Investigation of nasal methicillin-resistant staphylococcus aureus (MRSA) carriage in healthcare workers

Staphylococci are important infectious agents that have been known for more than 100 years. S. aureus is the most frequently isolated species as a human pathogen among Staphylococcus genus. It causes both community and hospital acquired infections with significant morbidity and mortalityMRSA is a different strain of S.aureus that is resistant to all penicillins including penicillinase-resistant penicillins and cephalosporins, as well as a lot of antibiotics such as clindamycin, erythromycin, tetracycline, and aminoglycosides. Treatment options for MRSA infections are very limited. MRSA infections generally occur via transmission of bacteria from carriers.MRSA, unlike sensitive S.aureus, harbors a resistance island named SCCmec (staphylococcal casette chromosome mec) and a resistance gene mecA inside. SCCmec is divided into types according to mec and ccr gene complexes and into subtypes according to the differences in the J regions. Athough 8 types were defined recently, most of the MRSA strains have one of the five SCCmec types (SCCmec types I, II, III, IV, V). They show differences from each other in terms of genetic content and size. Majority of hospital-acquired MRSA clones (HA-MRSA) carry the SCCmec type I, II or III while most of the community-acquired (CA-MRSA) strains have SCCmec IV.Important data are provided with typing of MRSA strains for investigation of outbreaks, prevention nosocomial diseases and taking of preventive measures for control of infections.In this study, investigation the nasal carriage of MRSA among Karadeniz Technical University (KTU) Farabi Hospital workers is aimed. MRSA strains were identified among S.aureus isolates from nasal swab samples from a total of 414 health care workers in different age groups and working in different units. SCCmec types of these strains were determined by polymerase chain reaction method.S. aureus strains were isolated from 34 (8.2%) of 414 health care workers. S.aureus, carriage rates were 9.9% (10/101) among physicians, 6.2% (11/176) for nurses, and 9.4% (13/137) for auxiliary health workers. Eleven strains were identified as MRSA. Rates of nasal MRSA carriage were found as 2.9% for physicians, 2.2% nurses, 2.9% auxiliary health workers, and 2.6% totally. Seven of the 11 MRSA strains (63.6%) were type IV as the other four (36.3%) strains remained untypable.As a result, it was found that health care workers carried MRSA clones mostly SCCmec type IV that was mainly associated community-acquired MRSA clones and didn?t contain multidrug-resistance elements.Key words: Health care workers, MRSA, SCCmec types