臨床無菌部位金黃色葡萄球菌表現型和基因型之相關性

The Correlation Between Phenotype and Genotype of Clinical Staphylococcus aureus Strains in Sterile Sites.

張皓奇(Chi-Hao Chang)

指導教授 ： 曹世明

中山醫學大學/醫學院/生化微生物免疫研究所/碩士(2018年)

摘要

金黃色葡萄球菌(Staphylococcus aureus）為革蘭氏陽性球菌，是常存在於皮膚及黏膜呼吸道。造成皮膚軟組織感染、菌血症、肺炎等疾病 具有較高的死亡率和併發症。抗甲氧西林金黃色葡萄球菌（Methicillin-resistant Staphylococcus aureus）簡稱為MRSA，被稱為「超級細菌」。其依據表現型和基因型的差異而分成兩種，一為院內感染型MRSA(Hospital-acquired MRSA，HA-MRSA)和社區感染型MRSA(Community-acquired MRSA，CA-MRSA)。這兩種分型主要是在基因表現型上有不同差異。
本次研究目的則是分析探討近一年由無菌部位檢體分離出MRSA菌株的表現型 (phenotypic) 與基因型 (genotypic) 之差異，找出MIC、Phenotype與Genotype之間的關係。
材料方法為2016年四月到2017年八月間於中山醫學大學附設醫院之臨床微生物實驗室收集之127株之臨床無菌部位來源的金黃色葡萄球菌，根據CLSI瓊脂稀釋法(agar dilution method)來偵測Cefoxitin和Oxacillin的最低抑菌濃度(Minimal inhibition concentration，MIC)，以及使用Multiplex-Polymerase chain reaction (M-PCR)來測定MRSA之基因盒(SCCmec)中mec基因複合體(mec gene complex)和ccr基因複合體(ccr gene complex)類型。
實驗結果發現Phoenix的檢測穩定。在Genotype中則是有些為落差及重要發現。但是不論手動或是儀器自動檢測皆會有漏網之魚，所以Genotype的分子生物檢驗仍占有其重要性，由此可見多方式檢測之重要性。
MRSA基因隨環境演變，導致Phenotype及Genotype的多樣性，臨床上必須每年監測菌種的改變及進行基因進一步研究，以符合臨床治療上的需求。

關鍵字

抗甲氧西林金黃色葡萄球菌 ； 最低抑菌濃度

並列摘要

Staphylococcus aureus is gram-positive cocci, frequently found in the nose, respiratory tract, and on the skin. Causes skin and soft tissue infection, bacteremia, pneumonia and other diseases with high mortality and complications., Methicillin-resistant Staphylococcus aureus is referred to as MRSA, and as known as “super bacteria” in common. MRSA is divided into two types according to the difference in phenotype ad genotype. The one acquired in hospital called “Hospital-acquired MRSA” (HA-MRSA), the other acquired in community called “Community-acquired MRSA” (CA-MRSA). They are mainly different in genotype.
The purpose of studyaim to analyze the difference between phenotype and genotype of the MRSA isolated from the sterile sites.
A total of 127 strains of MRSAwas collected and tested the antimicrobial susceptibilities for vancomycin, cefoxitin, and oxacillin by using agar dilution according to the guideline of Clinical Laboratory Standard Institute (CLSI). Phenotypes were detected by a minimum inhibitory concentration (MIC). Then, the genotype of the MRSA strain was detected by polymerase chain reaction (PCR).
Results found that the detection of Phoenix is trusted . In genotype, there are some gaps and important findings. Whether manual or automatic detection of the instrument, there will be mistake.
The gene of MRSA evolves with the environment, leading to the diversity of phenotype and geneotype. It is necessary to monitor changes of strains and carry out further research on genes in order to fit needs of clinical treatment.

並列關鍵字

MRSA ； MIC ； Cefoxitin ； Oxacillin ； M-PCR

參考文獻

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