Evaluation of Surface Microtopography Engineered by Direct Laser Interference for Bacterial Anti-Biofouling

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Modification of the biomaterial surface topography is a promising strategy to prevent bacterial adhesion and biofilm formation. In this study, we use direct laser interference patterning (DLIP) to modify polystyrene surface topography at sub-micrometer scale. The results revealed that three-dimensional micrometer structures have a profound impact on bacterial adhesion. Thus, line- and pillar-like patterns enhanced S. aureus adhesion, whereas complex lamella microtopography reduced S. aureus adhesion in static and continuous flow culture conditions. Interestingly, lamella-like textured surfaces retained the capacity to inhibit S. aureus adhesion both when the surface is coated with human serum proteins and when the material is implanted subcutaneously in a foreign-body associated infection model.J. Valle was supported by Spanish Ministry of Science and Innovation “Ramón y Cajal” contract. This research was supported by grants AGL2011-23954 and BIO2011-30503-C02-02 from the Spanish Ministry of Economy and Competitivity and IIQ14066. RI1 from Innovation Department of the Government of Navarra. A. Lasagni, D. Langhenirich, and R. Helbig thank the Deutsche Forschungsgemeinschaft (DFG) for the financial support of the project “Mechanically stable anti-adhesive polymer surfaces” (LA-2513 4-1).Peer Reviewe

Evaluation of a Salmonella strain lacking the secondary messenger C-di-GMP and RpoS as a live oral vaccine

Salmonellosis is one of the most important bacterial zoonotic diseases transmitted through the consumption of contaminated food, with chicken and pig related products being key reservoirs of infection. Although numerous studies on animal vaccination have been performed in order to reduce Salmonella prevalence, there is still a need for an ideal vaccine. Here, with the aim of constructing a novel live attenuated Salmonella vaccine candidate, we firstly analyzed the impact of the absence of cyclic-di-GMP (c-di-GMP) in Salmonella virulence. Cdi- GMP is an intracellular second messenger that controls a wide range of bacterial processes, including biofilm formation and synthesis of virulence factors, and also modulates the host innate immune response. Our results showed that a Salmonella multiple mutant in the twelve genes encoding diguanylate cyclase proteins that, as a consequence, cannot synthesize c-di-GMP, presents a moderate attenuation in a systemic murine infection model. An additional mutation of the rpoS gene resulted in a synergic attenuating effect that led to a highly attenuated strain, referred to as ΔXIII, immunogenic enough to protect mice against a lethal oral challenge of a S. Typhimurium virulent strain. ΔXIII immunogenicity relied on activation of both antibody and cell mediated immune responses characterized by the production of opsonizing antibodies and the induction of significant levels of IFN-γ, TNF-α, IL-2, IL-17 and IL-10. ΔXIII was unable to form a biofilm and did not survive under desiccation conditions, indicating that it could be easily eliminated from the environment. Moreover, ΔXIII shows DIVA features that allow differentiation of infected and vaccinated animals. Altogether, these results show ΔXIII as a safe and effective live DIVA vaccine.SB is a predoctoral fellow from the Public University of Navarra. CG and BG are recipients of a postdoctoral contract under Grants IIM 13329.RI1 and BIO2011-30503-C02-02, respectively. This work was supported by grant IIM 13329.RI1 from the Departamento de Innovación, Empresa y Empleo, Government of Navarra and grants BIO2011-30503-C02-02 and BIO2014-53530-R from the Spanish Ministry of Economy and Competitiveness.Peer Reviewe

The epidermal growth factor receptor ligand amphiregulin participates in the development of mouse liver fibrosis

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