AATCC 147-2016e:2019 pdf download.Test Method for Antibacterial Activity of Textile Materials: Parallel Streak
1. Purpose and Scope
1.1 The objective is to detect bacteriostatic activity on textile materials. The resuits of using this procedure have been demonstrated by Committee RA31 to be reproducible by various laboratones working with materials containing residual amounts of antibacterial agents (as determined by chemical assay) after multiple standard washings. The method is useful for obtaining a rough estimate of activity in that the growth of the inoculum organism decreases from one end of each streak to the other and from one streak to the next resulting in increasing degrees of sensitivity. The size of the zone of inhibition and the narrowing of the streaks caused by the presence of the antibacterial agent permit an estimate of the residual antibacterial activity after multiple washings.
2. Principle
2.1 Specimens of the test material, in- ci udi ng corresponding untreated controls of the same material, are placed in intimate contact with the agar surface which has been previously streaked with an inocuium of a test bacterium. After incubation, a clear area of interrupted growth underneath and along the sides of the test material indicates antibacterial activity of the specimen. A standard strain of bacteria is used which is specific to the requirements of the material under test. If no other bacterial species is specified, Staph vlococcu.c aureus may be used as a representative Gram posin ye organism. Other recommended strains are listed beloW in Section 6.
10.2 The size of the zonc cannot be construed as a quantitative evaluation of antibacterial activity. Treated materials should be compared to all untreated corresponding material and a material specimen with known bactcriostatic activity. Report of results will include an observation of zones of inhibition and growth under the specimen if present. The criterion for passing the test must be agreed upon by the interested parties. To constitute acceptable antibacterial activity, there must be no bacterial colonies directly under the sample in the contact area.AATCC 147-2016e pdf download.