Survival and growth of Escherichia coli on various commercial dish sponge/dishcloths and inhibitory effect of UV sterilization with or without moderate heat
2010
Lee, Sun Young
This study investigated the survival and growth of Escherichia coli ATCC 25922 on various dish sponges/dishcloths, and the effect of ultraviolet (UV) and heat (50C) in killing E. coli on the dish sponges/dishcloths. Pulp material itself can inhibit E. coli; therefore, levels of E. coli on pulp sponge samples were under the detection limit (0.3 log₁₀ cfu/each) after 3 h of storage. However, levels of E. coli on rayon, cotton and polyester significantly increased with storage and resulted in high populations (>8 log₁₀ cfu/each) after 24 h of storage. When the samples were treated with UV, heat or the combination of UV and heat, the treatment with heat alone was not effective at reducing levels of E. coli, whereas the treatments of UV or UV combined with heat significantly reduced E. coli levels on rayon and cotton. The reduction levels on cotton by treatment with UV, heat and their combination were 2.2, 1.1 and 3.0 log₁₀ cfu/each, respectively. Dish sponge/dishcloths can act as sources of pathogenic bacteria through cross-contamination to foods. The results of this study indicate that microbial cells contained on commercial sponges/cloths grow quickly depending on the materials that they are made from. Therefore, proper sanitizing methods must be applied to prevent the cross-contamination of pathogenic bacteria by dish sponges/dishcloths in domestic and foodservice kitchens. Also, this study showed the effectiveness of ultraviolet sterilization and moderate heat for sanitizing dish sponges/dishcloths contaminated with Escherichia coli. Therefore, this report provides evidence of the necessity for sanitizing dish sponges and dishcloths as well as helpful information for ways in which those materials can be sanitized.
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