AATCC 174

AATCC 174 covers the following three antimicrobial test procedures –

1) AATCC 174 Test I  – Qualitative Antibacterial Assessment, Single Streak Method

• Molten agar medium is poured onto sterile petri plates and allowed to solidify. Staphylococcus aureus (ATCC 6538P) and Klebsiella pneumoniae (ATCC 4352) are mandatory test microorganisms in AATCC 174 Test I and AATCC 174 Test II.
• Using a sterile inoculating loop, test microorganisms are streaked over the surface of agar medium.
• Both treated (test ) and untreated (control) carpet samples are placed transversely across inoculated streaks.
• After 24 hours of incubation, plates are examined for zones of inhibition.

2)  AATCC 174 Test II – Quantitative Assessment of Antibacterial Activity on Carpets

• Bacterial inoculum is spread onto pre-wetted treated (test) and untreated (control) carpet samples. 
• Immediately after inoculation (0 contact times), bacterial enumeration is done for control samples followed by neutralization, plating, and incubation. 
• Other test samples are incubated for 24 hours. 
• After incubation, neutralizing solution is added to test samples to extract remaining bacteria. And plate count method is used to enumerate the number of viable bacteria present in sample.
• Reduction in the number of viable bacteria in test sample is compared with bacterial count recovered at 0 contact times.

3) AATCC 174 Test  III – Qualitative  Antifungal Assessment (Mildew and Rot Resistance of Carpet Materials)

• Aspergillus niger (ATCC-16888) is test microorganism in AATCC 174 Test  III.
• Both treated and untreated carpet samples are placed on agar surface which is inoculated with test microorganisms.
• Plates are kept for 7 days incubation period and examined for fungal growth.