
In this experiment, the antimicrobial performance of the TrioMed conventional dressing was compared to that of a commercially available Silver-impregnated dressing. Both dressings were subjected to repeated challenges of Pseudomonas aeruginosa (averaging 7.2 X 107 CFU/ml) over 7 days. Results demonstrated that the TrioMed antimicrobial dressing consistently maintained a microbial-free wound dressing despite repeated inoculation over a 7 day period, thus outperforming the Silver-based device, which was unable not only to reduce the bacterial load in the wound but also supported consistent growth of the bacteria over the testing period.
In this experiment, the antimicrobial performance of the TrioMed Advanced dressing was compared to those of commercially available Silver and Iodine dressings with similar intended uses to serve as benchmark. All dressings were subjected to repeated challenges of Pseudomonas aeruginosa (averaging 1.0 X 108 CFU/ml) over 14 days. The TrioMed advanced antimicrobial dressings clearly demonstrated superior antimicrobial performance for this extended period of 14 days in relation to leading brands since it was the only wound dressing able to maintain a microbial-free wound dressing.
| Antimicrobial Dressing Type | Zone of Inhibition (mm) | Inhibition of Growth under the sample? |
|---|---|---|
| TrioMed Dressing (Iodine-based) | 6.85 | Yes (bactericidal) |
| Iodine Dressing A | 1.49 | Yes (bactericidal) |
| Silver Dressing A | NZ* | No (bacteriostatic) |
| Silver Dressing B | 1.20 | No (bacteriostatic) |
*NZ: No zone inhibition




The zone of inhibition test determines whether the antimicrobial agent applied to the dressing is able to inhibit bacterial growth. Based on the results displayed above, the TrioMed dressing showed excellent antibacterial activity against a challenge of methicillin-resistant Staphylococcus aureus (MRSA). Once again, it clearly outperformed commercially available dressings treated with Silver or Iodine. Moreover, the iodine-treated devices were bactericidal (it killed the bacteria) as opposed to the Silver-dressings which only inhibited the bacterial growth (bacteriostatic).
| Antimicrobial Dressing Type | Log Reduction in Pseudomonas aeruginosa | |
|---|---|---|
| 60 min incubation | 120 min incubation | |
| TrioMed (Iodine-based) | >5.00* | >5.55§ |
| Silver Dressing A | 0.00 | 1.03 |
| Silver Dressing B | 0.00 | 0.61 |
*Detection Level = 50 CFU
§Detection Level = 16.7 CFU
The Log test or bacterial reduction test determines the ability of the dressings to kill the microbial challenge applied directly to their surfaces. After 60 and 120 minutes, viable bacterial counts remaining on the dressings are determined for each dressing type. Results demonstrated that the TrioMed dressing reduced the P. aeruginosa challenge to non-detectable levels within 60 minutes. Very low bacterial reduction levels were measured for the two silver-based dressings used for comparison.