Methicillin-resistant Staphylococcus aureus (MRSA) and anti-MRSA activities of extracts of some medicinal plants: A brief review

The increasing emergence of multidrug-resistant infection causing microorganisms has become a significant burden globally. Despite the efforts of pharmaceuticals in producing relatively new antimicrobial drugs, they have resulted in a high rate of mortality, disability and diseases across the world especially in developing countries. Supporting this claim was the report of the Centre for Disease Control and Prevention (CDC) who estimated that over 2 million illnesses and 23,000 deaths per year are attributable to antibiotic resistant pathogens in the United States. They include Methicillin-resistant Staphylococcus aureus (MRSA), Vancomycin-intermediate Staphylococcus aureus (VISA), Vancomycin-resistant Staphylococcus aureus (VRSA), Vancomycin-resistant enterococci (VRE), Extended spectrum beta-lactamases (ESBLs) producing gram-negative bacilli, Multidrug-resistant Streptococcus pneumoniae (MDRSP), Carbapenem-resistant Enterobacteriaceae (CRE) and Multidrug-resistant Acinetobacter baumannii. For MRSA, resistance is as a result of Methicillin-sensitive S. aureus (MSSA) strains that have acquired Staphylococcal Cassette Chromosome mec (SCCmec) which carries mecA gene. The gene encodes the penicillin-binding protein (PBP2a) which confers resistance to all β-lactam antibiotics. Vancomycin was previously the widely preferred drug for the treatment of MRSA infections. It is no longer the case with the emergence of S. aureus strains with reduced vancomycin sensitivity limiting the conventional treatment options for MRSA infections to very scanty expensive drugs. Presently, many researchers have reported the antibacterial activity of many plant extracts on MRSA. Hence, these medicinal plants might be promising candidates for treatment of MRSA infections. This work is a brief review on Methicillin-resistant Staphylococcus aureus (MRSA) and the anti-MRSA activities of extracts of selected medicinal plants.