Effect of Tranexamic Acid against Staphylococcus spp. and Cutibacterium acnes Associated with Peri-Implant Infection: Results from an In Vitro Study

Tranexamic acid (TXA) is extensively used in orthopedic surgery and traumatology as an antifibrinolytic agent to control intra- and postoperative bleeding and, therefore, indirectly, to reduce postsurgery infection rates. The hypothesis of an additional antibiotic effect against microorganisms associated with periprosthetic joint infection needs to be further evaluated. We aimed to assess whether TXA could reduce bacterial growth using an in vitro model. ATCC and clinical strains of staphylococci and Cutibacterium acnes were tested against TXA in both planktonic and sessile forms. We recorded the percent reduction in the following variables: log CFU/mL by microbiological culture, percentage of live cells by confocal laser scanning microscopy, and, additionally in sessile cells, metabolic activity by the 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide salt (XTT) assay. Variables were compared between groups using the Kruskal-Wallis test, and the results were reported as median (interquartile range [IQR]). Statistical significance was set at a P value of <0.05. Clinical significance was defined as a reduction of ≥25%. TXA at 50 mg/mL led to a slight reduction in CFU counts (4.5%). However, it was at 10 mg/mL that the reduction reached 27.2% and 33.0% for log CFU/mL counts and percentage of live cells, respectively. TXA was not efficacious for reducing preformed 24-h mature staphylococci and 48-h mature C. acnes biofilms, regardless of its concentration. TXA did not exert an antimicrobial effect against bacterial biofilms. However, when bacteria were in the planktonic form, it led to a clinically and statistically significant reduction in bacterial growth at 10 mg/mL. IMPORTANCE The possible use of TXA as an antibiotic agent in addition to its antifibrinolytic effect may play an important role in the prevention of prosthetic joint infection.