Evaluation of Durability to Laundering of Triclosan and Chitosan on a Textile Substrate

In a hospital environment, textile substrates have been implicated as a vector in the transmission of disease. To mitigate the harmful spread of disease via textile substrates, an effective measure is treatment of textiles with antimicrobial agents. The current investigation compares one of the most widely used chemically synthesized antimicrobial agents, triclosan with chitosan, a naturally occurring antimicrobial agent. For the study, samples of a common polyester/cotton textile used in hospital settings were treated with triclosan and chitosan based antimicrobial agents. Following treatment, the samples were analyzed for their effectiveness against Staphylococcus aureus and Escherichia coli using standard AATCC Test Methods. The efficacy of the treatment to laundering was then evaluated by subjecting the treated samples to 50 washings and repeating the tests against the challenge microorganisms. Data obtained were statistically analyzed at a 95% confidence interval. Results showed that before laundering both triclosan and chitosan treated samples were extremely effective as antimicrobial agents. After laundering, chitosan was less effective against E.coli but maintained efficacy against S. aureus. The effectiveness of triclosan was not adversely affected after the laundering treatments. 1. Introduction The Centers for Disease Control and Prevention, USA, estimate that approximately 1.7 million healthcare associated infections (HAIs) and 98,987 associated deaths occur each year on account of infection-causing bacteria. Hence, the control of infections has been identified as the most important target by the United States Department of Health and Human Services [1]. Textile substrates have been implicated as one of the vectors of transmission of infections. Fortuitously, the use of antimicrobial textiles is an effective deterrent against the spread of infection-causing bacteria [2]. Triclosan, a chlorinated phenolic compound, is a derivative of a diphenyl ether compound. Triclosan is most widely used in various medical and consumer care products. Triclosan belongs to leaching or controlled release category of antimicrobial agents [2, 3]. The mechanism of action of triclosan on a textile substrate is illustrated in Figure 1. The figure depicts a treated fiber containing a reservoir of antimicrobial agent. When the chemical agent ions are released outside the fiber they destroy microbes present in the vicinity. Triclosan inhibits the growth of microbes by using an electrochemical mode of action to penetrate and disrupt the cell wall of microbes [2, 4]. It