Study of in vivo catheter biofilm infections using pediatric central venous catheter implanted in rat

International audienceVenous access catheters used in clinics are prone to biofilm contamination, contributing to chronic and nosocomial infections. So far, biofilm physiology was mostly studied in vitro, due to a relative lack of clinically relevant in vivo models. Here, we provide a relevant protocol of totally implantable venous access port (TIVAP) implanted in rats. This model recapitulates all phenomena observed in clinic and allows studying bacterial biofilm development and physiology. After TIVAP implantation and inoculation with luminescent pathogens, in vivo biofilm formation can be monitored in situ and biofilm biomass can be recovered from contaminated TIVAP and organs. We used this protocol to study host responses to biofilm-infection, to evaluate preventive and curative anti-biofilm strategies, and to study fundamental biofilm properties. For this procedure, one should expect ~3h00 of hands-on time including the implantation in one rat followed by in situ luminescence monitoring and bacterial load estimation

Yeast Biofilms

Yeast biofilms are an escalating clinical problem, which affect both the healthy and immunocompromised, and are related to significant rates of mortality within hospitalized patients. Candida albicans is the most notorious yeast biofilm former and as a result the most widely studied; however, other Candida species and yeasts such as Cryptococcus neoformans are also implicated in biofilm-associated infections. Yeast biofilms have distinct developmental phases, including adhesion, colonization, maturation and dispersal, which have been examined utilizing various in vitro and in vivo model systems. Furthermore, the complex molecular events governing biofilm development are slowly being elucidated, including the role of quorum sensing. Clinically, biofilms act as reservoirs for systemic infection, and also induce localized pathology and tissue damage. However, the key virulence factor is their recalcitrance to antifungal therapy. This chapter will discuss our current understanding of the role that yeast biofilms play in the clinical setting