The Citizen, the Culture and European Union

From the beginning of its work (1988), the European Centre of Culture tried to attract the attention of the European institutions on the urgent need to bring in the greatest number of citizens a sense of belonging to a new space and a common destiny based on a common culture

Molecular characterization of Salmonella Enteritidis : comparison of an optimized multi-locus variable-number of tandem repeat analysis (MLVA) and pulsed-field gel electrophoresis

Salmonella Enteritidis (SE) is a genetically homogenous serovar, which makes optimal subtype discrimination crucial for epidemiological research. This study describes the development and evaluation of an optimized multiple-locus variable number tandem-repeat assay (MLVA) for characterization of SE. The typeability and discriminatory power of this MLVA was determined on a selected collection of 60 SE isolates and compared with pulsed-field gel electrophoresis (PFGE) using restriction enzymes XbaI, NotI, or SfiI. In addition, the estimated Wallace coefficient (W) was calculated to assess the congruence of the typing methods. Selection of epidemiologically unrelated isolates and more related isolates (originating from layer farms) was also based on the given phage type (PT). When targeting six loci, MLVA generated 16 profiles, while PFGE produced 10, 9, and 16 pulsotypes using XbaI, NotI, and SfiI, respectively, for the entire strain collection. For the epidemiologically unrelated isolates, MLVA had the highest discriminatory power and showed good discrimination between isolates from different layer farms and among isolates from the same layer farm. MLVA performed together with PT showed higher discriminatory power compared to PFGE using one restriction enzyme together with PT. Results showed that combining PT with the optimized MLVA presented here provides a rapid typing tool with good discriminatory power for characterizing SE isolates of various origins and isolates originating from the same layer farm

Correlation between bacteriology of lymph nodes and serology for Salmonella diagnosis in slaughter pigs

Salmonella control programs in pigs are usually based on serological tests. The major objective of this cross-sectional study was to investigate the correlation between the serological results and the bacteriological results of Salmonella diagnosis in pigs at the herd level and at the animal level. From 60 farrow-to-finish herds, serum samples and mesenterial lymph nodes from 30 fattening pigs were taken in the slaughterhouse

One Health EJP, european joint programming and funding of research on foodborne zoonoses

L’EJP One health est un projet européen de recherche destiné à éclairer la décision publique dans le domaine de la sécurité sanitaire des aliments (One Health EJP). Il a pour objectif de contribuer à renforcer les liens existants entre santé animale, santé humaine et l’environnement selon la démarche “Une seule santé” (Jestin & Davoust, 2015; Parodi, 2018). Co-financé par la Commission Européenne et les états membres de l’Union Européenne, ce projet regroupe 39 partenaires de 19 états membres. Ces centres publics de recherche, soit en santé publique soit en santé animale, mènent des travaux de recherche sur les zoonoses alimentaires, l’antibiorésistance et les maladies émergentes alimentaires tout en assurant les mandats de référence correspondants. La mise en œuvre de la démarche “Une seule santé” se fait par la mobilisation des deux communautés “Med” et “Vet”, dans une approche multidisciplinaire. Les priorités thématiques de recherche sont définies par les instituts de recherche après consultation des agences nationales et européennes d’évaluation des risques. Par cette approche l’EJP One Health est un projet de recherche destinée à générer des informations scientifiques essentielles à l’analyse et à l’évaluation des risques sanitaires, et à ce titre est en appui à la décision publique.The One Health concept recognizes that the human health is tightly connected to the health of animals and to the environment, i.e. that animal feed, human food, animal and human health, and environmental contamination are closely linked. These are the main focus of our European joint programme (EJP). One reference laboratory from the public health / medicine domain and one reference laboratory from the food / veterinary domain are associated within a network of 39 European laboratories and research centers, distributed in 19 participating member states, with the aim to reach significant advances in the fields of foodborne zoonoses, antimicrobial resistance and emerging threats within a global One Health approach. Most of these laboratories have reference responsibilities, representing a sustainable framework for an integrated research community. The One Health EJP aims at reinforcing collaboration between institutes by enhancing transdisciplinary cooperation and integration of activities. The One health EJP is a policy driven project, contributing to strengthen the decision of the policy makers

Protection of rabbits against enteropathogenic Escherichia coli (EPEC) using an intimin null mutant

BACKGROUND: Diarrhea and mortality resulting from infections with enteropathogenic Escherichia coli (EPEC) are of major economic importance in the rabbit meat industry. There is a growing need for an effective vaccine to cope with these problems and to reduce the use of antibiotics. EPEC are characterized by an attaching and effacing virulence mechanism. This is partly mediated by the intimate binding between an adhesin, called intimin, and a translocated receptor (Tir) of prokaryote origin. We constructed an intimin deletion mutant of the rabbit EPEC (REPEC) wild-type strain 97/241.6 (bio-/serogroup 3-/O15) and examined its protective capacity. RESULTS: After verifying its complete loss of virulence, we used the attenuated strain in vaccination-challenge experiments in which complete protection against a homologous, but virulent, strain was observed. The attenuated strain was able to persist in the intestinal lumen, where it elicited an immune response against EPEC-related virulence proteins, as was shown using an EspB-specific ELISA. Despite the priming of an immune response and the generation of specific antibodies, the intimin mutant was not able to fully protect rabbits against challenges with REPEC strains of other bio-/serogroups. CONCLUSION: These data indicate that protection against REPEC infections is at least partly bio-/serogroup dependent and a multivalent vaccine may be needed for protection against the full range of REPEC types. Such a combination vaccine may be developed using intimin null mutants, as the latter were clearly shown to be safe and effective against homologous infections

CHCHD2 harboring Parkinson's disease-linked T61I mutation precipitates inside mitochondria and induces precipitation of wild-type CHCHD2

The T61I mutation in CHCHD2, a protein residing in the mitochondrial intermembrane space, causes an autosomal dominant form of Parkinson’s disease (PD), but the underlying pathogenic mechanisms are not well understood. Here, we compared the subcellular localization and solubility of wild-type and T61I mutant CHCHD2 in human cells. We found that mitochondrial targeting of both wild-type and T61I CHCHD2 depended on the four cysteine residues in the C-terminal coiled-coil-helix-coiled-coil-helix (CHCH) domain but not on the N-terminal predicted mitochondrial targeting sequence. The T61I mutation did not interfere with mitochondrial targeting of the mutant protein, but induced its precipitation in the IMS. Moreover, T61I CHCHD2 induced increased mitochondrial production of reactive oxygen species (ROS) and apoptosis, which was prevented by treatment with anti-oxidants. Retention of T61I CHCHD2 in the cytosol through mutation of the cysteine residues in the CHCH domain prevented its precipitation as well as its apoptosis-inducing effect. Importantly, T61I CHCHD2 potently impaired the solubility of wild-type CHCHD2. In conclusion, our data show that the T61I mutation renders mutant CHCHD2 insoluble inside mitochondria, suggesting loss of function of the mutant protein. In addition, T61I CHCHD2 exerts a dominant-negative effect on the solubility of wild-type CHCHD2, explaining the dominant inheritance of this form of PD

CHARACTERIZATION OF F107 FIMBRIAE OF ESCHERICHIA-COLI 107/86, WHICH CAUSES EDEMA DISEASE IN PIGS, AND NUCLEOTIDE-SEQUENCE OF THE F107 MAJOR FIMBRIAL SUBUNIT GENE, FEDA

F107 fimbriae were isolated and purified from edema disease strain 107/86 of Escherichia coli. Plasmid pIH120 was constructed, which contains the gene cluster that codes for adhesive F107 fimbriae. The major fimbrial subunit gene, fedA, was sequenced. An open reading frame that codes for a protein with 170 amino acids, including a 21-amino-acid signal peptide, was found. The protein without the signal sequence has a calculated molecular mass of 15,099 Da. Construction of a nonsense mutation in the open reading frame of fedA abolished both fimbrial expression and the capacity to adhere to isolated porcine intestinal villi. In a screening of 28 reference edema disease strains and isolates from clinically ill piglets, fedA was detected in 24 cases (85.7%). In 20 (83.3%) of these 24 strains, fedA was found in association with Shiga-like toxin II variant genes, coding for the toxin that is characteristic for edema disease strains of E. coli. The fimbrial subunit gene was not detected in enterotoxigenic E. coli strains. Because of the capacity of E. coli HB101(pIH120) transformants to adhere to isolated porcine intestinal villi, the high prevalence of fedA in edema disease strains, and the high correlation with the Shiga-like toxin II variant toxin-encoding genes, we suggest that F107 fimbriae are an important virulence factor in edema disease strains of E. coli

Selection and transfer of an IncI1-tet(A) plasmid of Escherichia coli in an ex vivo model of the porcine caecum at doxycycline concentrations caused by cross-contaminated feed

Aims: The aim of this study was to investigate the effect of subtherapeutic intestinal doxycycline (DOX) concentrations (4 and 1mgl(-1)), caused by cross-contamination of feed, on the enrichment of a DOX-resistant commensal Escherichia coli and its resistance plasmid in an exvivo model of the porcine caecum. Methods and Results: A DOX-resistant, tet(A)-carrying, porcine commensal E.coli strain (EC 682) was cultivated for 6days in the porcine caecum model under different conditions (0, 1 and 4mgl(-1) DOX). EC 682, other coliforms and anaerobic bacteria were enumerated daily. A selection of isolated DOX-resistant coliforms (n=454) was characterized by rep-PCR clustering, PCR assays (Inc1 and tet(A)) and micro broth dilution susceptibility tests (Sensititre). Both 1 and 4mgl(-1) DOX-enriched medium had a significantly higher selective effect on EC 682 and other resistant coliforms than medium without DOX. Transconjugants of EC 682 were isolated more frequently in the presence of 1 and 4mgl(-1) DOX compared to medium without DOX. Conclusions: Subtherapeutic intestinal DOX concentrations have the potential to select for DOX-resistant E.coli, and promote the selection of transconjugants in a porcine caecum model. Significance and Impact of the Study: Cross-contamination of feed with antimicrobials such as DOX likely promotes the spread of antimicrobial resistance. Therefore, it is important to develop or fine-tune guidelines for the safe use of antimicrobials in animal feed and its storage

Bacteriological prevalence in finishing pig farms assigned as Salmonella risk farms by serological screening

The Belgian Federal Agency for the Safety of the Food Chain (FASFC) installed a National Salmonella surveillance and control program in pigs, the Salmonella Action Plan (SAP), which became compulsory by means of a Royal act in July 2007. Assignment as Salmonella risk farm is based on serological analysis of blood samples collected from the fattening pigs. The knowledge of prevailing serovars of Salmonella by bacteriological methods is essential to develop and/or evaluate the serological method. In 57% of all the assigned farms, based on serological screening (~ mean SIP-ratio\u27s), there is \u27firm evidence\u27 by bacteriological isolation. This suggests that a sufficient correlation is achieved at herd level in the first stage of the Salmonella Action Plan