The Topical Formulations Of Staphyloccocus Aureus Bacteriophage Lysin LysGH15

Staphyloccocus aureus is widely distributed in nature，and as pathogenic bacteriait’s widespread in the skin and the respiratory tract of humans and animals.TheEmergence of methicillin-resistant Staphylococcus aureus bacteria in clinicaltreatment of infectious diseases brought great difficulties.And caused tremendousthreat for human and animal health. Phage lyase is a kind of protein that wasexpressed by phage at the end of infection, which by hydrolysis of bacterial cell wallpeptidoglycan make progeny phage released, thereby killing the bacteria.Therefore,phage lyase has great potential to become the new drugs which focus on infectionscaused by bacterial.Previous experiment obtained phage lysinGH15which shows highactivity and broad-spectrum，especially showed uniform and efficient lytic activity toresistant strains.In this study, we based on preliminary studies,to develop andoptimize the topical formulations.And to evaluate the therapeutic effect, therebylaying the foundation for the topical treatment of lyase GH15.Furthermore,using Staphylococcus aureus USA300established mouse model ofskin burn infections.The shaved skin area was then tape strippe,using autoclavetape.This allowed a significant portion of the epidermis to be removed and reddeningof the skin.The shaved/tape-stripped area of the mice was topically colonized withovernight cultures of S. aureus USA300.we found that using containing106to108bacteria cells could establish a satisfied mouse model of skin burn infections.Using gel to evaluate the therapeutic effect in mouse model cased byStaphylococcus aureus USA300,a4-log to5-log reduction with gel after7daystreatment as opposed to2-log reduction with buffer.the inflammatory cell in treatedmouse were significantly reduced，and the wound healed well.That showed the gel hasgood therapeutic effect in mouse model. In this study we successfully obtained gel of LysGH15,and shows safety andgood therapeutic effect in mouse model.as a result we initially identified phage lyaseLysGH15topical dosage forms and formulations laying the foundation for the topicaltreatment of lyase GH15.