The effects of an occlusive zinc medicated dressing on the bacterial flora in excised wounds in the rat

Abstract

The effects of three different dressings - two occlusive and one non-occlusive - on the bacterial flora of excised wounds in rats were studied. The number of colony forming units per gram of granulation tissue were significantly lower 4, 8 and 12 days postoperatively in wounds treated with a zinc medicated occlusive dressing compared with wounds treated with non-zinc medicated occlusive hydrocolloid dressing or wet-to-dry non-occlusive gauze dressing. The minimum inhibitory concentration (MIC) of zinc sulphate was determined on different strains of bacteria isolated from the wounds of rats and on strains isolated from humans. The most susceptible species isolated from both rat wounds and humans were Streptococcus sp., STaphylococcus aureus and Escherichia coli; whereas, Proteus and Enterococcus sp. had higher MIC-values. In vitro, the hydrocolloid dressing disclosed no antibacterial effects. If the practitioner prefers an occlusive dressing we believe, due to our animal and in vitro experiments, that the zinc medicated occlusive dressing will reduce the risk of wound infection in man.

Zinc in wound healing: Theoretical, experimental, and clinical aspects

“…For example, minimum inhibitory concentrations (MICs) of Zn 21 on aerobic bacteria isolated from human wound infections were determined in one study. 173 Four susceptibility grades emerged from the study: Similar sensitivity patterns were observed for clinical isolates from burn wounds. 174 Zinc oxide also showed antibacterial activity against aerobic and anaerobic endodontal pathogens.…”

“…Gram‐positive organisms appear to be more sensitive to zinc than Gram‐negative bacteria. For example, minimum inhibitory concentrations (MICs) of Zn 2+ on aerobic bacteria isolated from human wound infections were determined in one study 173 . Four susceptibility grades emerged from the study:…”

“…Thus, as zinc supplements possess mild antimicrobial properties against common wound flora 173 and aid a host's defense system against infections, 178 consideration might usefully be given to zinc products in wound care.…”

Enhanced Healing of Surgical Wounds of the Lower Leg Using Weekly Zinc Oxide Compression Dressings

“…Topical zinc oxide has also demonstrated significant antibacterial and antiinflammatory properties. In a rat model, occlusive zinc dressings inhibited growth of Gram‐positive organisms, including Staphylococcus aureus and Streptococcus groups A, B, C, and G 19 . Burn wounds in human patients treated with topical zinc have also demonstrated less growth of S. aureus 20 .…”

Deposition of antimicrobial coatings on microstereolithography-fabricated microneedles

“…21,22 Soderberg et al obtained minimum inhibitory concentration data for human wound infection-derived bacteria that were exposed to Zn +2 . 23 Different susceptibility rates were noted for Enterococcus sp., Proteus sp., Pseudomonas aeruginosa, (MICs of 8-32 mmol/L); Enterobacter sp., Escherichia coli, Klebsiella sp. (MICs of 4-8 mmol/L); Staphylococcus aureus, Streptococcus group B (MICs of 2-4 mmol/L); and Streptococcus groups A, C, and G (MICs of 0.5-2 mmol/L).…”