Evaluate the effect of Protoparmeliopsis muralis on icaA gene expression in Methicillin-Resistant Staphylococcus aureus isolated from burn wound

BACKGROUND AND OBJECTIVESNowadays, the emergence and alarming rise of multidrug resistant pathogenic bacteria is becoming a serious health challenge. So, there is an urgent need to obtain novel ingredients with antimicrobial activity. In this regard, lichens are promising substance with antimicrobial potential to control different microbial strains such as fungi, gram-positive/-negative bacteria and viruses. In this study we aimed to determine the use of Protoparmeliopsis muralis in the treatment of burn wound infection.MATERIALS AND METHODSTwenty-four Methicillin-Resistant Staphylococcus aureus isolates were recovered from burn wound infections of patients admitted to the burn ward of Besat hospital of Hamadan, Iran, during ۲۰۲۲. The minimum inhibitory concentration (MIC) of Protoparmeliopsis muralis was determined by microdilution broth method. The effect of MIC and sub-MIC concentrations of this extract on biofilm formation was determined by the microtiter plate method (MTP). Also, the expression level of the icaA gene was assessed by Real-Time PCR technique.RESULTS AND DISCUSSIONAccording to the results, the extract from Protoparmeliopsis muralis demonstrated MIC and MBC at a concentration of ۶۲۵ μg/ml and ۱۲۵۰ μg/ml for MRSA isolates. Additionally, this extract demonstrated ۷۳% biofilm formation inhibition. Also, bacterial cells exposed to Protoparmeliopsis muralis showed ۱fold down-regulations of icaA gene expression levels.CONCLUSIONThis study showed the important role of Protoparmeliopsis muralis in enhancing antibacterial and antibiofilm activity which can be used in the prevention of biofilm established by MRSA in vitro models.