Abstract:

Abstract Introduction: The microbiological quality of hemodialysis treated water is directly related to the occurrence of infections and pyrogenic reactions in patients. Objective: Determine the minimum incubation time and evaluate the alternative microbiological method performance for heterotrophic bacteria count in hemodialysis water through the fluorescence microbial detection technique. Method: The analyses were conducted by concentration levels of 2,5 x 10-1 to 1,0 x 102 CFU/plate for Pseudomonas aeruginosa, Burkholderia cepacia, Escherichia coli and Staphylococcus aureus. The tests were performed simultaneously by the alternative and the traditional methods, using culture medium R2A and incubation temperature of 24.0°C ± 4.0°C. The incubation times were 40 h and 120 h, respectively. Fourteen hemodialysis water samples were analyzed to assess the equivalence between the methods evaluated. Results: The results demonstrated that the alternative method allows quantification of heterotrophic bacteria after 40 h of incubation, with accuracy, precision, specificity and linearity for the range of 5 to 100 CFU/plate. The detection limit of the alternative method is 1 CFU/plate. Conclusions: It was possible to conclude that the alternative method has equivalent results to the traditional method, since the confidence interval of the alternative method was entirely within the equivalence range. Therefore, the microbial detection technique by fluorescence showed a viable option for the implementation of a rapid microbiological method for the heterotrophic bacteria count in samples of treated water for hemodialysis.

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