Method for Assay of Antimicrobial Activity of Fabrics

Modification of JIS L1902 halo-test for assay of antibacterial activity of textiles treated with antimicrobial and deodorant reagents was attempted to increase the sensitivity and efficiency. The results were as follows : 1. There was no difference in the width of zone of inhibition (ZI) between 28 and 20 mm diameter patches used in the test. 2. A wider clear zone was observed with a inoculum (10^3 cfu/ml) than with a large inoculum (10^6 cfu/ml), showing that the reduction of inoculum size increases the sensitivity. These results suggest that tha usage of a small inoculum could be very useful for the estimation of antimicrobial activity of fabrics treated with dyes having weak antimicrobial activity, such as plant dyes. 3. No difference was seen in the width of ZI between a smear method and a pour-plating method, although the ZI by a pour-plating method was more clearly outlined. The operation of a smear method is easier