Jianhua Huang1, Qing Fan2, Mingquan Guo3, Minfeng Wu1, Shutian Wu1, Shuzhan Shen4, Xiuli Wang4, Hongwei Wang4. 1. Department of Dermatology, Huadong Hospital, Fudan University, Shanghai 200040, PR China. 2. Department of Dermatology, Shanghai Fengxian District Hospital, Shanghai (201499), PR China. 3. Shanghai Institute of Bacteriophage and Drug Resistance, Shanghai Public Health Clinical Center, Fudan University, Shanghai 201514, PR China. 4. Shanghai Skin Disease Hospital, Institute of Photomedicine, Tongji University School of Medicine, Shanghai, PR China.
Abstract
OBJECTIVE: This study sought to estimate the effect of a liquid octenidine dihydrochloride (OCT)-impregnated gauze dressing in the treatment of meticillin-resistant Staphylococcus aureus (MRSA) biofilm-infected wounds. METHOD: In this animal study, a six-millimetre punch full-thickness wound on each mouse back was inoculated with MRSA suspension, and then covered with a Tegaderm (3M Health Care, US) dressing for an established biofilm model. Animals were divided into three groups for topical application: control group (treated with phosphate-buffered saline, PBS); mupirocin group (treated with 2% mupirocin); and OCT group (treated with OCT). All applications were administrated once 24 hours post-wounding. The bioburden was determined by counting colony-forming units (cfus) and the biofilm architecture was viewed using fluorescent staining and scanning electron microscopy (SEM) on day two. The tissue repair was evaluated histologically and the related genes were detected by reverse transcription quantitative polymerase chain reaction (RT-qPCR) on day 15. RESULTS: The results suggested OCT accelerated healing and reduced by >3.6 log cfu/g bacterial counts on the wounds relative to the PBS-treated control (p<0.05). Histological analysis showed OCT-treated tissue exhibited lower burden of the inflammatory cells, more mature collagen fibres and well-defined epithelialisation. LIVE/DEAD fluorescent staining and SEM confirmed OCT induced a substantial destruction to biofilm structure. RT-qPCR further demonstrated that OCT therapy could inhibit the expression of MRSA and its biofilm genes by nearly 100% (p<0.05). CONCLUSION: This investigation provides a rare in vivo experimental basis for OCT improvement on MRSA-infected wound healing and the superior efficacy implies OCT topical application may represent an ideal choice to address established bacterial biofilm in hard-to-heal wounds.
OBJECTIVE: This study sought to estimate the effect of a liquid octenidine dihydrochloride (OCT)-impregnated gauze dressing in the treatment of meticillin-resistant Staphylococcus aureus (MRSA) biofilm-infected wounds. METHOD: In this animal study, a six-millimetre punch full-thickness wound on each mouse back was inoculated with MRSA suspension, and then covered with a Tegaderm (3M Health Care, US) dressing for an established biofilm model. Animals were divided into three groups for topical application: control group (treated with phosphate-buffered saline, PBS); mupirocin group (treated with 2% mupirocin); and OCT group (treated with OCT). All applications were administrated once 24 hours post-wounding. The bioburden was determined by counting colony-forming units (cfus) and the biofilm architecture was viewed using fluorescent staining and scanning electron microscopy (SEM) on day two. The tissue repair was evaluated histologically and the related genes were detected by reverse transcription quantitative polymerase chain reaction (RT-qPCR) on day 15. RESULTS: The results suggested OCT accelerated healing and reduced by >3.6 log cfu/g bacterial counts on the wounds relative to the PBS-treated control (p<0.05). Histological analysis showed OCT-treated tissue exhibited lower burden of the inflammatory cells, more mature collagen fibres and well-defined epithelialisation. LIVE/DEAD fluorescent staining and SEM confirmed OCT induced a substantial destruction to biofilm structure. RT-qPCR further demonstrated that OCT therapy could inhibit the expression of MRSA and its biofilm genes by nearly 100% (p<0.05). CONCLUSION: This investigation provides a rare in vivo experimental basis for OCT improvement on MRSA-infected wound healing and the superior efficacy implies OCT topical application may represent an ideal choice to address established bacterial biofilm in hard-to-heal wounds.