Korean Journal of Microbiology (미생물학회지)

The Microbiological Society of Korea (한국미생물학회)
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Comparison Between Antimicrobial Susceptibility Test and mecA PCR Method for Reading of Methicillin-Resistant Staphylococcus aureus

메티실린 내성 황색포도알균 판독에 있어 항균제 감수성 검사와 mecA PCR법의 비교

  • Kim, Su-Jung (Department of Clinical Pathology, Daegu Health College)
  • 김수정 (대구보건대학교 임상병리과)
  • Received : 2011.11.18
  • Accepted : 2011.12.20
  • Published : 2011.12.31
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Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) is one of major pathogen causing hospital infection and several diseases such as purulent infection, bacteremia. The isolation ratio of MRSA is gradually increased up to 80% in the hospital, which makes a limitation for treatment of antibiotics because the isolated MRSA show resistance to methicillin as well as other antibiotics. This study proposes that mecA detecting methods which are not commonly used because of cost in the hospital is a more accurate method than Susceptibility Testing to detect a MRSA. We compared Staphylococcus aureus ATCC 29213 as a negative control and 20 MRSA strains isolated from patients by these two methods. We amplified mecA gene by polymerase chain reaction (PCR) and confirmed the PCR products by sequencing. All of the MRSA showed oxacillin and cefoxitin resistance whereas 85% (16/19) of the strains had mecA wildtype. These results suggest that some of the MRSA are mecA mutants therefore mecA genotyping reinforces the MRSA detection by antibiotic susceptibility test.

Methicillin-resistant Staphylococcus aureus (MRSA)는 화농성 질환, 균혈증을 유발하고 병원내 감염의 주요 원인균으로 알려져 있다. 병원에서의 MRSA 분리율은 점차 증가하여 80% 이상으로 보고 되고 있으며 Methicillin 뿐만 아니라 다른 항균제에도 내성을 나타냄으로 치료를 위한 항균제 사용에 제한을 받고 있다. 이에 본 연구에서는 MRSA의 정확한 판정을 통해 항생제 남용을 막고자 대부분의 병원에서 사용하는 항균제 감수성 검사법과 경제적인 면으로 인해 병원내에서 많이 사용되고 있지 않지만 정확도가 높은 mecA 유전자 검출법을 서로 비교하였다. 그 결과 대조군인 Methicillin-susceptible Staphylococcus aureus와 실험군 MRSA 20 균주를 대상으로 항균제 감수성 검사법과 mecA 유전자 PCR 검출법을 실시한 결과 MRSA 20 균주는 Oxacillin과 Cefoxitin에 모두 내성을 나타냈으나 mecA 유전자 검출에서는 20 개 중 17 개에서만 유전자가 검출되어 염기서열분석 결과 mecA 유전자임을 확인하였다. 이런 결과로 보아 mecA(-) 3 균주는 mecA 유전자의 변이로 추측할 수 있기에 임상에서의 MRSA의 판정은 항균제 디스크법과 mecA 유전자 PCR 검출법을 동시에 사용함으로 정확한 MRSA 진단에 도움을 주고자 한다.

Keywords

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