Resistance to methicillin in isolates of Staphylococcus aureus from blood and cerebrospinal fluid in Wales, 1993-1997.

Surveillance data for organisms isolated from blood cultures and cerebrospinal fluid (CSF) specimens has been gathered electronically in Wales since 1993. Over this period the proportion of total reported organisms from blood cultures and CSF represented by methicillin-resistant staphylococci (MRSA) has risen steadily. This has corresponded to a rise in rates of methicillin resistance amongst Staphylococcus aureus isolated from blood cultures and CSF from 4 to 43%. In certain age/gender groups in 1997, more than 50% of isolates of S. aureus were resistant to methicillin, suggesting that a change in empirical treatment may be necessary for suspected staphylococcal sepsis.