Antibacterial effect of red light emitting diodes on multi-drug resistant bacteria isolated from superficial skin infections

Abstract

Abstract Background Emergence of multi-drug resistant bacteria in current times demands for concerted efforts, specifically in developing countries to replace the administration of antibiotics with other therapeutic modalities as photodynamic inactivation using red light emitting diodes. Aim Isolate and identify pathogenic bacteria from superficial skin infections, determine antibiotic susceptibility of isolated bacteria and to evaluate antibacterial role of red light emitting diodes on multi-drug resistant isolates using different durations. Patients and methods Fifty patients with superficial skin infection were enrolled in the present study. Isolation and identification were carried out by standard microbiological methods. Antibacterial susceptibility tests of the isolates were assessed by disc diffusion method. The multi-drug resistant isolates were illuminated by red light emitting diodes for different durations at 10, 20, 30 and 60 min Then antibacterial effect was assessed by colony count. Results Illumination with red light emitting diodes showed antibacterial effect in all isolates with variable degrees. There were initial reduction in colony count after 10 min followed by a slight increase in colony count with increasing the duration of illumination. Staphylococcus aureus isolates showed the lowest reduction in log10CFU/ml-1 with mean±SD of 5.14 ± 0.06 after 10 min. Conclusion The photodynamic inactivation using red light emitting diodes showed significant reduction in colony count when multi-drug-resistant isolates were illuminated for 10 min suggesting its potential for use as antibacterial therapeutic modality.