| Title | Sterilization efficiency of pathogen-contaminated cottons in a laundry machine |
|---|---|
| Author | Yoonjae Shin1, Jungha Park2, and Woojun Park1* |
| Address | 1Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul 02841, Republic of Korea, 2Digital Appliances Business, Samsung Electronics, Suwon 16677, Republic of Korea |
| Bibliography | Journal of Microbiology, 58(1),30–38, 2020, |
| DOI | 10.1007/s12275-020-9391-1 |
| Key Words | Acinetobacter baumannii, desiccation tolerance, dry conditions, drying machine, Staphylococcus aureus, washing machine |
| Abstract | Pathogenic bacteria on abiotic surfaces such as fabrics, bedding, patient wears, and surgical tools are known to increase the risk of bacterial diseases in infants and the elderly. The desiccation tolerance of bacteria affects their viability in cotton. Thus, washing and drying machines are required to use conditions that ensure the sterilization of bacteria in cotton. The objective of this study is to determine the effects of various sterilization conditions of washing and drying machines on the survival of three pathogenic bacteria (Acinetobacter baumannii, Pseudomonas aeruginosa, and Staphylococcus aureus) commonly presented in contaminated cotton and two non-pathogenic bacteria (Bacillus subtilis and Escherichia coli) in cotton. High survival rates of A. baumannii and S. aureus in desiccated cotton were observed based on scanning electron microscope and replicate organism direct agar contact assay. The survival rates of A. baumannii and S. aureus exposed in desiccated cotton for 8 h were higher (14.4 and 5.0%, respectively) than those of other bacteria (< 0.5%). All tested bacteria were eradicated at low-temperature (< 40°C) washing with activated oxygen bleach (AOB). However, bacterial viability was shown in low temperature washing without AOB. High-temperature (> 60°C) washing was required to achieve 99.9% of the sterilization rate in washing without AOB. The sterilization rate was 93.2% using a drying machine at 60°C for 4 h. This level of sterilization was insufficient in terms of time and energy efficiency. High sterilization efficiency (> 99.9%) at 75°C for 3 h using a drying machine was confirmed. This study suggests standard conditions of drying machines to remove bacterial contamination in cotton by providing practical data. |