Membranas bioadhesivas antibiótico-anestésicas: evaluación in vitro de la actividad antibiofilm en cepas de relevancia clínica

BARBIERI FIAMMA; BECERRA MC; OLIVERA ME

Rosario

Congreso; VII reunion RICIFA; 2023

Univ. Nac. de Rosario y UNC

Chronic skin wound infections slow the healing process and cause increased pain. In a previous stage, a bioadhesive antibiotic-anesthetic membrane (BAAM) containing sodium hyaluronate (Hy), sodium alginate (SA), ciprofloxacin (Cip), lidocaine (Lid) and glycerin (Gly) was developed. The objective of this study was to evaluate the antibiofilm activity of individual BAAM components, as well as in combination, against clinically relevant strains. Sixteen treatments were prepared according to the following combination criteria: all components; all components in the absence of one; SA, Hy and Gly in the absence of active ingredients (API); the API in the absence of SA, Hy and Gly and the combination of the API with SA, Hy and Gly individually. Two clinical strains were selected: methicillin-resistant Staphylococcus aureus 9455 and Pseudomonas aeruginosa 19115. Biofilm formation was determined by crystal violet (CV) staining and absorbance reading at 595 nm (n=3). The antibiofilm effect of the treatments was evaluated against immature biofilms (4 and 8 h of induction of the inoculum prior to treatment) and against the inoculum without induction time (planktonic state). BAAM without inoculum was used as negative control (C-) and the untreated inoculum as positive control (C+). The average absorbance of biofilm formation at 0, 4 and 8 h was plotted for each strain. The results were statistically analyzed by applying the one-way ANOVA test. The results showed that the treatments containing Cip significantly inhibited the biofilm formation of both strains at each induction time and there were no significant differences between the treatments containing Cip alone with respect to Cip and its combinations, which show that the rest of the components do not affect their activity. In addition, SA showed activity against both strains at 0, 4 and 8 h of biofilm induction, with the same significance as Cip alone, this being a novel result. Hy did not show significant inhibition of biofilm formation against any of the strains; although there is bibliography that describes an antibiofilm effect of Hy, the concentration evaluated was 10 times higher than that evaluated in this work. Lid did not show activity against S. aureus, but it did against P. aeruginosa at 4 and 8 h of biofilm induction. Antimicrobial activity has been described in the bibliography, but not antibiofilm activity. Gly has shown a significant reduction in the biomass of the P. aeruginosa biofilm at 0 and 4 h of induction. Antimicrobial activity of Gly against these pathogens has been described, but at a concentration 80 times higher than that evaluated in this work. The results show that the combination of Cip with the other components does not interfere with its antibiotic and antibiofilm activity. Likewise, an antibiofilm effect of SA was observed against both strains and of Lid and Gly against P. aeruginosa, which would represent a novel and additional beneficial effect in addition to the main function they fulfill in the formulation.