Future scope of plant-derived bioactive compounds in the management of methicillin-resistant Staphylococcus aureus: in vitro antimicrobial and antivirulence prospects to combat MRSA

Methicillin-resistant Staphylococcus aureus (MRSA)is a foremost human and animal pathogen with public health and veterinary significance causing hospital and community infections and contagious bovine mastitis. Due to its ability to develop multidrug resistance (MDR)and its pathogenicity, MRSA infection control is becoming a global concern. Natural antibacterial options are needed to combat MDR development and infectious dissemination. This study investigated the antimicrobial resistance and virulence genes profiling of MRSA isolates and explored the antivirulence efficacy of trans-cinnamaldehyde, thymol, and carvacrol essential oils (EOs)against multivirulent and MDR-MRSA isolates. Thirty six S. aureus isolates (25 percent)were retrieved, of which 34 (94.4 percent)were MRSA. A high prevalence of MDR (66.7 percent)was monitored and all 53 molecularly verified isolates possessed icaA and cna virulence genes. Moreover, 94.1 percent of these isolates were multivirulent with 23.5 percent of them carrying icaA, cna, eta, tst, and sea virulence genes. Our data proved superior in vitro antimicrobial and antivirulence activities of trans-cinnamaldehyde, thymol, and carvacrol. They inhibited the growth of multi-virulent and MDR-MRSA isolates and downregulated the transcription of examined virulence genes. Our study suggests using EOs as prospective antimicrobials with excellent antivirulence activities against MRSA isolates. We provided data regarding the eventual role of phytogenics in prevention and control of MRSA infection.