Reflexive Views of Virtual Communities of Practice among Informal and Formal Caregivers of People with a Dementia Disease.

Knowledge seems to mitigate the consequences of dementia and new educational strategies are required. This study aimed to qualitatively explore the reflexive views and experiences of virtual Communities of Practice (vCoP) among informal and formal caregivers of people with dementia and explore vCoP as a tool for learning and knowledge development. Data were collected in a sequence of virtual workshops and analyzed and synthesized using thematic analysis. For the informal caregivers, one main theme emerged: Learning and support, comprising three subthemes: Strategies for learning; Creating emotional support; and in need of professional support. Among formal caregivers, one main theme emerged: Professional development, comprising two subthemes: Sharing and gaining knowledge and Knowledge as a professional tool. vCoP and collaborative learning using an educational platform seem to support learning and professional development among informal and formal caregivers, respectively. As a collaborative, virtual activities seem to provide practical and emotional support and promote professional development; vCoP seem to have the potential to promote the resilience and sustainability of care. Further research is necessary to gain an understanding of the effects of Communities of Practice (CoP) and vCoP and their successful implementation in care practices as well as the potential of using CoP in continuing professional development, CPD.

Cytokeratin 18 interacts with the enteropathogenic Escherichia coli secreted protein F (EspF) and is redistributed after infection.

Enteropathogenic Escherichia coli (EPEC) pathogenesis requires the delivery of effector proteins into host cytosol by a type III secretion system. The effector protein EspF, while critical for disruption of epithelial barrier function through alteration of tight junctions, is not required for bacterial viability or attachment. Yeast two-hybrid analyses revealed host intermediate filament (IF) protein cytokeratin 18 (CK18) as an interacting partner of EspF. This was confirmed by co-immunoprecipitation of extracts from EPEC-infected epithelial cells. EPEC infection increased detergent-soluble CK18 amounts without significantly altering CK18 expression. The adaptor protein 14-3-3 binds to CK18 and modulates its solubility. EPEC infection promoted CK18/14-3-3 interactions, corresponding to the increase of CK18 in the soluble fractions. 14-3-3 also co-immunoprecipitated with EspF, suggesting that CK18, 14-3-3 and EspF may form a complex in infected cells. The 14-3-3zeta isoform was co-immunoprecipitated with CK18, suggesting the involvement of specific signalling pathways. Immunofluorescence studies revealed a dramatic alteration in the architecture of the IF network in EPEC-infected epithelial cells. IF fragmentation, evident at 2 h post infection, progressed to a collapse of this network at later time points. The secretion mutant (DeltaescN) failed to alter CK18 solubility and IF morphology, while deletion of espF partially impaired the ability of EPEC to induce CK18 modifications. These results suggest that modifications in 14-3-3 interactions and IF network, modulated by type III secreted proteins, may be an important step in EPEC pathogenesis.

Comparative analysis of EspF from enteropathogenic and enterohemorrhagic Escherichia coli in alteration of epithelial barrier function.

Enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic E. coli (EHEC) are related intestinal pathogens that harbor highly similar pathogenicity islands known as the locus of enterocyte effacement (LEE). Despite their genetic similarity, these two pathogens disrupt epithelial tight junction barrier function with distinct kinetics. EHEC-induced reduction in transepithelial electrical resistance (TER), a measure of barrier function disruption, is significantly slower and more modest in comparison to that induced by EPEC. The variation in bacterial adherence only partially accounted for these differences. The LEE-encoded effector protein EspF has been shown to be critical for EPEC-induced alterations in TER. EspF from both EPEC and EHEC is expressed and secreted upon growth in tissue culture medium. The mutation of EHEC cesF suggested that the optimal expression and secretion of EHEC EspF required its chaperone CesF, as has been shown for EPEC. In contrast to EPEC espF and cesF, mutation of the corresponding EHEC homologs did not dramatically alter the decrease in TER. These differences could possibly be explained by the presence of additional espF-like sequences (designated U- and M-espF, where the letter designations refer to the specific cryptic prophage sequences on the EHEC chromosome closest to the respective genes) in EHEC. Reverse transcription-PCR analyses revealed coordinate regulation of EHEC U-espF and the LEE-encoded espF, with enhanced expression in bacteria grown in Dulbecco-Vogt modified Eagle's medium compared to bacteria grown in Luria broth. Both EHEC espF and U-espF complemented an EPEC espF deletion strain for barrier function alteration. The overexpression of U-espF, but not espF, in wild-type EHEC potentiated the TER response. These studies reveal further similarities and differences in the pathogenesis of EPEC and EHEC.