The Antibacterial Activity of a Novel Biomaterial Against Key Wound Pathogens: Staphylococcus aureus and Pseudomonas aeruginosa

Aim: The colonization of a wound by microorganisms typically occurs as a continuum extending from contamination, to colonization, and infection. The predominant microbial species observed within infected wounds of patients include Staphylococcus aureus and Pseudomonas aeruginosa. Biomaterials that demonstrate bacteriostatic or antimicrobial activity can control or reduce the bioburden associated with delayed wound healing. In this study, a novel biomaterial containing gelatin, Manuka honey, and hydroxyapatite, was evaluated for in vitro antibacterial properties.

Method: The novel biomaterial was prepared according to the manufacturer's instructions. S. aureus and P. aeruginosa suspensions were used to inoculate test and control samples. Samples we incubated for 30 minutes and 24 hours at 37°C2°C. Remaining organisms were recovered by sonication and resultant suspensions were serially diluted. Dilutions were plated onto agar and incubated for 24 hours 37°C2°C.

Results: An average of 4.610.04 and 6.850.19 Log10CFUmL-1 S. aureus were recovered from the negative control material following 30 minutes and 24 hours incubation respectively. Following 24 hours incubation with the novel biomaterial, an average of 2.890.19 Log10CFUmL-1 S. aureus was recovered. This was an average reduction of 1.60 Log10CFUmL_1 compared to the biomaterial after 30 minutes incubation. An average of 4.830.10 and 8.420.05 Log10CFUmL-1 P. aeruginosa were recovered from the negative control material following 30 minutes and 24 hours incubation respectively. Following 24 hours incubation with the novel biomaterial, an average of 4.210.03 Log10CFUmL-1 P. aeruginosa was recovered. The recovery at 24 hours was comparable to the recovery at 30 minutes suggesting a bacteriostatic effect.

Conclusion:  Treatment with the novel biomaterial resulted in a reduction of S. aureus and prevented growth of P. aeruginosa over 24 hours suggesting that the product can help manage the pathogenic bioburden associated with infected wounds.