Determining the time required to disinfect a sponge contaminated with Escherichia coli, using a commercial microwave
Bassan, Amrita (author)
Sidhu, Bobby (Advisor)
Keilbart, Ken (Advisor)
Shaw, Fred (Advisor)
British Columbia Institute of Technology School of Health Sciences (Degree granting institution)
Background: Disinfection and sanitation are important in areas where food is involved. Thorough cleaning is a necessity to prevent growth of harmful pathogens that could affect human health. Sponges used for cleaning can serve as a vehicle for cross-contamination on food preparation surfaces. There are various methods that could be used to disinfect contaminated sponges. The usage of a microwave is one suggested method. Objective: The purpose of this study was to determine if the Scotch-BriteTM Brand, cellulose sponges contaminated with E.coli (105 cfu/ml) could be disinfected using a microwave set at three timings (30 seconds, 1 minute, and 2 minutes). Methods: The Hygiena MicroSnap was used to detect the presence (or absence) of E.coli in sponges after microwave heating. The relative light units (RLU) indicated in the monitor determined whether there were any remaining coliforms in the sample after microwaving. Results: Statistical analysis was conducted using Microsoft Excel and NCSS. After heating sponges for 30 seconds, 100% of the samples detected no E.coli. After heating for 1 minute, 70% of the samples had no E.coli present. After heating for 2 minutes, 100% of the samples detected no E.coli. The p-value of 0.03567 concludes that the results were statistically significant at the 5% significance level. Discussion: The results of this study indicate that sponges contaminated with E.coli can be disinfected using microwave heating. EHOs, food establishment operators, and the general public can use this knowledge to re-use their old sponges and avoid further cross-contamination. Conclusions: The results indicate that microwave time is associated with the presence or absence of E.coli in a sponge. However, E.coli was present in 3 samples microwaved at 1 minute. This suggests further studies are required to confirm the findings of this study. In addition, further studies are required to determine what specific time is sufficient to completely eliminate the E.coli in a contaminated sponge.
© Amrita Bassan, 2014. All rights reserved. No part of this work covered by the copyright heron may be reproduced or used in any form or by any means – graphics, electronic, or mechanical including photocopying, taping, or information storage and retrieval systems – without written permission of the author.
Project submitted in partial fulfillment of the requirement for the degree of Bachelor of Technology in Environmental Health, British Columbia Institute of Technology, 2014.