Table 3.
Antimicrobial efficacy after 72 hours of continuous exposure to dressings on mature PA01 biofilms*
| A: 72‐Hour exposure | Mean log CFU/ml | 95% CI log CFU/ml | Log reduction† | Significance |
|---|---|---|---|---|
| Before treatment (0 hour) | 7·076 | 6·221–7·931 |
0·694a 0·079b |
ns ns |
| No dressing | 7·155 | 6·616–7·694 |
0·615a –b |
ns – |
| Wet gauze | 7·770 | 7·154–8·386 |
–a −0·615b |
– ns |
| Algisite®‐M (Ca Alginate) | 10·270 | 9·838–10·71 |
−2·505a −3·12b |
*** *** |
| Aquacel® (NaCMC) | 8·193 | 7·565–8·820 |
−0·423a −1·038b |
ns ns |
| Acticoat®‐Absorb (Ca Alginate‐NanoAg) | 8·024 | 7·524–8·524 |
−0·254a −0·869b |
ns ns |
| Medihoney®‐Ca alginate pad | 7·554 | 7·460–7·648 |
0·216a −0·399b |
ns ns |
| Medihoney ointment | 7·418 | 7·164–7·671 |
0·352a −0·263b |
ns ns |
| Curity™ AMD (PHMB gauze) | 7·305 | 6·861–7·749 |
0·465a −0·15b |
ns ns |
| Tegaderm‐AgMesh (Ag Sulphate gauze) | 7·376 | 6·812–7·939 |
0·394a −0·221b |
ns ns |
| Aquacel‐Ag (NaCMC‐Ag) | 6·969 | 6·511–7·427 |
0·801a 0·186b |
ns ns |
| Povidone‐iodine (PVP‐I) | 6·657 | 5·952–7·363 |
1·113a 0·498b |
ns ns |
| 4% Ethanol (ETOH) | 6·485 | 6·162–6·807 |
1·285a 0·671b |
ns ns |
| Acticoat 7 (Polyethylene‐NanoAg) | 6·460 | 5·741–7·178 |
1·31a 0·695b |
ns ns |
| Cadesorb® (cadexomer) | 6·470 | 5·324–7·616 |
1·3a 0·685b |
ns ns |
| Silvasorb® gel (Polyacrylate–AgCl) | 2·137 | 0·3237–3·95 |
5·633a 5·018b |
*** *** |
| Iodoflex™ (100% cadexomer iodine) | 0 | 0–0 |
7·77a 7·155b |
*** *** |
| B: 72‐Hour exposure | Mean log CFU/ml | 95% CI log CFU/ml | Log reduction ‡ | Significance |
| Cadesorb (cadexomer)a | 6·470 | 5·324–7·616 | – | – |
| Iodoflex (100% cadexomer iodine) | 0 | 0–0 | 6·470a | *** |
| Algisite‐M (Ca Alginate)b | 10·27 | 9·838–10·71 | – | – |
| Acticoat‐Absorb (Ca Alginate‐NanoAg) | 8·024 | 7·524–8·524 | 2·251b | *** |
| Medihoney alginate pad | 7·554 | 7·460–7·648 | 2·716b | *** |
| Aquacel (NaCMC)c | 8·193 | 7·565–8·820 | – | – |
| Aquacel‐Ag (NaCMC‐Ag) | 6·969 | 6·511–7·427 | 1·223c | ** |
CFU, colony‐forming unit; CI, confidence interval.
All biofilms were cultured for 3 days on porcine explants and pre‐treated for 24 hours with high antibiotic immersion treatment to kill planktonic bacteria before dressing application, including the before treatment (0 hour) condition. Microbial load reduction due to antimicrobial dressings (single application) was compared to (A) wet gauze or no dressing control or (B) companion (vehicle alone) dressing control.
Compared to awet (ddH20) gauze control or bno dressing control.
Compared to companion dressing as indicated in each demarcated set a,b,c.
* = (0·01 ≤ P < 0·05), ** = (0·001 ≤ P < 0·01), *** = (P < 0·001) and ns = (P ≥ 0·05).