Methicillin Resistance in Staphylococcus aureus: A Review of the Molecular Epidemiology, Clinical Significance and Laboratory Detection Methods

BACKGROUND: Despite the volume of knowledge, enhanced surveillance and infection control measures adopted by health care institutions to address the endemicity and frequent disease outbreaks by methicillin-resistant Staphylococcus aureus (MRSA) in hospitals and health care facilities worldwide, infections due to this organism are still responsible for about 50% of hospital acquired S. aureus infections, with increasing morbidity and mortality. OBJECTIVE: To provide regional clinicians with current information on the molecular epidemiology, laboratory detection and clinical aspects of MRSA. METHODS: A review of published literatures on MRSA in Medical Libraries and bibliographic citations on PubMed, Medline and Africa Index Medicus on molecular epidemiology and clinical diseases caused by MRSA and the assessment of the recent laboratory diagnostic approaches. RESULTS: This review showed that there has been intercontinental spread of some highly pathogenic clones of MRSA threatening to create public health hazard of unprecedented proportion, with the greatest challenge to mankind, being the development of resistance to multiple antibiotics, which in recent times had included resistance to vancomycin and other glycopeptides, the only antibiotic group effective against it. Added to this burden is the emergence of more virulent strains of community-associated MRSA (CAMRSA) which at the turn of the century, has been increasingly reported to cause infections and outbreaks in populations without predisposing risk factors, with attendant high morbidity and mortality. CONCLUSION: There is need for active MRSA surveillance by healthcare institutions in Africa to identify potential outbreaks, and vigilance in the enforcement of infection control measures such as rational prescription of antibiotics, handwashing, disinfection and sterilization that can limit the emergence and spread of more resistant clones of MRSA.