Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA): molecular background, virulence, and relevance for public health

Bonesso MF (1, 2), Marques SA (3), Cunha MLRS (1)

(1) Department of Microbiology and Immunology, Botucatu Biosciences Institute, São Paulo State University (UNESP - Univ Estadual Paulista), Botucatu, São Paulo State, Brazil; (2) Department of Tropical Diseases, Botucatu Medical School, São Paulo State University (UNESP - Univ Estadual Paulista), Botucatu, São Paulo State, Brazil; (3) Departament of Dermatology e Radiotherapy, Botucatu Medical School, São Paulo State University (UNESP - Univ Estadual Paulista), Botucatu, São Paulo State, Brazil.

Abstract: Staphylococcus aureus and coagulase-negative Staphylococcus (CoNS) are frequently found in nosocomial environments as the main pathogen in several infections. In 1961, reports of nosocomial S. aureus resistant to methicillin, the drug of choice against penicillin-resistant strains, required new alternatives and vancomycin started being used to treat infections caused by methicillin-resistant S. aureus (MRSA). Community-acquired methicillin-resistant S. aureus (CA-MRSA) was first reported in 1990 affecting patients without risk factors for infection with MRSA of hospital origin. MRSA of community origin harbor the genes responsible for the synthesis of Panton-Valentine leukocidin (PVL), a toxin associated with skin and soft tissue infections and that carries the staphylococcal cassette chromosome mec (SCCmec) type IV. CA-MRSA emergence has caused great impact on the worldwide medical community since the presence of this pathogen in patients without risk factors represents a high risk to public health.

Key words: methicillin-resistant Staphylococcus aureus, mecA gene, oxacillin, Panton-Valentine leukocidin, drug resistance, epidemiology.

ACKNOWLEDGEMENTS

We are grateful to The State of São Paulo Research Foundation (FAPESP) for the financial grants.

COPYRIGHT

© CEVAP 2011

SUBMISSION STATUS

Received: March 21, 2011.

Accepted: June 28, 2011.

Abstract published online: June 30, 2011.

Full paper published online: November 31, 2011.

CONFLICTS OF INTEREST

There is no conflict.

FINANCIAL SOURCE

FAPESP (process number 2009/09569-0) provided the financial grants.

CORRESPONDENCE TO

MARIANA FÁVERO BONESSO, Departamento de Microbiologia e Imunologia, Instituto de Biociências, UNESP, Rubião Júnior, Botucatu, SP, 18618-970, Caixa Postal 510, Brasil. Phone: +55 14 3811 6058. Email: mfbonesso@hotmail.com.