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The freshwater environment is suitable for nontuberculous mycobacteria (NTMs) growth. Their high adaptability represents a considerable risk for sanitary water systems, which are a potential vector for NTMs transmission. This study investigated the occurrence of NTMs, such as Mycobacterium saskatchewanense, in hospital water systems to support the surveillance and control of potentially pathogenic NTMs. We analyzed 722 ultrapure dialysis fluid samples from Emilia Romagna Dialysis Services. Among these, 35 samples were found to be positive for M. saskatchewanense. The strains were characterized using whole-genome sequencing (WGS) and variability analysis was carried out along the whole M. saskatchewanense genome. This investigation revealed the exclusive presence of M. saskatchewanense in these dialysis machines, with low genetic variability among all strains (with a low number of different alleles: <15). The strong similarity among the strain groups was also confirmed in the WGS-based ML tree, with very few significant nodes, and no clusters were identified. This research highlights the necessity of implementing surveillance protocols and investigating any potential link to human infections, as well as stressing the urgency of enhancing surveillance and infection control measures. [ABSTRACT FROM AUTHOR]

This study aims to investigate the presence of Free-Living Amoebae (FLA), particularly Acanthamoeba spp., in diverse water systems and body fluids within a hospital. Water and body fluid samples were collected from various locations. Cultivation of FLA was performed using Non-Nutrient Agar (NNA) culture with Escherichia coli, and microscopic observations after staining. Microscopic observations revealed the presence of Acanthamoeba spp. in pre-dialysis tank water and dental flush water samples. The identification of Acanthamoeba in specific water sources underscores the importance of continuous monitoring and preventive strategies to mitigate potential health risks.

The freshwater environment is suitable for nontuberculous mycobacteria (NTMs) growth. Their high adaptability represents a considerable risk for sanitary water systems, which are a potential vector for NTMs transmission. This study investigated the occurrence of NTMs, such as Mycobacterium saskatchewanense, in hospital water systems to support the surveillance and control of potentially pathogenic NTMs. We analyzed 722 ultrapure dialysis fluid samples from Emilia Romagna Dialysis Services. Among these, 35 samples were found to be positive for M. saskatchewanense. The strains were characterized using whole-genome sequencing (WGS) and variability analysis was carried out along the whole M. saskatchewanense genome. This investigation revealed the exclusive presence of M. saskatchewanense in these dialysis machines, with low genetic variability among all strains (with a low number of different alleles:

The water treatment process is a vital factor for hemodialysis (HD) patients. This study aimed to assess the degree of contamination of HD water by bacteria at the HD center of Mohammedia, Morocco, in addition to evaluating the antimicrobial resistance of isolated bacteria. Fifty-four water samples were taken, the appropriate cultures were used to isolate the pathogenic bacteria, which were identified biochemically and molecularly by 16S RNA sequencing. Their susceptibility to antimicrobial drugs was determined by the disk diffusion method. Approximately 5.5% of water samples were above the norm. The isolated bacteria that colonized the HD systems were mostly Gram-negative bacilli, such as Stenotrophomonas maltophilia, Pseudomonas spp., and Burkholderia cepacian. Results of the antibiotics test showed remarkable resistance levels. Among Pseudomonas spp. and S. maltophilia, 10 strains were classified as multidrug-resistant (MDR), and 4 as extensively drug-resistant (XDR). The diversity of bacterial strains isolated in the water used for HD treatments, and their worrying resistance levels pose a significant risk to patients. For these reasons, an urgent need for periodic microbiological monitoring of water after each treatment step must be applied, and the treatment process should also be optimized. HIGHLIGHTS Overall, the water quality in the Mohammedia HD center does comply with the minimum requirement of hemodialysis water.; Bacteria with pathogenic potential in hemodialysis water.; Bacteria with high antimicrobial resistance.;

Water quality for dialysis fluid is an important consideration for dialysis patients. As a result, strict monitoring of water quality is required to avoid complications and ensure the safety and health of patients. The current study aimed to determine the water quality used in hemodialysis treatment centers. Twenty water samples were collected and analyzed from three hospitals in Baghdad's medical city over four seasons. Counts of bacteria and chemical contaminants were determined in raw and dialysis water from each of four dialysis centers. After collecting samples, bacteriological and chemical analyses were performed in the laboratory. Results show that the quality of dialysis water fluctuates, making it unacceptable when compared to international standards. Bacterial counts were above the maximum value of 100 CFU/ml in 50% of the samples tested. Chemical analysis showed that the dialysis water quality suffers from elevated free chlorine concentrations in some dialysis centers. Also, there were no significant differences between the measured parameters in the dialysis water at four treatment centers during the study period at p < 0.05. Hemodialysis centers require constant monitoring, maintenance, and the development of water treatment systems to ensure optimum water quality. Additional disinfection is essential in order to prevent bacterial growth and biofilm formation. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the occurrence of fungi in dialysis water and dialysate, in addition to evaluating the susceptibility to antifungals and the biofilm production capacity of isolated microorganisms. The samples were collected in three hemodialysis units in Bauru (Brazil), every 15 days (July 2017–June 2018) at post-reverse osmosis, reuse, and dialysate points. The fungi were isolated by spread plate on Sabouraud dextrose agar. Filamentous fungi were phenotypically identified and yeasts were subjected to molecular evaluation of the ITS region. Susceptibility test to antifungals was carried out by the broth microdilution method and biofilm production capacity was evaluated in microtiter plates using crystal violet staining. Fungi were isolated in 52/216 (24.1%) samples, with an average count of 16.3 (10–40) CFU/mL. Overall, 61 microorganisms were identified, with 54 (88.5%) filamentous fungi and 7 (11.5%) yeasts. The main genera included were Penicillium, Cladosporium, Scedosporium, Rhinocladiella, Fusarium, and Emmonsia. Most isolates showed high values of minimum inhibitory concentration for 5-flucytosine and fluconazole and 35/45 (77.8%) isolates were classified as strong producers of biofilm. In order to increase the safety of the dialysis process, the adoption of control measures and monitoring of fungi in hemodialysis fluids is suggested. HIGHLIGHTS Fungi with pathogenic potential in hemodialysis fluids.; Fungi with low susceptibility to antifungals.; Fungi capable of producing biofilm.;

Hemodialysis (HD) patients are exposed to large volumes of water and any contamination may cause potential health risks. A multicenter study was aimed at evaluating and comparing the physicochemical, bacterial quality and endotoxin levels of dialysis water of eight HD centers consisting of seven in Algeria and one center in France. A total of 576 and 1,440 samples were examined for physico-chemical and bacterial analysis respectively and 192 samples for endotoxins, from April 2016 to March 2019. The results indicated that the dialysis water quality in some centers did not comply with the international standards for calcium, potassium, total and free chlorine, lead, cadmium, copper, and aluminum. Surprisingly, the conductivity was significantly higher than the allowed limits among all centers. Regarding the efficiency of the dialysis water treatment system, significant differences (p < 0.05) were recorded between tap water and dialysis water samples with the exception for cadmium in one of the centers where a low rejection rate of 8% was obtained. All removal rates were higher than 50% except for two participant centers. Total microbial counts at 22°C were present at levels higher than the maximum value of 100 CFU/mL in 75% of samples for one center while endotoxin levels were below the international standards (<0.25 IU/mL) in =65% of dialysis water samples. These data imply possible risks to hemodialysis patients and more efforts are needed to improve water quality management practices in dialysis centers. National standards for dialysis water should be developed. [ABSTRACT FROM AUTHOR]

Aims: To evaluate the physicochemical and microbiological quality of dialysis water and dialysate samples from haemodialysis centres. Methods and Results: Samples were fortnightly collected from three haemodialysis centres in Bauru City, Brazil, between July 2017 and June 2018, at the stages of post‐reverse osmosis, reuse and dialysate. Analyses included determination of conductivity, fluoride, nitrate and sulphate; test for total coliform bacteria; count of heterotrophic bacteria; count and identification of non‐fermenting gram‐negative bacilli (NFGNB); drug susceptibility test; biofilm formation capacity; and genetic similarity among some isolated NFGNB. Of the analysed samples, only 4/72 (5.6%) had conductivity values ≥10 mS/cm, 4/216 (1.9%) presented total coliforms and 1/216 (0.5%) had heterotrophic bacteria count >100 CFU/ml. NFGNB were isolated from 99/216 (45.8%) samples, and the major identified micro‐organisms included Herbaspirillum aquaticum/huttiense, Brevundimonas aurantiaca, Cupriavidus metallidurans, Pseudomonas aeruginosa and Ralstonia insidiosa. Isolates of P. aeruginosa and Burkholderia cepacia complex were sensitive to most antimicrobials and, together with isolates of Ralstonia insidiosa and Ralstonia pickettii, showed strong biofilm formation capacity. Some isolates expressed the same electrophoretic profile on pulsed‐field gel electrophoresis, indicating the persistence of bacterial clones in the systems over time. Conclusions: NFGNB were observed in several dialysis water and dialysate samples from all investigated centres, which may represent a risk to the health of patients. Significance and Impact of the Study: Regular inclusion of actions for NFGNB control and monitoring in haemodialysis fluids are suggested for greater safety of the dialytic process. [ABSTRACT FROM AUTHOR]

Abstract Background Ralstonia species are Gram-negative bacilli of low virulence. These organisms are capable of causing healthcare associated infections through contaminated solutions. In this study, we aimed to determine the source of Ralstonia mannitolilytica bacteraemia in affected patients in a haemodialysis unit. Methods Our laboratory noted an increase in cases of bacteraemia caused by Ralstonia mannitililytica between May and June 2016. All affected patients underwent haemodialysis at the haemodialysis unit of an academic hospital. The reverse osmosis filter of the haemodialysis water system was found to be dysfunctional. We collected water for culture at various points of the dialysis system to determine the source of the organism implicated. ERIC-PCR was used to determine relatedness of patient and environmental isolates. Results Sixteen patients were found to have Ralstonia mannitolilytica bacteraemia during the outbreak period. We cultured Ralstonia spp. from water collected in the dialysis system. This isolate and patient isolates were found to have the identical molecular banding pattern. Conclusions All patients were septic and received directed antibiotic therapy. There was 1 mortality. The source of the R. mannitolilytica infection in these patients was most likely the dialysis water as the identical organism was cultured from the dialysis water and the patients. The hospital management intervened and repaired the dialysis water system following which no further cases of R. mannitolilytca infections were detected. A multidisciplinary approach is required to control healthcare associated infections such as these. Routine maintenance of water systems in the hospital is essential to prevent clinical infections with R.mannitolilytica.

The water treatment process is a vital factor for hemodialysis (HD) patients. This study aimed to assess the degree of contamination of HD water by bacteria at the HD center of Mohammedia, Morocco, in addition to evaluating the antimicrobial resistance of isolated bacteria. Fiftyfour water samples were taken, the appropriate cultures were used to isolate the pathogenic bacteria, which were identified biochemically and molecularly by 16S RNA sequencing. Their susceptibility to antimicrobial drugs was determined by the disk diffusion method. Approximately 5.5% of water samples were above the norm. The isolated bacteria that colonized the HD systems were mostly Gram-negative bacilli, such as Stenotrophomonas maltophilia, Pseudomonas spp., and Burkholderia cepacian. Results of the antibiotics test showed remarkable resistance levels. Among Pseudomonas spp. and S. maltophilia, 10 strains were classified as multidrug-resistant (MDR), and 4 as extensively drug-resistant (XDR). The diversity of bacterial strains isolated in the water used for HD treatments, and their worrying resistance levels pose a significant risk to patients. For these reasons, an urgent need for periodic microbiological monitoring of water after each treatment step must be applied, and the treatment process should also be optimized. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the occurrence of fungi in dialysis water and dialysate, in addition to evaluating the susceptibility to antifungals and the biofilm production capacity of isolated microorganisms. The samples were collected in three hemodialysis units in Bauru (Brazil), every 15 days (July 2017-June 2018) at post-reverse osmosis, reuse, and dialysate points. The fungi were isolated by spread plate on Sabouraud dextrose agar. Filamentous fungi were phenotypically identified and yeasts were subjected to molecular evaluation of the ITS region. Susceptibility test to antifungals was carried out by the broth microdilution method and biofilm production capacity was evaluated in microtiter plates using crystal violet staining. Fungi were isolated in 52/216 (24.1%) samples, with an average count of 16.3 (10-40) CFU/mL. Overall, 61 microorganisms were identified, with 54 (88.5%) filamentous fungi and 7 (11.5%) yeasts. The main genera included were Penicillium, Cladosporium, Scedosporium, Rhinocladiella, Fusarium, and Emmonsia. Most isolates showed high values of minimum inhibitory concentration for 5-flucytosine and fluconazole and 35/45 (77.8%) isolates were classified as strong producers of biofilm. In order to increase the safety of the dialysis process, the adoption of control measures and monitoring of fungi in hemodialysis fluids is suggested. [ABSTRACT FROM AUTHOR]

Hemodialysis (HD) centers in Baghdad show high endotoxin concentrations. This reflects the removal of endotoxin was not under consideration in the dialysis units. The objective of this research is to evaluate several treatment processes to eliminate free endotoxin released from the ruptured cell wall of gram-negative bacteria in dialysis water. The studied treatment options include ultraviolet (UV), ultrafiltration membrane (UF), and zeta potential control was employed to improve the efficacy of the UF. Hybrid treatment was also considered by joining two or more of the above treatments. A lab-scale unit was built to implement the experiments and synthetic water (feed solution) was prepared with a known level of endotoxin (0.48 EU/mL). The test for Limulus amebocyte lysate was used to assess concentrations of endotoxin in treated water. The observed experimental results showed significant changes in the zeta potential of endotoxins when compared with both (UV alone) and (UV and UF). This kind of treatment reduced the concentration of endotoxin to 0.24 EU/mL by enhancing UF efficacy through zeta potential control and UV treatment. This study serves as a basis for applying physical treatment methods to the currently used water treatment techniques to produce dialysis water in compliance with the international dialysis fluid quality standards. [ABSTRACT FROM AUTHOR]

Background: Ralstonia species are Gram-negative bacilli of low virulence. These organisms are capable of causing healthcare associated infections through contaminated solutions. In this study, we aimed to determine the source of Ralstonia mannitolilytica bacteraemia in affected patients in a haemodialysis unit. Methods: Our laboratory noted an increase in cases of bacteraemia caused by Ralstonia mannitililytica between May and June 2016. All affected patients underwent haemodialysis at the haemodialysis unit of an academic hospital. The reverse osmosis filter of the haemodialysis water system was found to be dysfunctional. We collected water for culture at various points of the dialysis system to determine the source of the organism implicated. ERIC-PCR was used to determine relatedness of patient and environmental isolates. Results: Sixteen patients were found to have Ralstonia mannitolilytica bacteraemia during the outbreak period. We cultured Ralstonia spp. from water collected in the dialysis system. This isolate and patient isolates were found to have the identical molecular banding pattern. Conclusions: All patients were septic and received directed antibiotic therapy. There was 1 mortality. The source of the R. mannitolilytica infection in these patients was most likely the dialysis water as the identical organism was cultured from the dialysis water and the patients. The hospital management intervened and repaired the dialysis water system following which no further cases of R. mannitolilytca infections were detected. A multidisciplinary approach is required to control healthcare associated infections such as these. Routine maintenance of water systems in the hospital is essential to prevent clinical infections with R.mannitolilytica. [ABSTRACT FROM AUTHOR]

Hemodialysis centers in Baghdad show elevated concentrations of endotoxin. This reflects the inefficient treatment process used to purify dialysis water. The objective of this research is to evaluate several treatment processes to inactivate endotoxin concentration in dialysis water. The studied treatment options include utilizing ultrafiltration membrane (UF), disinfection with ozone (O3), and disinfection with hydrogen peroxide (H2O2). Hybrid treatment was also considered by joining two or more of the above treatment methods. A lab-scale unit was built to implement the experiments and synthetic water (feed solution) was prepared with a known value of endotoxin concentration (0.48 EU/ml). Limulus amebocyte lysate test was used to determine endotoxin concentrations in the treated water. The results showed that all the tested treatment methods resulted in reducing the levels of endotoxins and providing high purity dialysis water. However, the best treatment was achieved when using triple treatment (i.e. UF, O3, and H2O2). This combination reduced endotoxin concentration using the minimum feed of H2O2 at a significantly short contact time for oxidation agents (i.e., O3 and H2O2). Accordingly, it is important to change the design of the currently used water treatment units in Baghdad to produce dialysis water in compliance with the international dialysis water quality standards and save patients’ lives. [ABSTRACT FROM AUTHOR]

Background: Patients receiving haemodialysis are exposed to a large volume of dialysis fluid. The Italian Society of Nephrology (ISN) has published guidelines and microbial quality standards on dialysis water (DW) and solutions to ensure patient safety.Aim: To identify microbial and chemical hazards, and evaluate the quality of disinfection treatment in DW plants.Methods: In 2015 and 2016, water networks and DW plants (closed loop and online monitors) of nine dialysis wards of Italian hospitals, hosting 162 dialysis beds overall, were sampled on a monthly basis to determine the parameters provided by ISN guidelines. Chlorinated drinking water was desalinated by reverse osmosis and distributed to the closed loop which feeds all online monitors. Disinfection with peracetic acid was performed in all DW plants on a monthly basis.Findings: Over the 24-month study period, seven out of nine DW plants (78%) recorded negative results for all investigated parameters. Closed loop contamination with Burkholderia cepacia was detected in a DW plant from January 2015 to March 2015. Pseudomonas aeruginosa was isolated from March 2016 to May 2016 in the closed loop of another DW plant. These microbial contaminations were eradicated by shock disinfection with sodium hypochlorite and peracetic acid, followed by water flushing.Conclusion: These results highlight the importance of chemical and physical methods of DW disinfection. The maintenance of control measures in water plants hosted in dialysis wards ensures a microbial risk reduction for all dialysis patients. [ABSTRACT FROM AUTHOR]

Introduction: Microbiological culture of dialysis water and fluid is a routine safety measure. In the United States (U.S.), laboratories perform these cultures on trypticase soy agar at 35-37°C for 48 h (TSA-48h), not on the tryptone glucose extract agar or Reasoner's 2A agar at 17-23°C for 7 days (TGEA-7d and R2A-7d, respectively) recommended by international standards. We compared culture methods to identify samples exceeding the accepted action level of 50 CFU/mL. Methods: Dialysis water and fluid samples collected from 41 U.S. dialysis programs between 2011 and 2014 were cultured at two U.S. laboratories. Each sample was cultured using (1) either TGEA-7d or R2A-7d and (2) TSA-48h. We compared proportions exceeding the action level by different methods and test characteristics of TSA-48h to those of TGEA-7d and R2A-7d. Findings: The proportion of water samples yielding colony counts ≥50 CFU/mL by TGEA-7d was significantly different from the proportion by TSA-48h (P = 0.001; difference in proportion 4.3% [95%CI 1.3-7.3%]). The proportions of dialysis fluid samples ≥50 CFU/mL by TGEA-7d and TSA-48h were not significantly different; there were no significant differences for comparisons of R2A-7d to TSA-48h. Discussion: In dialysis fluid, TSA-48h was comparable to TGEA-7d and R2A-7d in identifying samples as having bacterial counts ≥50 CFU/mL. In dialysis water, TSA-48h was comparable to R2A-7d in identifying samples ≥50 CFU/mL, but TGEA-7d did yield significantly more results above 50 CFU/mL. Nonetheless, the negative predictive value of a TSA-48h result of <50 CFU/mL in dialysis water exceeded 95%. [ABSTRACT FROM AUTHOR]

Introduction: The presence of bacteria in the form of biofilms poses a problem in the fluid pathways of haemodialysis plants and procedures which are aimed to detach and neutralize biofilms are necessary to improve the patient safety and the quality of the healthcare. The present study was therefore aimed at isolating the organisms which colonized dialysis water systems as biofilms, as well as to study the effect of the sub inhibitory concentrations of chlorine on the biofilms which were produced by these isolates. Methods: Swabs were used to collect the biofilms which were produced on the internal surface of the dialysis tubing from the dialysis units. This study was conducted at the Department of Microbiology, Kasturba Medical College (KMC), Mangalore, India. The cultures were performed on MacConkey’s agar and blood agar. The organisms which were isolated were identified and antibiotic sensitivity tests were performed. The biofilm production was done by the microtitre plate method of O’Toole and Kolter. The biofilm production was also studied in the presence of sub inhibitory concentrations of chlorine. Results: Acinetobacter spp and Pseudomonas aeruginosa were the two predominant organisms which colonized the dialysis water systems as biofilms. The sub inhibitory concentrations of chlorine did not bring about any decrease in the biofilm production by the isolates. On the contrary, there was an increase in the biofilm production. Conclusion: Our study highlighted the importance of using appropriate methods to improve the quality of the water in dialysis units. This in turn, may help in reducing the biofilm formation in the water systems of dialysis units and thus, contribute to the prevention of hospital acquired infections in the patients who need haemodialysis.

Background: Chemical and microbial quality of water used in hemodialysis play key roles in a number of dialysis-related complications. In order to avoid the complications and to guarantee safety and health of patients therefore, vigorous control of water quality is essential. The objective of present study was to investigate the chemical and bacteriological characteristics of water used in dialysis centers of five hospitals in Isfahan, central Iran. Methods: A total of 30 water samples from the input of dialysis purification system and dialysis water were analyzed for chemical parameters. Heterotrophic plate count and endotoxin concentration of drinking water, dialysis water and dialysis fluid of 40 machines were also monitored over a 5-month period in 2011-2012. Results: Concentration of the determined chemicals (copper, zinc, sulfate, fluoride, chloramines and free chlorine) did not exceed the recommended concentration by the Association for the Advancement of Medical Instrumentation (AAMI) exclude lead, nitrate, aluminum and calcium. Furthermore, the magnesium; cadmium and chromium concentration exceeded the maximum level in some centers. No contamination with heterotrophic bacteria was observed in all samples, while the AMMI standard for endotoxin level in dialysis fluid (

Summary: Background: Fungal contamination of dialysis fluids may be a serious problem in therapy, particularly due to the debilitated immune system of haemodialysis patients. Aim: To investigate the occurrence, distribution, and diversity of fungi in dialysis water and dialysis solution of eight haemodialysis units in a region of central Italy. Methods: Samples were collected over a one-year period from different points of the haemodialysis circuits in accordance with the guidelines of the Italian Society of Nephrology. Isolation and identification of fungi was performed according to the ISTISAN method Reports (2007/05 and 2008/10). Findings: Of the 976 samples analysed, 96 grew filamentous fungi, 28 were positive for yeast, and six samples contained both mould and yeast. A wide variety of filamentous fungi (26 genera, of which 15 identified at species level, and ‘mycelia sterilia’) were recovered, many of which are known as opportunistic pathogens. Cladosporium spp. were most frequently found (39%), followed by Alternaria spp. and Tricophyton spp. Fungal counts in treated water and standard dialysate solution were always below the threshold (<10cfu/mL), and thus are in agreement with the Italian guidelines for dialysis fluid quality, whereas 10.9% of the samples of ultrapure dialysate solution were contaminated by one or several fungi types, in contravention of the guidelines. Conclusion: The large variety of opportunistic fungi recovered in the haemodialysis circuits proves the importance of including an analysis of fungi to check the microbial quality of dialysis water and dialysate. [Copyright &y& Elsevier]

Dialysis water quality is one of the important parameters all over the world because of its direct influence on the health of kidney patients. In Iraq, there are more than 20 dialysis centers; most of them contain identical units for the production of dialysis water. In this work, the quality of water used for dialysis in six dialysis centers located within Baghdad hospitals was evaluated. Samples of product water from each of the six dialysis centers were examined for total heterotrophic bacteria, endotoxin, and chemical contaminants. Endotoxin was measured on-site using a portable instrument. Bacteriological and chemical examinations were done in the laboratory after collecting samples from each dialysis center. The results showed a fluctuation in the produced water quality that makes the produced water unaccepted when compared with international standards. Bacterial counts for 60% of the analyzed samples were above the action level (50 colony-forming units[ CFU]/m L), while five out of the six dialysis centers showed values higher than the maximum value (100 CFU/m L). Chemical analysis showed that the dialysis water quality suffers from elevated aluminum concentration for all dialysis centers. All hemodialysis centers need thorough monitoring and preventive maintenance to ensure good water quality. In addition, it is important to revise the design of the water treatment units according to the feed and product water quality. [ABSTRACT FROM AUTHOR]

Biofilms forming inside dialysis water treatment systems are one of the main sources of microbiological contamination. Among the bacteria found in biofilms, Ralstonia pickettii is frequently encountered in dialysis water treatment systems and has been shown to develop extreme oligotrophic talents. In Austria, R. pickettii was exclusively detected in high numbers in dialysis water treatment facilities equipped with chlorinated polyvinyl chloride (PVC-C) piping. In this laboratory study it was shown that PVC-C effectively promotes growth of R. pickettii biofilms, while residual organic carbon in purified dialysis water is sufficient for promoting substantial growth of planktic R. pickettii. This provides evidence that PVC-C is an unsuitable material for piping in dialysis water treatment systems. [ABSTRACT FROM AUTHOR]

Introduction: The presence of bacteria in the form of biofilms poses a problem in the fluid pathways of haemodialysis plants and procedures which are aimed to detach and neutralize biofilms are necessary to improve the patient safety and the quality of the healthcare. The present study was therefore aimed at isolating the organisms which colonized dialysis water systems as biofilms, as well as to study the effect of the sub inhibitory concentrations of chlorine on the biofilms which were produced by these isolates. Methods: Swabs were used to collect the biofilms which were produced on the internal surface of the dialysis tubing from the dialysis units. This study was conducted at the Department of Microbiology, Kasturba Medical College (KMC), Mangalore, India. The cultures were performed on MacConkey's agar and blood agar. The organisms which were isolated were identified and antibiotic sensitivity tests were performed. The biofilm production was done by the microtitre plate method of O'Toole and Kolter. The biofilm production was also studied in the presence of sub inhibitory concentrations of chlorine. Results: Acinetobacter spp and Pseudomonas aeruginosa were the two predominant organisms which colonized the dialysis water systems as biofilms. The sub inhibitory concentrations of chlorine did not bring about any decrease in the biofilm production by the isolates. On the contrary, there was an increase in the biofilm production. Conclusion: Our study highlighted the importance of using appropriate methods to improve the quality of the water in dialysis units. This in turn, may help in reducing the biofilm formation in the water systems of dialysis units and thus, contribute to the prevention of hospital acquired infections in the patients who need haemodialysis. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to evaluate the microbial contamination and bacterial endotoxin levels in dialysis water samples sent to the Water and Food Microbiology Laboratory of the Adana Hygiene Institute Refik Saydam Hygiene Center, and to assess factors that might influence the results of these tests. Method: Two hundred fourty five dialysis water samples sent to the laboratory between January 2009 and December 2010 were tested; all of them for microbial contamination and 198 of them for bacterial endotoxin levels. Microbial contamination was evaluated by using the Plate Count Agar (PCA) method while the Limulus Amoebocyte Lysate (LAL) assay was used for the detection of bacterial endotoxins. The results were evaluated according to the criteria of the "Directives on the Water Purification Systems" and "the European Pharmacopoeia". To compare the annual differences, the chi-square test was used for statistical evaluation and results with p<0.05 were considered statistically significant. Results: Total aerobic microorganism count (TAMC) found by microbial contamination test higher than 100 CFU/ml were 11.7% in 2009, while only 4.8% (p>0.05) in 2010. On the other hand, in 26.7% of the dialysis water samples the levels of bacterial endotoxins was higher than 0.25 İU/ml in 2009, this percentage dropped to 16.5% in 2010 (p>0.05). During 2009-2010, 245 microbial contamination tests were performed and in 20 (8.2%) of the samples the TAMC values were higher than 100 CFU/ml, while in 43 (21.7%) out of 198 of the samples the bacterial endotoxin levels were higher than 0.25 İU/ml. Out of 20 in 43 samples, a bacterial endotoxin levels were >0.25 İU/ml were also found as microbiologically contaminated ( >100 CFU/ml), while in remaining 23 samples the level was <100 CFU/ml. There were no statistically significant differences in the percentages of positives found in 2009 and 2010. Conclusion: The results of our study indicate that the detection of endotoxins is a complementary factor to microbial contamination in the bacteriological monitoring of dialysis waters. We recommend that level of endotoxin should be taken into account when the bacterial contamination test is used. It is important that periodic control of dialysis waters should be done by different reliable laboratory tests. [ABSTRACT FROM AUTHOR]

L'HDF est actuellement pratiqué chez 35 % des patients dialysés chroniques en France d'après le registre REIN. Son surcoût par séance a été évalué à 1 euro par séance et le surcoût en QALYS dépend essentiellement de l'augmentation de survie liée à la technique. Sur un plan réglementaire, l'eau de dialyse n'est ni un médicament ni un dispositif médical, mais intervient de façon majeure dans la prise en charge thérapeutique du patient dialysé. Les contrôles et les limites acceptables de l'eau à usage médical et des dialysats produits pour les techniques d'hémodialyse conventionnelle ou l'hémodiafiltration en ligne sont décrits dans diverses recommandations nationales et internationales applicables en France. Les circulaires Françaises de 2000 et de 2007 relatives à la technique HDFL sont parfois en contradiction ou en incohérence avec les recommandations AFNOR internationales applicables depuis 2019 en France particulièrement en termes d'exigences microbiologiques sur les dialysats ultrafiltrés. La norme ISO 23500 indique qu'il n'est pas nécessaire de réaliser des essais de la croissance bactérienne et des endotoxines sur le dialysat si le système de production est équipé d'un filtre de rétention d'endotoxines validé par le fabricant, et utilisé et surveillé conformément aux instructions du fabricant. Ainsi, selon la norme internationale, les établissements pourraient supprimer les contrôles microbiologiques sur le dialysat une ou deux fois ultrafiltré ; ces derniers sont incités à déterminer leur politique de surveillance à partir d'une analyse de risque de leur filière de fabrication de l'eau pour dilution des solutions concentrées de dialyse et des différents dialysats. Les différents intervenants et leurs interfaces dans la gestion du risque associé à la production d'un liquide de qualité injectable doivent être pris en compte : le fournisseur d'eau potable, les fabricants des dispositifs de la filière et l'équipe pluridisciplinaire de l'établissement de santé. La révision nécessaire des circulaires Françaises doit s'appuyer sur la Norme ISO 23500 correspondant à l'état de l'art, et si besoin être complétée des préconisations spécifiquement françaises telle que l'exigence de la double osmose ou un système équivalent dans la filière de fabrication du dialysat en HDFL. Autoriser la technique d'HDFL en autodialyse si l'analyse des risques de la filière de fabrication du dialysat est favorable, permettrait aux patients pris en charge dans ces structures de bénéficier de cette technique. HDF is used by 35% of the hemodialysis patients in France, according to the REIN registry. The extra cost per session was evaluated at 1 euro per session and the extra cost in QALYS mainly depends on the survival increase imputed to HDF. From a regulatory standpoint, dialysis water is neither a medicinal product nor a medical device, but plays a major role in the treatment of dialysis patients. The controls and acceptable limits for water and dialysis fluid produced for conventional high-flux hemodialysis and on-line hemodiafiltration are described in various national and international guidelines applicable in France. The French circulars of 2000 and 2007 relating to the OL-HDF technique are sometimes in contradiction or inconsistent with the international AFNOR recommendations applicable in France since 2019, particularly in terms of microbiological requirements for ultrafiltered dialysates. The ISO 23500 standard indicates that it is not necessary to test dialysis fluid for bacterial growth and endotoxins when the production system is equipped with an endotoxin retention filter validated by the manufacturer, and used and monitored according to the manufacturer's instructions. Thus, according to the international standard, dialysis care facilities could disregard microbiological controls on dialysates that have been ultrafiltered once or twice; care facilities are encouraged to determine their monitoring policy based on a risk analysis of their process for producing water for the dilution of concentrated dialysis solutions and various dialysis fluids. The various stakeholders and their interfaces in the management of the risks associated with the supply of injectable quality liquids must be taken into account: the drinking water supplier, the device manufacturers of the sector and the multidisciplinary team of the health institutions. The essential revision of the French circulars must be based on the ISO 23500 Standard which corresponds to the state of the art, and if necessary be accompanied by specifically French recommendations such as the requirement to use a double pass reverse osmosis or equivalent system in the OL-HDF dialysate production process. Authorizing the OL-HDF technique for self-care dialysis units including home treatment, if the risk analysis of the dialysate production process is favorable would allow patients treated in these institutions to benefit from this technique. [ABSTRACT FROM AUTHOR]

Objective: To compare the detection ratio of bacterial colony count in dialysis water, dialysate and raw water with different media and different incubation conditions, searching for suitable methods to detect bacteria from dialysis water. Methods: Between Jan 2012 and Dec 2012, 176 samples of hemodialysis water and dialysate, 88 samples of raw water were collected by hemodialysis unit, Renji hospital. Samples were inoculated in duplicate on spread plates with Blood agar, Reasoner's 2A (R2A), Tryptone glucose extract agar (TGEA) respectively, at different temperature and time. After incubation, the numbers of colonies were quantified. Results: The bacterial colony counts in dialysis water, dialysate and raw water were the lowest in blood agar and the difference had statistical significance when it was compared with that of R2A or TGEA culture media (P < 0.01). The detection rate of dialysis water and dialysate were 61.9% in R2A at 20°C for 168 hours. According to the standard of the association for the advancement of medical instrumentation (AAMI), the detection rate had no difference among these media with different conditions. Combined with medium of R2A and TGEA, the detection rate of bacteria was 77.6% at 20°C for 168 hours and the bacteria detection rate was significantly increased than that in culture R2A or TGEA respectively under the same conditions (77.6% vs. 61.9%, 50.6%, P value was 0.003 and 0.001). Conclusions: The method of R2A or TGEA agar culture can improve the detection rate of bacterial colony count compared with the method of blood agar. The method of R2A combined with TGEA at 20°C for 168 hours can improve the detection rate of bacteria in dialysis water and dialysate. [ABSTRACT FROM AUTHOR]

Culture-dependent methods, such as heterotrophic plate counting (HPC), are usually applied to evaluate the bacteriological quality of hemodialysis water. However, these methods cannot detect the uncultured or viable but non-culturable (VBNC) bacteria, both of which may be quantitatively predominant throughout the hemodialysis water treatment system. Therefore, propidium monoazide (PMA)-qPCR associated with HPC was used together to profile the distribution of the total viable bacteria in such a system. Moreover, high-throughput sequencing of 16S rRNA gene amplicons was utilized to analyze the microbial community structure and diversity. The HPC results indicated that the total bacterial counts conformed to the standards, yet the bacteria amounts were abruptly enhanced after carbon filter treatment. Nevertheless, the bacterial counts detected by PMA-qPCR, with the highest levels of 2.14 × 10 7 copies/100 ml in softener water, were much higher than the corresponding HPC results, which demonstrated the occurrence of numerous uncultured or VBNC bacteria among the entire system before reverse osmosis (RO). In addition, the microbial community structure was very different and the diversity was enhanced after the carbon filter. Although the diversity was minimized after RO treatment, pathogens such as Escherichia could still be detected in the RO effluent. In general, both the amounts of bacteria and the complexity of microbial community in the hemodialysis water treatment system revealed by molecular approaches were much higher than by traditional method. These results suggested the higher health risk potential for hemodialysis patients from the up-to-standard water. The treatment process could also be optimized, based on the results of this study.