Improved detection of Escherichia coli and coliform bacteria by multiplex PCR

Antecedentes: La presencia de bacterias coliformes es evaluado periódicamente para establecer la inocuidad microbiológica de los suministros de agua y materias o alimentos procesados. Los coliformes son un grupo de enterobacterias fermentadoras de lactosa, que probablemente adquirió la lacZ por transferencia horizontal de genes y, por lo tanto, constituyen un grupo polifiletico. Entre este grupo de bacterias Escherichia coli es el patógeno más frecuentemente asociadas con brotes de enfermedades de origen alimentario, y con frecuencia se identifica por Beta-glucuronidasa actividad enzimática o por la detección de uidA redundante por PCR. Debido a que una fracción importante de genes de la bacteria Escherichia coli esenciales se mantienen a lo largo de reino bacteriano, la alternativa de oligonucleótidos cebadores específicos para la detección de E. coli no son fácilmente identificables. Resultados: En este manuscrito, se utilizaron dos estrategias para diseñar cebadores oligonucleótidos con diferentes niveles de especificidad para la detección simultánea de coliformes totales y E. coli por PCR multiplex. Una secuencia consenso de lacZ y el gen huérfano yaiO fueron elegidos como objetivos para la amplificación, la obtención de 234 pb y 115 pb, respectivamente, productos de PCR. Conclusiones: El ensayo diseñado en esta labor de detección superior demostrada capacidad cuando se prueban con la colección de laboratorio y productos lácteos aislado cepas fermentadoras de lactosa. Mientras lacZ amplicones se encontraron en una amplia gama de bacterias coliformes, amplificación yaiO fue altamente específicas para E. coli. Además, la detección yaiO es no redundante con métodos enzimáticos.Background: The presence of coliform bacteria is routinely assessed to establish the microbiological safety of water supplies and raw or processed foods. Coliforms are a group of lactose-fermenting Enterobacteriaceae, which most likely acquired the lacZ gene by horizontal transfer and therefore constitute a polyphyletic group. Among this group of bacteria is Escherichia coli, the pathogen that is most frequently associated with foodborne disease outbreaks and is often identified by β-glucuronidase enzymatic activity or by the redundant detection of uidA by PCR. Because a significant fraction of essential E. coli genes are preserved throughout the bacterial kingdom, alternative oligonucleotide primers for specific E. coli detection are not easily identified. Results: In this manuscript, two strategies were used to design oligonucleotide primers with differing levels of specificity for the simultaneous detection of total coliforms and E. coli by multiplex PCR. A consensus sequence of lacZ and the orphan gene yaiO were chosen as targets for amplification, yielding 234 bp and 115 bp PCR products, respectively. Conclusions: The assay designed in this work demonstrated superior detection ability when tested with lab collection and dairy isolated lactose-fermenting strains. While lacZ amplicons were found in a wide range of coliforms, yaiO amplification was highly specific for E. coli. Additionally, yaiO detection is non-redundant with enzymatic methods.Trabajo patrocinado por: Ministerio de Ciencia e Innovación. Ayuda PCJ1007 Junta de Extremadura. Ayuda GR10058 Fondos FEDER FSEpeerReviewe

ECOPHAGE: Combating Antimicrobial Resistance Using Bacteriophages for Eco-Sustainable Agriculture and Food Systems

The focus of this meeting was to discuss the suitability of using bacteriophages as alternative antimicrobials in the agrifood sector. Following a One Health approach, the workshop explored the possibilities of implementing phage application strategies in the agriculture, animal husbandry, aquaculture, and food production sectors. Therefore, the meeting had gathered phage researchers, representatives of the agrifood industry, and policymakers to debate the advantages and potential shortcomings of using bacteriophages as alternatives to traditional antimicrobials and chemical pesticides. Industry delegates showed the latest objectives and demands from consumers. Representatives of regulatory agencies (European Medicines Agency (EMA) and Spanish Agency of Medicines and Health Products (AEMPS)) presented an update of new regulatory aspects that will impact and support the approval and implementation of phage application strategies across the different sectors

Microbiological and lipolytic changes in high-pressure-treated raw milk cheeses during refrigerated storage

International audienceAbstractHigh-pressure processing (HPP) has been used to control microorganisms and enzymes and avoid over-ripening in cheese. Excessive lipolysis is associated with over-ripening in cheese. However, little information about the effect of high pressure on microorganisms and lipolysis in mature cheese is available. For this reason, microbiological and lipolytic changes during refrigerated storage of pressurised Torta del Casar cheese (a raw ewe’s milk cheese) were studied. Mature cheeses (60 days of ripening) were high-pressure treated (200 or 600 MPa for 5 or 20 min) and stored at 6 °C. Cheese samples were analysed at day 60, just after high-pressure treatment, and during the refrigerated storage (at days 120, 180 and 240). Enterobacteriaceae counts were significantly reduced after high-pressure treatment, thus increasing the food safety of this cheese. In particular, Enterobacteriaceae showed a significant (p < 0.01) decrease of 2.18 and 2.46 log units in cheeses treated at 200 MPa for 20 min at days 120 and 180, respectively; however, treatment at 600 MPa for 20 min only caused reductions of 2.09 and 1.79 log units at days 120 and 180. Free fatty acids content was not significantly influenced by high-pressure treatment, although it increased with time of storage

Siento y disiento

El proyecto pretende recuperar la escuela como lugar de encuentro de los niños con su entorno; la utilización de las sensaciones y sentidos como herramientas de trabajo; el desarrollo del espíritu crítico entre los alumnos ante las agresiones del medio ambiente y la percepción del arte como bien para la naturaleza. En este proyecto destaca la participación casi al cien por cien de alumnos, profesores y padres. Los objetivos son conocer distintos aspectos de la naturaleza como los cambios estacionales, relaciones entre los seres vivos, formas de vida, o la capacidad de adaptación de los seres vivos; desarrollar la sensibilidad y el sentido estético hacia las diversas formas de expresión y representación. La metodología profundiza en el aprendizaje por descubrimiento a partir de la curiosidad, la observación directa y la experimentación. Se fomenta la comunicación entre todos los niveles, ciclos y estamentos educativos. Las actividades se dividen por trimestres y ciclos y en todos ellos realizan la decoración del pasillo en función de la estación del año en la que se encuentren. Otras actividades son el estudio de la alimentación de temporada, participación en el periódico de la escuela, visitas a museos, teatros y realización de fiestas y talleres. La evaluación valora los recursos, el tiempo de ejecución del programa, las fuentes utilizadas y el proceso de aprendizaje.Madrid (Comunidad Autónoma). Consejería de EducaciónMadridMadrid (Comunidad Autónoma). Subdirección General de Formación del Profesorado. CRIF Las Acacias; General Ricardos 179 - 28025 Madrid; Tel. + 34915250893ES

ECOPHAGE: Combating Antimicrobial Resistance Using Bacteriophages for Eco-Sustainable Agriculture and Food Systems

The focus of this meeting was to discuss the suitability of using bacteriophages as alternative antimicrobials in the agrifood sector. Following a One Health approach, the workshop explored the possibilities of implementing phage application strategies in the agriculture, animal husbandry, aquaculture, and food production sectors. Therefore, the meeting had gathered phage researchers, representatives of the agrifood industry, and policymakers to debate the advantages and potential shortcomings of using bacteriophages as alternatives to traditional antimicrobials and chemical pesticides. Industry delegates showed the latest objectives and demands from consumers. Representatives of regulatory agencies (European Medicines Agency (EMA) and Spanish Agency of Medicines and Health Products (AEMPS)) presented an update of new regulatory aspects that will impact and support the approval and implementation of phage application strategies across the different sectors