Table 4.
In vitro protocols used for testing the activity of new dressings
| Antimicrobial | Protocol | Bacterial target | Reference |
|---|---|---|---|
| Chlorhexidine | |||
| chlorhexidine | ASTM E2647-13 | A. baumannii, Enterobacter aerogenes, E. faecalis, E. coli, K. pneumoniae, P. aeruginosa, S. marcescens, S. aureus | 204 |
| Non-standard test | 190 | ||
| CLSI disc diffusion | S. aureus | 204 | |
| CLSI disc diffusion | E. coli (ATCC 25922), A. baumannii (ATCC 19606), P. aeruginosa (ATCC 27853), B. subtilis (ATCC 6633), S. aureus (ATCC 25923), and S. aureus (MRSA) | 190 | |
| Non-standard. Immersing dressing in solution, adding bacterial inoculum for 16 h at 37°C, removing dressing and recovering bacteria from the dressing |
S. aureus (EMRSA-15 and MSSA), P. aeruginosa (ATCC9027 and PA14), K. pneumoniae (ATCC10031), A. baumannii (121J6), E. coli (NCTC10418) and S. epidermidis, C. difficile |
198 | |
| CHG-containing dressing | Zone of inhibition on seeded agar + dressing in broth for up to 24 h at 35°C | S. aureus, B. subtilis, E. coli, P. aeruginosa. | 191 |
| Iodine | |||
| cadexomer iodine | Porcine ex vivo | P. aeruginosa (biofilm) | 207 |
| cadexomer iodine dressing | Shake flask assay: inoculum in the presence of dressing for 1–6 h at 37°C + use of neutralizer | P. aeruginosa ATCC 27312 and ATCC 15442, S. aureus ATCC 6538 | 199 |
| cadexomer iodine | Porcine ex vivo | P. aeruginosa (biofilm) | 207 |
| Silver | |||
| silver sulfadiazine | S. aureus, P. aeruginosa | 205 | |
| silver sulfadiazine 1% | Non-standard ex vivo test on human skin | P. aeruginosa | 208 |
| silver sulfadiazine/ silver nitrate | Zone of inhibition on seeded agar | S. aureus | 192 |
| AgNPs | Zone of inhibition on seeded agar | S. aureus ATCC25923 | 211 |
| silver-based dressings | Bacteria inoculated on hydrogels and recovered after 1 h at 37°C with 90% relative humidity | E. coli 8379, S. aureus 29213, K. pneumoniae 13883, A. baumannii 19606, MRSA USA300, P. aeruginosa PAO1 + carbapenem-resistant, P. aeruginosa, carbapenem-resistant A. baumannii | 218 |
| nano-composite alginate gel discs containing AgNPs | Coated discs in inoculate broth for 24 h at 37°C | S. aureus (ATCC 6538) and MRSA (ATCC 43300), A. baumannii (ATCC 19606) + 13 carbapenem- resistant strains, E. coli (ATCC 10536) and P. aeruginosa (ATCC 9027) + 1 wound isolate | 200 |
| 200 ppm AgNPs | CLSI disc diffusion | E. coli (ATCC 25922), A. baumannii (ATCC 19606), P. aeruginosa (ATCC 27853), B. subtilis (ATCC 6633), S. aureus (ATCC 25923), and S. aureus (MRSA) | 190 |
| calcium alginate–nanocrystalline silver | Porcine ex vivo | P. aeruginosa (biofilm) | 207 |
| cotton gauze–silver sulphate | Porcine ex vivo | P. aeruginosa (biofilm) | 207 |
| hydrocolloid–silver | Porcine ex vivo | P. aeruginosa (biofilm) | 207 |
| polyacrylate–silver chloride | Porcine ex vivo | P. aeruginosa (biofilm) | 207 |
| silver dressings | Prevention of sedimentation biofilm formation measured by crystal violet—not quantitative—1 cm2 dressing added to bacterial suspension—biofilm formation measured by crystal violet | P. aeruginosa, S. aureus, E. coli, A. baumannii | 168 |
| keratin biomaterial containing AgNPs | Lysogeny broth solid plates and shake-flask method. Non-standard | E. coli C600, S. aureus RN4220, B. subtilis YB886 | 193 |
| silver nanocoating | Non-standard. Immersing dressing in solution, adding bacterial inoculum for 16 h at 37°C, removing dressing and recovering bacteria from the dressing | S. aureus ATCC 25923 and P. aeruginosa ATCC27853 | 206 |
| silver-containing crosslinked poly (acrylic acid) fibres | Zone inhibition—non-standard | MRSA USA 300 | 192 |
| various commercially available silver dressings | Shake flask assay: inoculum in the presence of dressing for 1–6 h at 37°C + use of neutralizer | P. aeruginosa ATCC 27312 and ATCC 15442, S. aureus ATCC 6538 | 201 |
| silver-containing dressing | Zone of inhibition on seeded agar + dressing in broth for up to 24 h at 35°C | S. aureus, B. subtilis, E. coli, P. aeruginosa. | 191 |
| antimicrobial polyur ethane foam dressing containing silver | Porcine ex vivo (loin roast) | S. aureus (DSM 20231) | 209 |
| commercially available silver-containing dressings | CLSI disc diffusion assay + zone of inhibition on seeded agar (some selective agar was used) | S. aureus (PCM 2051), S. epidermidis (PCM 2118), P. aeruginosa (ATCC 27853), E. coli (K12) | 194 |
| PHMB | |||
| PHMB | CLSI disc diffusion | E. coli (ATCC 25922), A. baumannii (ATCC 19606), P. aeruginosa (ATCC 27853), B. subtilis (ATCC 6633), S. aureus (ATCC 25923) and S. aureus (MRSA) | 190 |
| cotton gauze PHMB | Porcine ex vivo | P. aeruginosa (biofilm) | 207 |
| PHMB | Porcine ex vivo | P. aeruginosa (biofilm) | 190 |
| antimicrobial gauze dressing containing polihexanide | Porcine ex vivo (loin roast) | S. aureus (DSM 20231) | 209 |
| OCT | |||
| OCT | Non-standard broth dilution | S. aureus | 202 |
| Direct contact test (according to JIS L 1902:2002) | S. aureus | 202 | |
| non-antimicrobial poly urethane foam dressing intermittently irrigated with octenidine | Porcine ex vivo (loin roast) | S. aureus (DSM 20231) | 209 |
| Honey | |||
| L-Mesitran Soft | Non-standard ex vivo test on human skin | P. aeruginosa | 208 |
| iodine, calcium alginate Leptospermum honey | Porcine ex vivo | P. aeruginosa (biofilm) | 207 |
| Leptospermum honey | Porcine ex vivo | P. aeruginosa (biofilm) | 207 |
| 3 medical-grade honeys: Surgihoney RO, Activon manuka honey and Medihoney manuka honey | Prevention of sedimentation biofilm formation measured by crystal violet—not quantitative—diluted concentration of honey used | P. aeruginosa, S. aureus, E. coli, A. baumannii | 168 |
| honey-based dressings | Prevention of sedimentation biofilm formation measured by crystal violet—not quantitative—1 cm2 dressing added to bacterial suspension—biofilm formation measured by crystal violet | P. aeruginosa, S. aureus, E. coli, A. baumannii | 168 |
| chestnut honey- impregnated CMC hydrogel | Zone of inhibition on seeded agar | E. coli and S. aureus | 195 |
| honey-loaded nanofibre membrane | Non-standard broth evaluation by OD in the presence of material | E. coli | 201 |
| honey-loaded nanofibre membrane | Biofilm formation evaluated by crystal violet in presence of materials—non-standard and non-quantitative | E. coli | 201 |
| nano-composite alginate gel discs containing honey | Coated discs in inoculate broth for 24 h at 37°C | S. aureus (ATCC 6538) and MRSA (ATCC 43300), A. baumannii (ATCC 19606) + 13, carbapenem- resistant strains, E. coli (ATCC 10536) and P. aeruginosa (ATCC 9027) + 1 wound isolate | 200 |
| commercially available manuka honey-containing dressings | CLSI disc diffusion assay + zone of inhibition on seeded agar | S. aureus (PCM 2051), S. epidermidis (PCM 2118), P. aeruginosa (ATCC 27853), E. coli (K12) | 194 |
CMC, carboxymethyl cellulose.