Characterization of the Bacterial Biofilm Communities Present in Reverse-Osmosis Water Systems for Haemodialysis.

Juan-Pablo Cuevas,Ruben Moraga,Ítalo Fernandez,Cristian Valenzuela,Carlos T Smith,Víctor L Campos,Apolinaria García,Paulina Aguayo,Kimberly Sánchez-Alonzo

doi:10.3390/microorganisms8091418

Juan-Pablo Cuevas, Ruben Moraga + Show 7 more

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https://doi.org/10.3390/microorganisms8091418

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Journal: Microorganisms	Publication Date: Sep 15, 2020
Citations: 7	License type: CC BY 4.0

Affiliation: University of Concepción, Arturo Prat University

Abstract

Biofilm in reverse osmosis (RO) membranes is a common problem in water treatment at haemodialysis facilities. Bacteria adhere and proliferate on RO membranes, forming biofilms, obstructing and damaging the membranes and allowing the transfer of bacteria and/or cellular components potentially harmful to the health of haemodialysis patients. Our aim was to characterize the bacterial community associated to biofilm of RO membranes and to identify potentially pathogenic bacteria present in the haemodialysis systems of two dialysis centres in Chile. The diversity of the bacterial communities present on RO membranes and potable and osmosed water samples was evaluated using Illumina sequencing. Additionally, bacteria from potable water, osmosed water and RO membrane samples were isolated, characterized and identified by Sanger’s sequencing. The molecular analyses of metagenomics showed that the phyla having a greater relative abundance in both dialysis centres were Proteobacteria and Planctomycetes. Pseudomonas, Stenotrophomonas, Agrobacterium, Pigmentiphaga, Ralstonia, Arthrobacter, Bacteroides and Staphylococcus were bacterial genera isolated from the different samples obtained at both haemodialysis centres. Pseudomonas spp. was a bacterial genus with greater frequency in all samples. Pseudomonas and Staphylococcus showed higher levels of resistance to the antibiotics tested. Results demonstrated the presence of potentially pathogenic bacteria, showing resistance to antimicrobials on RO membranes and in osmosed water in both dialysis centres studied.

Highlights

Since the incidence of chronic renal failure is increasing around the world, the number of individuals requiring treatment for end-stage renal disease is rising [1]
The presence of multi-drug resident bacteria and persistent bacteria in biofilm has been poorly studied, and considering the risk they signify to patients, the aim of the present work was to characterize the bacterial communities associated to the water and reverse osmosis (RO) membranes from two haemodialysis treatment centres and to identify potentially pathogenic bacteria and to determine their resistance to antimicrobials
The results showed that the bacterial strains belonging to the genera Pseudomonas and Staphylococcus showed higher levels of resistance to the antibiotics tested (Table 3)

Summary

Introduction

Since the incidence of chronic renal failure is increasing around the world, the number of individuals requiring treatment for end-stage renal disease is rising [1]. Patients undergoing HD are subjected to large volumes of dialysis fluid (approximately 120 L) in a single dialysis treatment [2]. Considering the repeated large volumes of water each patient is subjected to, ensuring the necessary quality of dialysate solution is a vital aspect for a safe HD because chemical, bacterial and associated endotoxin and bacterial debris contamination can threaten the health of a patient requiring this treatment [3]. Dialysis patients often have additional comorbidities (e.g., diabetes, hypertension and cardiovascular disease) making them more vulnerable to adverse outcomes [4]. The Association for the Advancement of Medical Instrumentation (AAMI) recommendations for conventional dialysis water includes its microbiological quality, requiring

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