Rapid count of microbial cells in dialysate

Area of Science:

• Microbiology
• Biotechnology
• Medical Diagnostics

Background:

• Microbial contamination in dialysis fluid poses a significant health risk.
• Conventional culture methods (CM) for microbial detection are time-consuming.
• Rapid and accurate methods for monitoring dialysate quality are essential.

Purpose of the Study:

• To evaluate the bioplorer non-culture method (NCM) for microbial cell counting in dialysate.
• To compare the NCM with conventional culture methods for accuracy and speed.
• To assess the NCM's ability to detect microbial contamination in hospital dialysis facilities.

Main Methods:

• The bioplorer NCM utilizes dual staining with DAPI and PI, followed by automated fluorescent microscopic image analysis.
• Viable cells stain with DAPI; dead cells stain with both DAPI and PI.
• Samples from a hospital dialysis facility were analyzed using both NCM and CM.

Main Results:

• The bioplorer NCM quantified viable and dead cells in dialysate within 20 minutes, with a detection limit of 2.0 log(10)[cells/100 mL].
• NCM results closely correlated with conventional culture methods for spiked samples (2.6-4.6 log(10)[cells/100 mL]).
• Analysis of hospital samples showed comparable, though slightly higher, microbial counts with NCM compared to CM.

Conclusions:

• The bioplorer NCM provides a rapid and reliable method for assessing microbial contamination in dialysate.
• The method can effectively determine microbial contamination levels exceeding 2.6 log(10)[cells/100 mL] (398 cells/100 mL).
• The study confirmed the cleanliness of the tested dialysate supply line, demonstrating the NCM's utility in quality control.