Evaluation of antibiotic activity of methicillin in healing of fullthickness infected wounds with sensitized methicillin resistant Staphylococcus aureus in the presence of HAMLET

Objective(s): The novel healing choices for handling of infections due to multidrug resistant Staphylococcus aureus are reguired. HAMLET has been reported to be able to sensitize bacterial pathogens to traditional antimicrobial agents. The aim was to assess wound healing activity of methicillin in presence of HAMLET in methicillin resistant S. aureus (MRSA) infected wounds. Materials and Methods: Fifty male rats were randomized into five groups of ten animals each. In CONTROL group, 0.1 ml sterile saline 0.9% solution was added to the wounds with no infection. In MRSA group, the wounds were infected with MRSA and only treated with 0.1 ml the sterile saline (0.9%) solution. In MRSA/HAMLET group, infected wounds were cured with HAMLET (100 μg). In group MRSA/ Met, animals with infected wounds were cured with 0.1 ml local use of 1 mg/ml methicillin. In MRSA/Met/HAMLET group, animals with infected wounds were cured with local use of 0.1 ml solution of methicillin (1 mg/ml) and HAMLET (100 μg). All test formulations were used for ten consecutive days, twice a day, beginning from first treatment. Results: Microbiological examination, planimetric, histological and quantitative morphometric studies, immunohistochemical staining for angiogenesis, determination of hydroxyproline levels and RT-PCR for Caspase 3, Bcl-2 and p53 showed that there was significant difference between animals in MRSA/Met/ HAMLET group compared to other groups (P<0.05). Conclusion: HAMLET could make methicillin beneficial for handling of MRSA infected wounds and had the prospective effect to consider this harmless agent for local application.