AATCC TM 147 – Antibacterial Activity Assessment of Textile Materials: Parallel Streak Method

Purpose and Goals

• Evaluate and compare the antimicrobial activity of multiple textiles in laboratory-controlled testing. 

Testing

• Textile specimens (25 x 50 mm) will be placed across 5 fresh parallel streaks of bacteria/fungus on a nutrient agar plate. A sterile glass slide may be pressed atop the specimen to ensure complete contact with the lines of bacteria/fungus. Each agar plate will then be incubated at the test organism’s ideal growth temperature (37°C) for 24 hours of continuous contact. At the end of the contact time, without moving the test specimens, the plates will be checked for bacterial/fungal growth. Any clear zones of inhibition (where the parallel streaks have been interrupted) beyond the edge of the textile specimen will be measured to provide qualitative bacteriostatic data about the efficacy of any diffusable antimicrobial agents in each material.
• Each test will include one of the microbial strains:
  • Staphylococcus aureus​ ATCC 6538 (a standard test strain) bacteria
  • Methicillin-resistant ​Staphylococcus aureus​ ATCC 33592 (MRSA) bacteria
  • Klebsiella pneumoniae ATCC 4352 (a standard test strain) bacteria
  • Carbapenem-resistant Klebsiella pneumoniae ATCC BAA-1705 (KPC, CRE) bacteria
  • Candida auris CDC B11903 fungus 
  • Staphylococcus epidermidis ATCC 35984 bacteria
  • Salmonella enterica ATCC 10708 (formerly known as ​S. choleraesuis​) bacteria
  • Salmonella enterica​ ATCC 14028 (formerly known as ​S. typhimurium​) bacteria
  • Shigella flexneri ATCC 12022 bacteria
  • Escherichia coli ATCC 25922 (a standard test strain) bacteria
  • Escherichia coli ATCC 43888 (an O157:H7 strain) bacteria
  • Listeria monocytogenes ATCC 7644 bacteria
  • Pseudomonas aeruginosa ATCC 9027 or 15442 bacteria
  • Alternate microbial strains are available upon request for a New Strain Fee.
• Testing will include 24 total data points per microbial strain:
  • 2 total materials (1 test textile and 1 in-house negative control)
    • Note: Please provide at least 10 grams of each material per time-point. 
  • 1 contact time-point (24 hours)
  • 3 replicates per material at each test condition
  • 2 independent tests
• Note: Optional GLP services are available for an additional 25% fee.
• Note: Bulk discounts are available for 4+ materials.

Data Analysis

• In-house control results will be used to verify test validity. 
• Data will be calculated to determine the width of the zone of inhibition for each material.
• Data will be analyzed to determine the consistency between replicate materials in each set (n=6).

Link: https://members.aatcc.org/store/tm147/554/