in vitro and in vivo antistaphylococcal activity determination of the new recombinant lysostaphin protein

Background: bacterial infection by antibiotic-resistant staphylococcus aureus strains is a worldwide concern and the development of novel antistaphylococcal agents is acutely needed. lysostaphin, an example of such novel agents, is a bacteriocin secreted by s. simulans to kill s. aureus through proteolysis of the staphylococcus cell wall. objectives: the aim of this study was to evaluate the in vitro and in vivo antistaphylococcal activity of recombinant lysostaphin. materials and methods: the in vitro study of the recombinant lysostaphin activity against s. aureus was determined by turbidimetric assay. for in vivo investigation, two groups of rats were inoculated with 1.4 × 10^9 cfu s. aureus. five days after the nasal instillation of s. aureus, treatment in one of the groups was performed with a single dose (200 μg/dose) of recombinant lysostaphin formulated in eucerin-based cream. results: recombinant lysostaphin at 100 μg/ml concentration showed a significant decrease of the optical density compared to the control samples. the in vivo study demonstrated that a single dose (200 μg/dose) of recombinant lysostaphin cream significantly reduced nasal colonization in all the treated animals compared to the untreated ones. conclusions: these results demonstrated that the recombinant lysostaphin produced in this study was able to kill nasal s. aureus in rats. it can be recommended for human clinical trial studies.