Microbial ecology of haemodialysis water
Speaker: Margarita Gomila* - Department of Biology of the Universitat de les Illes Balears
The microbiological quality of water is of crucial importance in the renal replacement therapy of patients undergoing haemodialysis. The water used to prepare haemodialysis fluid constitutes an oligotrophic habitat in which complex bacterial communities with a high level of diversity can develop. The microorganisms present in water can form biofilms on filters, tanks and water pipes, which hinders their elimination and facilitates their persistence. Some of these bacteria are potentially pathogenic, may be the source of nosocomial infections, and act as a reservoir and medium for the dissemination of antibiotic resistance genes. In addition, some microbial products resulting from the lyses and death of microorganisms, as well as "nanobacteria", can pass through the haemodialysis filters, causing inflammatory reactions in patients with chronic renal failure. The presence of bacteria and bacterial-derived products (i.e., endotoxins, sphingolipids, and oligonucleotides) can contribute to silent chronicinflammation, secondary amyloidosis, pyrogenic reactions and anemia. The aim of the work is to expand our knowledge of the bacteria responsible of the biofilm in haemodialysis waters (Gomila et al., 2005, 2006), by using next-generation sequencing methodologies and new strategies for identifying bacterial isolates. The main objective is to characterize the microbial community present in the haemodialysis water used to reconstitute the dialysis fluid at the hospital. The ultimate goal is the knowledge of the bacteria involved and the conditions that favour its development, which will allow the establishment of methodologies for their monitoring and removal, getting a better haemodialysis water quality and contributing to the quality of life of persons subjected to this treatment.
The results obtained show that bacterial community present in the dialysis water is very complex, with microorganisms highly diverse and adapted to the oligotrophic habitat, not usually detected routinely in clinical microbiology laboratories.
* Margarita Gomila is a postdoctoral researcher at the Department of Biology of the Universitat de les Illes Balears where she got her PhD in Biological Science. She has participated in several research projects in the field of molecular microbial ecology, particularly in the study of the microbiota present in aquatic habitats. She has expertise on the analysis of sewage water, the impact of water treatment plants effluents into the marine environment and in the microbiological, physical and chemical analysis of wastewater treatment plants, and the effectiveness of different treatments applied to these waters. She has opened a pioneering research line in the analysis of pure hospital waters, applying molecular techniques to the study of haemodialysis water. She is currently working in a metagenomics project, using NGS methodologies applied to hospital haemodialysis waters, aiming at characterizing the organisms present, identifying their role in the microbial community and analyzing bacterial genomes for ultrafast diagnoses purposes.