MRSA

MRSA, (from methicillin-resistant Staphylococcus aureus), is the name for the strains of bacteria Staphylococcus aureus, who have acquired resistance to antibiotic methicillin. Responsible for resistance is gene mecA located on the staphylococcal chromosome cassette mec (SCCmec), which encodes the enzyme PBP2a (abbreviated penicillin-binding protein). This enzyme acts as a transpeptidase (ie it is involved in the synthesis of the bacterial cell wall peptidoglycan), but is not inhibited by methicillin and other penicillin antibiotics. Methicillin is used worldwide for treatment of S. aureus, similar to oxacillin used in the Czech Republic. These strains have spread especially in hospitals due to the use of broad-spectrum antibiotics that exert selection pressure on bacteria. MRSA has usually become resistant to a number of other antibiotics, and intravenous vancomycin must be used for treatment.

In 2002 appeared strains of VRSA (from vancomycin-resistant S. aureus) resistant even to vancomycin. Two reported strains in the United States have been shown to be susceptible to quinupristin-dalfopristin, linezolid and TMP-SMX (Trimethoprim-sulfamethoxazole = cotrimoxazole), but were resistant to tetracycline.

The patient with MRSA must be isolated in a specially designed room and very strict hygiene rules must be followed to prevent further spread of the dangerous strain.

Related articles

 * Staphylococcus aureus
 * Stafylokokové infekce

Literature

 * GLADWIN, Mark a William TRATTLER. Clinical Microbiology Made Ridiculously Simple. 3. vydání. MedMaster Inc. 2004. ISBN 1935660039.
 * VOTAVA, Miroslav, et al. Lékařská mikrobiologie speciální. 1. vydání. Brno : Neptun, 2003. 495 s. ISBN 80-902896-6-5.