In Vitro and in Vivo Antistaphylococcal Activity Determination of the New Recombinant Lysostaphin Protein.

Abstract

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 × 109 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.