Effectiveness of Pyruvate Dehydrogenase Enzyme (PDH) in the Dispersion of Established Biofilms of Pseudomonas Aeruginosa (ATCC 27312) Using a Deep Partial Thickness Porcine Wound Model

Background: Pseudomonas aeruginosa (PA) is a gram-negative microorganism with a high capability of forming biofilm. New technologies have been developed to either prevent biofilm from forming or to eliminate it, wounds colonized by this type of bacteria are very difficult to treat, leading to a delay in wound healing. Evidence shows that PA requires pyruvate in order to form biofilms, and that pyruvate depletion depends on the pyruvate dehydrogenase enzyme (PDH) when inducing biofilm dispersion.

Purpose: This study examined the effect of PDH to disperse established biofilms to improve the efficacy of Tobrmycin.

Methods: Deep partial thickness wounds were created on the back of three pigs. Wounds were inoculated with PA (ATCC 27312) and treated after 24 hours biofilm formation. Wounds were randomly assigned to one of six treatment groups: 1) PDH 100mU, 2) PDH 100mU + Tobramycin (100ug/ml), 3) PDH 200mU, 4) PDH 200mU + Tobramycin (100ug/ml), 5) Positive Control Tobramycin (100ug/ml) and 6) Untreated Control. Wounds were assessed on days 3 and 6 (microbiology).

Results: Results showed that wounds treated with PDH 200mU + Tobramycin (100ug/ml) reduced the most PA (planktonic and biofilm) throughout the study on both assessment days. On day 6, this treatment exhibited bacterial reduction of 4.48 and 4.14 Log CFU/ml compare to baseline and untreated control, respectively (Planktonic) and 3.62 and 3.65 Log CFU/ml (Biofilm). Results suggest that PDH 200mU + Tobramycin (100ug/ml) treatment is beneficial for controlling infection in wounds colonized with PA.

Conclusion: Additional well-controlled studies examining their potential use are warranted.