preview

Staphylococcus Aureus ( Mrsa )

Decent Essays

Background
Staphylococcus aureus is a gram-positive, cluster forming bacterium which shows positive results in catalase and nitrate reduction tests. It is considered as a harmful pathogen for human and animal beings and has resistance to many classes of antimicrobial agents. The most important example is methicillin-resistant Staphylococcus aureus (MRSA), the first clinical isolate, reported at the end of 1960, within a year after the introduction of methicillin (Jevons et al., 1963). Afterwards, it has been frequently disseminated throughout the world and reported serious hospital associated infections in 1970s.Several MRSA clones have emerged in past four decades, but major hospital-acquired MRSA (HA-MRSA)clones identified in five accepted clonal lineages by population genetic studies. Genotypes within these lineages have developed resistance to all known antibiotics. Besides, some significant risk factors, like surgery, recent hospitalization and antimicrobial treatment have potential roles in HA-MRSA infection in patients.

While MRSA primarily confined to hospitals and patients along with defined risk factors, reports on community-associated MRSA (CA-MRSA) in patients began to publish in early 2000s (Zetola et al., 2005). CA-MRSA isolates identified as a rapidly emerging pathogen and frequently occurred in previously healthy individuals without the risk factors for HA-MRSA. CA-MRSA isolates are much more virulent than HA-MRSA that cause rapid tissue necrosis and

Get Access