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Extra-intestinal pathogenic Escherichia coli (ExPEC) belong to a critical priority group of antibiotic resistant pathogens. ExPEC establish gut reservoirs that seed infection of the urinary tract and bloodstream, but the mechanisms of gut colonisation remain to be properly understood. Ucl fimbriae are attachment organelles that facilitate ExPEC adherence. Here, we investigated cellular receptors for Ucl fimbriae and Ucl expression to define molecular mechanisms of Ucl-mediated ExPEC colonisation of the gut. We demonstrate differential expression of Ucl fimbriae in ExPEC sequence types associated with disseminated infection. Genome editing of strains from two common sequence types, F11 (ST127) and UTI89 (ST95), identified a single nucleotide polymorphism in the ucl promoter that changes fimbriae expression via activation by the global stress-response regulator OxyR, leading to altered gut colonisation. Structure-function analysis of the Ucl fimbriae tip-adhesin (UclD) identified high-affinity glycan receptor targets, with highest affinity for sialyllacto-N-fucopentose VI, a structure likely to be expressed on the gut epithelium. Comparison of the UclD adhesin to the homologous UcaD tip-adhesin from Proteus mirabilis revealed that although they possess a similar tertiary structure, apart from lacto-N-fucopentose VI that bound to both adhesins at low-micromolar affinity, they recognize different fucose- and glucose-containing oligosaccharides. Competitive surface plasmon resonance analysis together with co-structural investigation of UcaD in complex with monosaccharides revealed a broad-specificity glycan binding pocket shared between UcaD and UclD that could accommodate these interactions. Overall, our study describes a mechanism of adaptation that augments establishment of an ExPEC gut reservoir to seed disseminated infections, providing a pathway for the development of targeted anti-adhesion therapeutics.

El Dr. Carlos Alberto Arango Cálad, Profesor Titular Jubilado de la Universidad del Valle, cursó su carrera de psicología en la Universidad Nacional de Colombia, con sede en Bogotá (1978), y su máster iberoamericano en psicología comunitaria (1993) y su doctorado en psicología social y de las organizaciones (1995) en la Universitat de Valencia, España. En 2008, recibió un reconocimiento como pionero de la psicología comunitaria en Colombia por parte del Colegio Colombiano de Psicólogos. Aunque se encuentra jubilado desde hace unos 15 años, continúa con su labor en el área de psicología comunitaria, psicología y pedagogía de la convivencia, participación y ciudadanías incluyentes a través de la metodología de la Investigación-Acción-Participativa. Se ha enfocado, además, a comprender el rol del psicólogo comunitario y las estrategias de intervención en red y construcción de políticas públicas. Actualmente, se dedica a gestionar y acompañar el proceso de la Expedición Psicosocial Colombiana y la Red Colombiana de Psicología Comunitaria. Además, imparte cursos de posgrado en diversas universidades. En esta entrevista, nos habla de su amplia trayectoria en psicología comunitaria y sobre la formación para intervención psicosocial en la educación superior en Colombia.

Incentive-based mechanisms, such as payments for ecosystem services (PES) are increasingly being employed to encourage adoption of biodiversity conservation practices in agriculture. Farmers’ participation in a PES depends – amongst other factors – on their interactions with previous programs and schemes. This research analyses how the institutional characteristics and interactions of incentive-based mechanisms shape the type of farmers’ participation and the achievement of desired socio-ecological outcomes. This research focusses on the institutional frameworks of two programs in the Province of Quebec, Canada: the ‘Prime-Vert’ Program (public agri-environment scheme) and the ‘Alternative Land Use Services’ (ALUS) initiative (a privately-funded “PES” scheme). The institutional prescriptions of these two programs were examined and compared through the lenses of the Institutional Analysis and Development framework. We reveal the impact of the institutional framework on farmers’ participation by assessing the degree of farmers’ engagement in the implementation and management of schemes. Our results showed a strong dependence of the private PES on the public scheme, rendering both programs ultimately managed under the remit of the provincial government. While the complementarity of both programs diversifies sources of funding for farmers, the presence of rigid rules governing these incentives tend to treat farmers as passive beneficiaries of a network of centralized subsidies which they have little control over. This compromises farmers’ autonomy as the rigidity of rules impedes any attempt to achieve active participation in the design and implementation of agri-environmental practices.

Factitious ulcers are characterized by self-inflicted lesions with multifactorial origin. These lesions are frequently found in head, neck, and hands. This report shows a 6-year-old boy diagnosed with factitious oral ulcers that occurred after the self-biting of buccal vestibule and nail-scratching of gingival tissue. Clinically, a significant swelling was observed, hard on palpation, located at the right lower third of the face, next to the posterior area of the mandible. In the intraoral examination, ulcers at different healing stages were noted on the swelling area. During the anamnesis, the father reported a change in his familial structure that triggers psychological stress, providing the clues to the presumptive diagnosis of factitious oral ulcers. We prescribed the topical use of Gingilone® three times a day to control the local pain and inflammation. At 7-day follow-up, we noticed the reduction of extraoral swelling and the initial healing of the ulcers. The presumptive diagnosis was confirmed at 30-day follow-up, with the lasting remission of oral lesions. The treatments of factitious oral ulcers should be individually tailored for each patient, focused on a multidisciplinary approach, including psychotherapy and periodic clinical control. To the best of our knowledge, gaps of evidence lead to the lack of standardized clinical protocols on this issue.