43 research outputs found
Bacteriophages in bathing wĂ ters: A feasibility study on the development of a method based on bacteriophages for the determination of microbiological quality of bathing waters
Projecte: Project report. BCR Information. EU project KINA19506ENC_001. EUROPEAN COMMISSION. Community Research. DG XII/C - Competitive and Sustainable Growth Programme. Published by EU Directorate General ΧΠ- Science, Research and Development ISBN 92-828-9145-3Informe final projecte europeu aigües de bany i bacteriòfagsMethods for the detection and enumeration of somatic coliphages, F-specific RNA bacteriophages and bacteriophages infecting Bacteroides fragilis had been standardised and validated. Conditions for the preparation, transport and distribution of bacteriophage reference materials and preservation of samples had been defined. A method based on flocculation with Mg(OH2) with concentration efficiencies from about 40% was settled to concentrate phages from bathing waters. All methods were successfully implemented in routine laboratories all around the EU. Data on the occurrence of bacteriophages as compared to E. coli and Enterococci are available from diverse situations encountered in the EU. Results allow to conclude that the potential of phages for the determination of the microbiological quality of bathing waters merits to be considered since their determination is feasible and their behaviour in natural water differs from the behaviour of bacterial indicators and consequently they add valuable information
Breakpoint mapping of 13 large parkin deletions/duplications reveals an exon 4 deletion and an exon 7 duplication as founder mutations
Early-onset Parkinson’s disease (EOPD) has been associated with recessive mutations in parkin (PARK2). About half of the mutations found in parkin are genomic rearrangements, i.e., large deletions or duplications. Although many different rearrangements have been found in parkin before, the exact breakpoints involving these rearrangements are rarely mapped. In the present study, the exact breakpoints of 13 different parkin deletions/duplications, detected in 13 patients out of a total screened sample of 116 EOPD patients using Multiple Ligation Probe Amplification (MLPA) analysis, were mapped using real time quantitative polymerase chain reaction (PCR), long-range PCR and sequence analysis. Deletion/duplication-specific PCR tests were developed as a rapid and low cost tool to confirm MLPA results and to test family members or patients with similar parkin deletions/duplications. Besides several different deletions, an exon 3 deletion, an exon 4 deletion and an exon 7 duplication were found in multiple families. Haplotype analysis in four families showed that a common haplotype of 1.2 Mb could be distinguished for the exon 7 duplication and a common haplotype of 6.3 Mb for the deletion of exon 4. These findings suggest common founder effects for distinct large rearrangements in parkin
Using social and behavioural science to support COVID-19 pandemic response
The COVID-19 pandemic represents a massive global health crisis. Because the crisis requires large-scale behaviour change and places significant psychological burdens on individuals, insights from the social and behavioural sciences can be used to help align human behavior with the recommendations of epidemiologists and public health experts. Here we discuss evidence from a selection of research topics relevant to pandemics, including work on navigating threats, social and cultural influences on behaviour, science communication, moral decision-making, leadership, and stress and coping. In each section, we note the nature and quality of prior research, including uncertainty and unsettled issues. We identify several insights for effective response to the COVID-19 pandemic, and also highlight important gaps researchers should move quickly to fill in the coming weeks and months
EURL-Salmonella ringonderzoek Voedsel-Diervoeder 2023. Detectie van Salmonella in lijnzaad
In 2023, 50 National Reference Laboratories for Salmonella (NRLsSalmonella) obtained a good score in a Proficiency Test for Salmonella bacteria. One laboratory initially scored a moderate performance due to an administrative error. Eventually, this laboratory also obtained a good score by providing the correct result with raw data. The NRLs-Salmonella of the European Union (EU) Member States are obliged to participate in annual quality monitoring exercises, known as Proficiency Tests. One of these Proficiency Tests checks whether NRLs can detect Salmonella bacteria in food and feed. The matrix chosen for this year’s Proficiency Test was flaxseed. Each EU Member State has to appoint a NRL that is responsible for performing these analysis in its laboratory. The 51 participants in this Proficiency Test came from 27 EU Member States and from seven other European countries. The laboratories used an obligatory, internationally accepted method to detect the presence of Salmonella in flaxseed. Each laboratory received a package containing samples that had either been artificially contaminated with two different concentrations of Salmonella Typhimurium or did not contain this bacterium. This Proficiency Test is organised by the European Union Reference Laboratory for Salmonella (EURL-Salmonella). This is part of the Dutch National Institute for Public Health and the Environment (RIVM). An important task of the EURL-Salmonella is to monitor the performance of the NRLs for Salmonella in Europe.Vijftig Nationale Referentie Laboratoria voor Salmonella (NRL’sSalmonella) hebben in 2023 een goede score gehaald in het ringonderzoek voor de Salmonella-bacterie. Eén laboratorium haalde eerst een matige score door een administratieve fout. Dit laboratorium haalde uiteindelijk ook een goede score door met ruwe data het juiste resultaat te geven. De NRL’s-Salmonella uit de lidstaten van de Europese Unie zijn verplicht om elk jaar hun kwaliteit te laten toetsen met zogeheten ringonderzoeken. Een van de ringonderzoeken controleert of de NRL’s de Salmonella-bacterie in voedsel en diervoeder kunnen aantonen; dit keer in lijnzaad. Elk lidstaat van de EU(European Union ) wijst hiervoor het NRL aan dat verantwoordelijk is voor deze testen in hun laboratorium. De 51 deelnemers in dit ringonderzoek kwamen uit 27 lidstaten van de Europese Unie en uit zeven andere Europese landen. De laboratoria gebruikten een verplichte, internationaal erkende analysemethode om Salmonella in monsters lijnzaad aan te tonen. Elk laboratorium kreeg een pakket toegestuurd met monsters die kunstmatig besmet waren met twee verschillende concentraties Salmonella Typhimurium of zonder deze bacterie. Het ringonderzoek is georganiseerd door het Europese Unie Referentie Laboratorium voor Salmonella (EURL-Salmonella). Dit is gevestigd bij het RIVM. Een belangrijke taak van het EURL-Salmonella is toezien op de kwaliteit van de NRL’s-Salmonella in Europa
Het EURL-Salmonella ringonderzoek productiedieren (2021). Detectie van Salmonella in kippenmest op overschoentjes
In the annual EURL-Salmonella Proficiency Test performed in 2021, the National Reference Laboratories (NRLs) of the European (EU) Member States were able to detect Salmonella in chicken faeces adhering to boot socks. All laboratories were able to detect Salmonella in high and low concentrations in the contaminated boot sock samples. All but one laboratory achieved good results. This one laboratory had accidentally swapped control samples, resulting in a moderate performance score. This was the outcome of the Proficiency Test for the detection of Salmonella in samples from the primary production stage, organised by the coordinating European Union Reference Laboratory for Salmonella (EURL-Salmonella) in September 2021. Since 1992, all NRLs in EU Member States are obliged to participate in the annual quality control proficiency tests for Salmonella. Each Member State has to appoint an NRL with responsibility for analysing Salmonella in samples taken from the animal primary production stage. In total, 35 NRLs participated in this study: 27 NRLs originating from all 27 EU Member States, seven NRLs based in other countries in Europe and one NRL based in a non-European country. The EURL-Salmonella is based at the Dutch National Institute for Public Health and the Environment (RIVM). An important task of the EURLSalmonella is to monitor and improve the performance of the NRLs in Europe.De Nationale Referentie Laboratoria (NRL’s) van de Europese lidstaten waren in 2021 in staat om Salmonella aan te tonen in kippenmest op overschoentjes. Alle deelnemers konden hoge en lage concentraties van Salmonella aantonen. Op één na hebben alle laboratoria een goede score behaald. Dat ene laboratorium had de controlemonsters verwisseld en haalde daarom een matige score. Dit blijkt uit het jaarlijkse ringonderzoek dat het Europese Referentielaboratorium (EURL) voor Salmonella in september 2021 organiseerde. Sinds 1992 zijn de NRL’s van de Europese lidstaten verplicht om elk jaar mee te doen aan kwaliteitstoetsen. Dit zijn de zogeheten ringonderzoeken voor Salmonella. Elke lidstaat wijst hiervoor een laboratorium aan, het Nationale Referentie Laboratorium. Deze laboratoria zijn er namens dat land voor verantwoordelijk Salmonella aan te tonen in de leefomgeving van dieren die voor de voedselproductie worden gehouden. In totaal hebben 35 NRL’s aan dit ringonderzoek deelgenomen: 27 NRL’s afkomstig uit alle 27 EU-lidstaten, zeven NRL’s uit andere Europese landen en één NRL uit een niet-Europees land. Het EURL-Salmonella is gevestigd bij het Nederlandse Rijksinstituut voor Volksgezondheid en Milieu (RIVM). Een belangrijke taak van het EURLSalmonella is toezien op de kwaliteit van de nationale referentielaboratoria voor deze bacterie in Europa
A Simple and Widely Applicable Method for Preparing Homogeneous and Stable Quality Control Samples in Water Microbiology
Both SSU rDNA and RNA polymerase II data recognise that root-knot nematodes arose from migratory Pratylenchidae, but probably not from one of the economically high-impact lesion nematodes
In 2000 Siddiqi formulated a hypothesis stating that root-knot nematodes (Meloidogyne spp.) constitute a branch arising from yet another important group of plant parasites, the migratory Pratylenchidae. This hypothesis was solely based on morphological characteristics. Ribosomal DNA (rDNA) sequence analysis supports this hypothesis in its broad sense, but the more precise question about the identity of a migratory Pratylenchidae representative being closest to the most basal Meloidogyne species could not be addressed due to a lack of backbone resolution (Holterman et al., 2009). Here we present an extended small subunit rDNA sequence analysis and a data set of partial RNA polymerase II sequences from Pratylenchidae and basal Meloidogynidae. Our data point at members of the genus Pratylenchus as being closest to the common ancestor of the root-knot nematodes, but it was not possible unequivocally to identify a candidate lesion nematode species. Pratylenchus is a species-rich genus (ca 70 valid species), and we suggest that the species closest to the most basal root-knot nematode should be sought outside of the group of relatively well-characterised, agronomically relevant, species
Multidisciplinary investigation of a multicountry outbreak of Salmonella Stanley infections associated with turkey meat in the European Union, August 2011 to January 2013
Between August 2011 and January 2013, an outbreak of Salmonella enterica serovar Stanley (S. Stanley) infections affected 10 European Union (EU) countries, with a total of 710 cases recorded. Following an urgent inquiry in the Epidemic Intelligence Information System for food- and waterborne diseases (EPIS-FWD) on 29 June 2012, an international investigation was initiated including EU and national agencies for public health, veterinary health and food safety. Two of three local outbreak investigations undertaken by affected countries in 2012 identified turkey meat as a vehicle of infection. Furthermore, routine EU monitoring of animal sources showed that over 95% (n=298) of the 311 S. Stanley isolates reported from animal sampling in 2011 originated from the turkey food production chain. In 2004–10, none had this origin. Pulsed-field gel electrophoresis (PFGE) profile analysis of outbreak isolates and historical S. Stanley human isolates revealed that the outbreak isolates had a novel PFGE profile that emerged in Europe in 2011. An indistinguishable PFGE profile was identified in 346 of 464 human, food, feed, environmental and animal isolates from 16 EU countries: 102 of 112 non-human isolates tested were from the turkey production chain. On the basis of epidemiological and microbiological evidence, turkey meat was considered the primary source of human infection, following contamination early in the animal production chain
Diastereoselective one-pot synthesis of tetrafunctionalized 2-imidazolines
A convenient trans-selective one-pot synthesis of tetrafunctionalized 2-imidazolines is described. Our approach to these valuable heterocyclic scaffolds involves a formal 1,3-dipolar cycloaddition between nitrile ylides or nitrilium triflates and imines. A detailed experimental study in combination with a high-level computational exploration of reaction routes reveals a plausible reaction pathway that accounts for the observed diastereoselectivity. © 2014 American Chemical Society
Investigation into de source of the legionellose epidemic after the Westfriese Gardenshow at Bovenkarspel
In maart 1999 kwam uit de resultaten van een orienterend patient-controle onderzoek naar voren dat de bron van een omvangrijke Legionella epidemie zich op of rond de Westfriese Flora (WF) te Bovenkarspel (Noord-Holland) moest bevinden. De WF is een jaarlijkse tentoonstelling van bloemen en agrarische en consumentenproducten, die in 1999 werd gehouden van 19 tot en met 28 februari. Na inspectie van het terrein en inventarisatie van de exposanten werd een lijst opgesteld van potentiele bronnen. Het waterleidingsysteem en alle watergebruikende installaties die nog voorhanden waren, werden bemonsterd. Aan de hand van interviews met exposanten, werd een risico-inschatting voor elke potentiele bron gemaakt. In totaal waren zestien producten potentieel risicovol: twee whirlpools, twee bubbelmatten (geperforeerde rubber matten, bedoeld om op de bodem van een met water gevuld bad te leggen, waardoorheen met hoge snelheid lucht kan worden geblazen), elf fonteinen en een vernevelaar. Uit drie apparaten, twee whirlpools en een vernevelaar, werd Legionella pneumophila geisoleerd. Gebruikmakend van serotypering en moleculair-biologische technieken (PFGE, ERIC/REP en AFLP), werden drie verschillende genotypen onderscheiden: B-1, B-2 en B3 (B van Bovenkarspel). Om deze isolaten met patienten-isolaten te kunnen vergelijken werkten alle microbiologische laboratoria van Nederland mee met het verzamelen van patienten-isolaten gerelateerd aan de epidemie. Van in totaal 29 verzamelde isolaten waren 28 genetisch identiek aan B-1, het andere was genetisch identiek aan B-2. Gebruikmakend van risico-inschatting gebaseerd op gemeld gebruik en gebruikmakend van een microbiologische inschatting van de mate van besmetting van de drie kweek-positieve producten, droeg de whirlpool in hal 3 van het WF-terrein zeer waarschijnlijk het meeste bij aan verspreiding van L. pneumophila. Het is niet uit te sluiten dat de whirlpool in hal 4 een bijdrage heeft geleverd aan de verspreiding, terwijl een bijdrage van de vernevelaar onwaarschijnlijk is. Ook een bijdrage aan de verspreiding door de fonteinen en de bubbelmatten is onwaarschijnlijk. Hoewel Legionella spp niet werden geisoleerd uit het waterleidingsysteem, is het waarschijnlijk dat de Legionella bacterien de drie producten binnenkwamen vanuit dit systeem. Deze resultaten worden bevestigd door de uitkomsten van een patient-controle en een cohort onderzoek, uitgevoerd om de exacte locatie van blootstelling aan Legionella spp op het WF-terrein vast te stellen, die aangeven dat de whirlpool in hal 3 de meest waarschijnlijke bron van infectie is.In March 1999 results from an exploratory case-control study indicated that the most probable origin of a large epidemic of legionnaire's disease had to be directly located at or in the surroundings of the Westfriese Flora (WF) in Bovenkarspel (Province of Noord-Holland, Netherlands). The WF is a yearly exhibition of flowers, and agricultural and consumer products, which was held in 1999 from 19 to 28 February. After inspecting the premises and making an inventory of all exhibits, a list of potential sources was drawn up. The water supply system and all the still available equipment using water were sampled. A risk assessment was done for each potential source by interviewing exhibitors. In total, sixteen products were found potentially hazardous: two whirlpools, two bubblemats (perforated rubber mats meant for the bottom of a water-filled bathtub through which air can be blown at high speed), eleven fountains and a sprinkler installation. Legionella pneumophila was isolated from two whirlpools and a sprinkler installation. With the use of molecular-biological techniques (PFGE, ERIC/REP-PCR and AFLP), three different genotypes were identified. These were B-1, B-2 and B-3 (B for Bovenkarspel). To enable comparison of these isolates with patient isolates, all microbiology laboratories in the Netherlands collaborated in collecting patient isolates related to the epidemic. In total 29 isolates were collected, 28 of which were genetically identical to B-1; the other one was genetically identical to B-2. Through the risk assessment based on the reported use and estimating the degree of contamination from the microbiological investigation of the three culture-positive products, the most probable source contributing the most to the spread of L. pneumophila was found to be the whirlpool located in hall 3 of the WF premises. It is not possible to rule out the contribution made to spreading by the whirlpool in hall 4, whereas the sprinkler's contribution to spreading is not probable. The contribution to spreading by the fountains and bubblemats is also unlikely. Although Legionella spp was not isolated from the water supply system, the organism was likely introduced into the three products from this system. These results were confirmed by the outcome of a case-control study and a cohort study, both designed to pinpoint the exact location of exposure to Legionella spp on the WF premises. They showed the whirlpool in hall 3 to be the most probable source of infection (reported separately).VW