Table 1.

Testing matrix.

Challenge microorganism	Biofilm growth medium (BGM)	Model	Test methodology	Dressings tested (Table 2)
Antibiotic-resistant Pseudomonas aeruginosa NCTC 13437   Community-acquired Methicillin-resistant Staphylococcus aureus (CA-MRSA) USA300   Candida albicans NCPF 3179	Foetal calf serum (FCS)	Simple biofilm model	Elemental analysis (K+, Mg2+, Ca2+, Zn2+, Ag+) of residual biofilm after dressing being applied for 24 hours (a simple and chemically consistent model to investigate formulation effects) (n = 6)	CMC SCMC NGAD
Antibiotic-resistant P. aeruginosa NCTC 8506			Elemental analysis (Ag+) and quantitative live/dead staining after dressing being applied for 48 hours (a more challenging strain and longer dressing exposure time selected to challenge the silver-containing dressings) (n = 9)	NGAD NCSD SNAD
S. aureus (clinical wound isolate, CI72) and Klebsiella pneumoniae (clinical isolate, CI45)	TSB : FCS (50 : 50)	Simulated wound polymicrobial biofilm model	Quantitative microbiology (total viable counts), PNA FISH, live/dead and Calcofluor White staining after dressing application for 48 hours (a more complex inoculum and longer dressing exposure time selected to challenge the silver dressings) (n = 5)	NGAD NCSD SNAD