Detection of Methicillin-resistant Staphylococcs aureus from the Anterior Nares of Healthcare Workers in a Intensive Care Unit by Using PBP2a Rapid Kit and Direct Coagulase Test

중환자실에 근무하는 의료인의 전비강에서 PBP2a Rapid Kit와 직접 Coagulase 검사를 이용한 Methicillin-resistant Staphylococcus aureus의 검출

We evaluated the performance of a novel screening test, PBP2a MRSA rapid kit (Dinona Inc., Iksan, Korea), for methicillin-resistant Staphylococcus aureus (MRSA) based on a immunochromatographic assay. The test is able to detect penicillin-binding protein 2a (PBP2a) using the nasal specimens from health care workers. The nasal specimens were obtained from 69 healthcare workers and were incubated in enrichment broth followed eight hours incubatin in BHI with cefoxitin $4{\mu}g/mL$. These broth were tested by PBP2a Rapid Kit. The enrichment broths were also directly tested for tube coagulase using the conventional identification method. 19 of 22 MRSA showed positive results by PBP2a rapid test and direct coagulase test (the sensitivity for detection of MRSA, 86.36%). While, 8 of 47 non-MRSA showed false positive results for the two tests. All of the 8 non-MRSA which showed false positive were co-colonizing isolates with MRCNS and MSSA. In addition, 46 of 49 methicillin-resistant staphylococci (MRS) showed positive results for PBP2a MRSA rapid kit (the sensitivity for detection of MRS, 93.8%), and all of 20 non-MRS showed negative results (specificity, 100%). The combination of PBP2a MRSA rapid kit and direct coagulase test showed the good sensitivity for detection of MRSA from anterior nares but frequently showed false positive results from the co-colonizing carrier with MRCNS and MSSA.