Molecular determination of carriage of the mecA locus in coagulase negative staphylococci in screening swabs from patients in an intensive care unit.

Staphylococci are important nosocomial pathogens, which are easily transmitted from patient to patient, and there is concern over the recent emergence of antibiotic resistance to the β lactam class of antimicrobial drugs, particularly within methicillin resistant Staphylococcus aureus (MRSA). Coagulase negative staphylococci, although relatively less pathogenic than S aureus, are important pathogens, particularly in immunocompromised or immunosuppressed patients, where they can cause line associated bacteraemia and infections of prosthetic devices, such as heart valves. Recently, several studies have suggested that S aureus may acquire the mecA locus through the horizontal gene transfer of this locus from methicillin resistant (mecA +ve) coagulase negative staphylococci to methicillin sensitive S aureus , thus resulting in the emergence of MRSA phenotypes.1,2 Therefore, the aim of our study was to determine the incidence of carriage of the mecA locus in coagulase negative staphylococci isolated from screening swabs from an intensive care unit (ICU) in a large acute teaching hospital. Seventy five patients within the ICU at Belfast City Hospital …