(methicillin) n. a semisynthetic penicillin that was originally used to treat infections by penicillin-resistant staphylococci. It has been superseded for this purpose by *flucloxacillin but continues to be used to test the drug sensitivity of staphylococci. Meticillin-resistant staphylococci (MRS) can be responsible for increasing rates of infection in hospitals. Until recently, such infections have responded to *vancomycin, but strains of bacilli have emerged that are resistant to vancomycin, giving rise to infections that are very difficult to treat. See also superinfection.
meticillin- (or multiple-) resistant Staphylococcus aureus: an increasingly common dangerous bacterium that is resistant to many antibiotics. It is responsible for many infections in already ill people in hospitals and is now also seen more widely in the general community (community-associated MRSA; CA-MSRA), usually in the form of skin infections. See meticillin.... mrsa
n. an infection arising during the course of another infection and caused by a different microorganism, which is usually resistant to the drugs used to treat the primary infection. The infective agent may be a normally harmless inhabitant of the body that becomes pathogenic when other harmless types are removed by the drugs or it may be a resistant variety of the primary infective agent, such as *MRSA (see also meticillin).... superinfection
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