Time survivor study of Escherichia coli with polyhexamethylene biguanide on cotton

Time survivor or time kill studies are commonly used to investigate the efficacy of antimicrobial agents in homogeneous solutions. Such a study was attempted via a textile treated with an antimicrobial agent. For this study, a finished undyed cotton fabric and a commercially available antimicrobial agent, polyhexamethylene biguanide, were used. The release of the antimicrobial agent from the cotton fabric when submerged in water with a liquor-to-cloth ratio of 20:1 was evaluated. The antibacterial agent-treated cotton fabric was also tested according to the JIS L 1902 absorption antibacterial testing method at various agent concentrations applied to the fabric and incubation times. The treated textile showed a quick release of agent when submerged in water and the results of the antibacterial tests showed increasing antibacterial activity with increases in concentration, as has been found in homogeneous solutions. Fabrics treated with lower concentrations of the agent show bacteriostatic action. A regrowth of microorganisms was additionally noted at certain incubation times.