抄録
Dishwashers are one of the sources of bacterial contamination in dishes despite the fact that
they comprise extreme environments due to the high temperature, high pH, and the presence of
detergents during their operation. In this study, viable bacteria were isolated from 6 door-type and 8
conveyor-type dishwashers that were being used in food service facilities. Each door- and conveyortype
dishwasher was divided into 6 and 9 sections respectively. Thermophilic bacteria, which grow at
60˚C, were obtained from 5 sections of door-type dishwashers, but obtained from one section of
conveyor-type dishwashers tested. The 16S rRNA sequences of the cultured isolates revealed that fewer
Gram-negative bacterial strains were found in door-type dishwashers than in conveyor-type
dishwashers. The most frequently identified bacterial species in the samples tested were spore-forming
bacteria, such as Bacillus and Anoxybacillus species. This study highlights the vulnerabilities presented
by dishwashers used in food service facilities.
