Protein truncating variants of colA in clostridium perfringens type G strains

Extracellular matrix (ECM) degrading enzymes produced by Clostridium perfringens may play an important role during the initial phases of avian necrotic enteritis by facilitating toxin entry in the intestinal mucosa and destruction of the tissue. C. perfringens is known to produce several ECM-degrading proteases, such as kappa toxin, an extracellular collagenase that is encoded by the colA gene. In this study, the colA gene sequence of a collection of 48 C. perfringens strains, including pathogenic (i.e. toxinotype G) and commensal (i.e. toxinotype A) chicken derived strains and strains originating from other host species, was analyzed. Although the colA gene showed a high level of conservation (>96% nucleotide sequence identity), several gene variants carrying different nonsense mutations in the colA gene were identified, leading to the definition of four truncated collagenase variant types (I-IV). Collagenase variant types I, III and IV have a (nearly) complete collagenase unit but lack parts of the C-terminal recruitment domains, whereas collagenase variant types II misses the N-terminal part of collagenase unit. Gene fragments encoding a truncated collagenase were mainly linked with necrotic enteritis associated C. perfringens type G strains with collagenase variant types I and II being the most prevalent types. Gelatin zymography revealed that both recombinant full-length and variant type I collagenase have active auto-cleavage products. Moreover, both recombinant fragments were capable of degrading type I as well as type IV collagen, although variant type I collagenase showed a higher relative activity against collagen type IV as compared to full-length collagenase. Consequently, these smaller truncated collagenases might be able to break down collagen type IV in the epithelial basement membrane of the intestinal villi and so contribute to the initiation of the pathological process leading to necrotic enteritis

Development of a cost efficient platform for the industrial manufacturing of pluripotent stem cell derived products for cell therapy: Cell expansion is the starting point

The development of stem cell-derived allogeneic therapeutics requires manufacturing processes able to generate high-density cultures of pluripotent stem cells (PSCs) to be further differentiated to target somatic cells. The Cell Plasticity platform of The Cell and Gene Therapy Catapult (CGT) is a core program that focuses on the cost efficient development of bioprocesses for the industrial manufacture of PSC-derived products in 2D and 3D culture systems. We started this program by establishing banks of PSCs adapted to defined culture systems and used conventional analytical techniques to characterise the cells to industry standards. Defined media were evaluated for the expansion of induced pluripotent stem cells (iPSC) in adherent culture. Scale-down high-throughput tools along with Design of Experiment methodology have been employed to establish a baseline process for the expansion of PSC as cellular aggregates in stirred-suspension culture and targeting cell yield \u3e 5x106 viable cells/mL. We are currently investigating bioengineering parameters for scale-up and evaluating cell retention devices for the dissociation of PSC aggregates in a closed and automated fashion. In parallel, a framework of analytical assays comprising imaging, flow-cytometry and gene expression is under development for process monitor and control using a proprietary multi-parametric analysis approach

L’impact des stratégies de coping sur le bien-être des travailleurs en lien avec l’interface travail-famille : analyse sous l’angle de la théorie de la sélectivité socio-émotionnelle

L’objectif de ce mémoire est de mieux comprendre le bien-être au travail et l’utilisation des stratégies de coping en lien avec l’interface travail-famille et ce tout au long de la carrière professionnelle. Ce mémoire s’inscrit dans le cadre de la théorie de la sélectivité socio-émotionnelle de Carstensen. Plus précisément, cela permettra d’étudier le processus lié au vieillissement au travail à l’aide du concept de la perspective temporelle future professionnelle. En effet, la perspective temporelle professionnelle permet d’expliquer la perception qu’un travailleur a de son avenir au travail. De plus, la théorie de la sélectivité socio-émotionnelle permettra de mieux comprendre les stratégies de coping utilisées dans une situation de travail stressante pour le travailleur. Il semble que les stratégies varient en fonction des objectifs poursuivis par l’individu et de sa perspective temporelle future. Enfin, l’impact des conflits de l’interface travail-famille sur la vie d’un travailleur peut aussi être influencé par sa perspective temporelle future. La théorie de la sélectivité socio-émotionnelle mettra donc en lumière les conflits de l’interface travail-famille qui peuvent influencer la vie d’un travailleur.Master [120] en sciences psychologiques, Université catholique de Louvain, 201

Associations between a decreased veterinary antimicrobial use and resistance in commensal Escherichia coli from Belgian livestock species (2011–2015)

In this study the possible association between antibiotic use and resistance was explored, focusing on commensal Escherichia coli from livestock (veal calves, young beef cattle, pigs and broiler chickens) in Belgium between 2011 and 2015. A continuous decreasing trend in antibiotic use was observed for all classes, except for the phenicols. Antibiotic resistance of commensal E. coli significantly decreased for several of the tested antibiotics in all livestock species. A more rapidly reverted resistance was seen to 3th/4th generation cephalosporins and fluoroquinolones. Moderate to strong correlations between antibiotic use and resistance were found, except for antibiotic resistance to chloramphenicol and gentamicin and the use of the corresponding antibiotic class. Yet, total antibiotic use was positively correlated with chloramphenicol resistance, showing the potential importance of co-selection for chloramphenicol resistance. These results suggest that national antimicrobial usage reduction campaigns have beneficial effects on the overall resistance levels. Analyses were performed on small datasets, though, and care must be taken while making inference. For more detailed analysis, antibiotic use data at an animal species level are required

Disseminated infection with Mycobacterium tilburgii in a male immunocompromised patient

Mycobacterium tilburgii is a nonculturable nontuberculous mycobacterium identifiable only by molecular methods. We report a case of disseminated M. tilburgii infection illustrating the importance of 16S rRNA gene sequencing to determine the responsible mycobacterial pathogen and the difficulties in tailoring antimycobacterial treatment in the absence of a culturable organism

Study on cross-border health services: enhancing information to patients - final report

status: Published onlin

NanI sialidase contributes to toxin expression and host cell binding of Clostridium perfringens type G strain CP56 in vitro

Necrotic enteritis, caused by NetB producing Clostridium perfringens type G strains, is a globally important poultry disease. An initial step in the pathogenesis of necrotic enteritis is the colonization and degradation of the intestinal mucus layer, a process in which C. perfringens sialidases - such as NanI sialidase - may play an important role. Sialidases cleave terminal sialic acid from complex carbohydrates on glycoconjugates, such as mucins. This study shows that NE-associated C. perfringens strain CP56 is able to use sialic acid (Neu5Ac) as a carbon source for bacterial growth. It is shown that supplementation of Neu5Ac in the growth medium does not only induce the production of extracellular sialidases of strain CP56, but also increases the production of both alpha toxin and NetB toxin. Moreover, it was found that pre-treating avian hepatocellular carcinoma cells (LMH cells) with the recombinant NanI sialidase increases the adherence of C. perfringens type G strain CP56 to these cells. As such, the data suggest an important role for sialidases in the pathogenesis of the disease