Mixed biofilms induced in hemodialysis fluids

• Grant number: 16/24330-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): March 01, 2017
• Effective date (End): December 31, 2017
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Regina Helena Pires
• Grantee: Matheus Torres Branca
• Host Institution: Pró-Reitoria Adjunta de Pesquisa e Pós-Graduação. Universidade de Franca (UNIFRAN). Franca , SP, Brazil

Abstract

Hemodialysis is a process by which the patient undergoes extracorporeal filtration of their blood to remove impurities, replacing the kidney, since they no longer perform their function in the body. This procedure is performed by a machine in order to establish a circuit where a specific liquid (dialysate) flows to provide the exchange of substances with the blood. However, the dilution of concentrated solutions of salts (acid and basic solution) in chlorine-free water to make the dialysate makes this system susceptible to microbial contamination. The colonization of the piping of the water distribution system and cannulae of dialysis machines by microorganisms allows the formation of biofilms which are formed into microbial conglomerates that adhere firmly to a solid biotic or abiotic surfaces. Such biofilms can be formed by a single species (monospecies biofilm), organisms of the same genus or even different microbial kingdoms (multispecies or mixed biofilms). Thus, this work proposes to evaluate the ability of the formation of double-species biofilms composed of bacteria (Pseudomonas aeruginosa, Escherichia coli and Staphylococcus epidermidis) and fungi (Aspergillus niger, Aspergillus terreus, Fusarium oxysporum, Penicillium bravicompactum and Penicillium spp.). In addition, was investigated the ability to form triple-species biofilms between: C. parapsilosis /one of the bacteria and a filamentous fungus mentioned above. Isolates previously recovered from the water circuit and machine cannulas from a hemodialysis facility will be used. The biofilms will be formed in polystyrene microplates (96 wells), using culture medium, dialysate (with and without glucose) and its constituent solutions (acidic and basic). The biofilms' biomass will be quantified by the crystal violet methodology. The scanning electron microscopy will show the morphology and topography of biofilms. The study may contribute to the expansion of the knowledge associated with mono- or multi-species biofilm formed in the dialytic environment. In addition, actions inherent to surveillance aiming at identifying potential risks to human health may trigger corrective and preventive actions with the aim of promoting the health of the population (AU)