to develop line-specific primers. Primer specificity was tested through qualitative PCRs and dissociation curve analysis in SYBR Green I real-time PCRs. The primers were then combined with event-specific TaqMan probes in quantitative real-time PCRs. Calibration curves were set up both with genomic DNA samples and the newly synthesized plasmid DNA markers. It is shown that cloned plasmid GMO target sequences are perfectly suitable as unique identifiers and quantitative calibrators. Together with an event-specific primer pair and a highly specific TaqMan probe, the plasmid markers form crucial components of a unique and straighforward tracing system for Bt11, Bt176, and GA21 maize and GT73 canola events.


Asunto(s)
Brassica rapa/genética , Plantas Modificadas Genéticamente/genética , Plásmidos/genética , Reacción en Cadena de la Polimerasa/métodos , Zea mays/genética , Secuencia de Bases , ADN de Plantas/química , Marcadores Genéticos , Datos de Secuencia Molecular , Sensibilidad y Especificidad , Análisis de Secuencia de ADN
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