SP410EFFECT OF BIOFILM FORMATION ON HEMODIALYSIS MONITOR DISINFECTION
Bibliographic record
Abstract
Introduction and Aims: Biofilms are composed of communities of microorganisms that adhere to almost any surface. In correct conditions of a hemodialysis apparatus, the probability of biofilm formation within its hydraulic circuit is very low. In particular situations, e.g. long periods of downtime or use of water with a high bacterial content, this probability increases considerably. The aim of this work was to evaluate the combined effect of two different disinfection methods: physical (descaling with citric acid at 70°C) and chemical (disinfection with Oxagal®), on reduction of bacteria contents in a hemodialysis monitor (FLEXYA® Dialysis Machine). In particular, the effectiveness of the disinfection action despite the biofilm presence inside the hydraulic circuit was investigated. Methods: The hydraulic circuit of FLEXYA was intentionally contaminated according two different contamination protocols, A and B described below, using a 108 CFU/ml suspension of Pseudomonas aeruginosa. For the bacteria determination, sample of water volume was aspirated at 0, 24, 48 and 72 h after disinfection from different sampling sites of the hydraulic circuit: on dialysate outlet (before entry in the hemodialyser), immediately after heating tank, after mixing and after the recirculation circuit. Samples were filtered through a 0.45 μm membrane filter. The filter was placed in culture at 32°C for 5 days on Reasoner 2A agar plates. Protocol A: The monitor was contaminated by recirculating 500 ml of the bacterial suspension for 1 hour at 37°C. The hydraulic circuit, washed with deionized water for 5 min at 500 ml/min, was disinfected with the two different procedures: physical followed by a chemical disinfection with 60 hour of stationing. The monitor was finally, turned off and samples were taken at 0, 24, 48 and 72 h of non-use. Protocol B: The monitor was contaminated by recirculating 500 ml of the bacterial suspension for 1 h at 37°C, then switched off leaving the bacterial suspension inside the circuit for 72 h in order to allow biofilm formation. The monitor was washed with deionized water for 5 min at 500 ml/min and later, was disinfected with a physical followed by a chemical disinfection with different time of stationary phase: 60, 36, 24 and 12 hours. For each stationary phase duration, samples were taken at 0, 24, 48 and 72 h of non-use.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".