Interkingdom Biofilms Are Affected by Non-Antibiotic Strategies: In Vitro Study in Lubbock Chronic Wound Biofilm Model

Chronic wound infections associated with resistant polymicrobial biofilms are often refractory to conventional therapies with sustained healing time. This study evaluated the efficacy of non-antibiotic treatments including Methylglyoxal-MGO-Light-Emitting Diode-LED-and Complex Magnetic Fields-CMFs-alone/combined against the biofilms of two polymicrobial mixes (MIX 1, MIX 2) containing <i>S. aureus</i>, <i>P. aeruginosa</i> and <i>C. albicans</i> using the Lubbock chronic wound biofilm model. At 24 h after treatment, the effects were evaluated by (i) CFU/mg reduction, (ii) Confocal Laser Scanning Microscopy-CLSM-and (iii) Scanning Electron Microscopy-SEM. All treatments significantly reduced biofilms in terms of CFU/mg in both mixes versus the controls, 24 h after treatment. MGO showed remarkable activity, especially against <i>P. aeruginosa</i>. In MIX 1, LED/MGO + LED was highly effective against <i>C. albicans</i>. The combinations MGO + LED/MGO + CMFs enhanced the antibiofilm activity compared to each single treatment against <i>S. aureus</i> and <i>P. aeruginosa</i>, in both MIX1/MIX2. CLSM and SEM analysis showed biofilm disaggregation and reduction in cell viability with combined treatments, and <i>Candida</i> hyphal inhibition after CMFs application. In conclusion, the results demonstrate that MGO, alone or combined with LED or CMFs, shows high efficacy against resistant biofilms in the LCWB model 24 h after treatment, and encourage further studies on potential non-antibiotic and eco-friendly strategies as future alternative therapeutic approaches for chronic wound infections.