Microbial Contamination of Ice Machines Is Mediated by Activated Charcoal Filtration Systems in a City Hospital


Although microbial contamination of ice machines has been reported, no previous study has addressed microbial contamination of ice produced by machines equipped with activated charcoal (AC) filters in hospitals. The aim of this study was to provide clinical data for evaluating AC filters to prevent microbial contamination of ice. We compared microbial contamination in ice samples produced by machines with (n = 20) and without an AC filter (n = 40) in Shunan City Shinnanyo Municipal Hospital. All samples from the ice machine equipped with an AC filter contained 10–116 CFUs/g of glucose non-fermenting gram-negative bacteria such as Pseudomonas aeruginosa and Chryseobacterium meningosepticum. No microorganisms were detected in samples from ice machines without AC filters. After the AC filter was removed from the ice machine that tested positive for Gram-negative bacteria, the ice was re-sampled (n = 20). Analysis found no contaminants. Ice machines equipped with AC filters pose a serious risk factor for ice contamination. New filter-use guidelines and regulations on bacterial detection limits to prevent contamination of ice in healthcare facilities are necessary.

Speaker / Author: 
Katsuhiro Yorioka, PhD
Shigeharu Oie, PhD
Koji Hayashi
Hiroo Kimoto
Hiroyuki Furukawa, PhD
Month Year: 
June 2016
Page #: 
Publication Month: 
June 2016
EH Topics: