臺灣侵襲性methicillin抗藥金黃色葡萄球菌對vancomycin感受性的趨勢與分生特性研究

中山醫學大學機構典藏 CSMUIR > 醫學院 > 醫學研究所 > 博碩士論文 > Item 310902500/12315

Please use this identifier to cite or link to this item: https://ir.csmu.edu.tw:8080/ir/handle/310902500/12315

Title:	臺灣侵襲性methicillin抗藥金黃色葡萄球菌對vancomycin感受性的趨勢與分生特性研究 Trend in vancomycin susceptibility and correlation with molecular characteristics of methicillin-resistant Staphylococcus aureus causing invasive infections in Taiwan
Authors:	曹世明 Tsao, Shih-Ming
Contributors:	中山醫學大學:醫學研究所;曹昌堯
Keywords:	抗甲氧苯青黴素金黃色葡萄球菌;萬古黴素 MRSA;vancomycin
Date:	2015
Issue Date:	2015-09-21T03:31:37Z (UTC)
Abstract:	研究目的：本篇論文研究目的在於探討具侵入感染性的抗甲氧苯青黴素金黃色葡萄球菌（methicillin resistant S. aureus， MRSA）對萬古黴素(vancomycin)感受性的趨勢與其分子生物學特徵。研究材料及方法：從2006年至2010年，五年期間，藉著TIST (Tigecycline in vitro Surveillance in Taiwan)計畫所收集台灣地區十五家醫學中心和區域醫院臨床菌株，MRSA共計670株。以瓊脂稀釋法 (agar dilution method)對 vancomycin最低抑菌濃度 (MIC)測量其感受性，分子生物學特徵則以多重引子聚合酶連鎖反應 (multiplex polymerase chain reaction – M-PCR) 測定增幅特定核苷酸序列 (基因)，包括；葡萄球菌攜抗藥性基因染色體卡莢 (staphylococcal cassette chromosome - SCCmec) 型別鑑定、葡萄球菌表面蛋白 (protein A) 基因多形性鑑定 (spa typing)、附屬調節基因 (accessory gene regulator gene–agr) 型別鑑定和直接重複核苷酸序列 (direct repeat unit – dru) 型別鑑定；特定菌株進行多位址序列分析 (multilocus sequence typing - MLST)。其中SCCmec types I, II, and III定義為醫院型MRSA [hospital-associated MRSA (HA-MRSA)]， SCCmec types IV, V, 和 VT則視為社區型MRSA [community-associated MRSA (CA-MRSA)]。研究結果：除一株外，所有菌株均大於或等於1 μg/mL，其中有十七株呈現vancomycin MIC of 3 μg/mL。五年研究期間，因為HA-MRSA比例減少導致MRSA對vancomycin MICs呈現下降趨勢。CA-MRSA由2006年25.6%增加到2010年46.0%。然而，代表HA-MRSA的分子生物型如SCCmec types II and III, agr groups I and II, and dru10–14的幾何平均值卻是增加的。結論：台灣地區2006-2010間不存在著萬古黴素抗藥性蔓延(Vancomycin Creep)，五年研究期間MRSA對vancomycin MICs呈現下降趨勢；趨勢形成的主要原因為CA-MRSA比例逐漸增加的影響。 Background: This study was intended to investigate the trend in vancomycin susceptibility and correlation with molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) causing invasive infections. Materials and Methods: A total of 670 MRSA isolates were collected from patients with invasive infections as part of bacterial collection in the Tigecycline in vitro Surveillance in Taiwan (TIST) from 2006 to 2010. MICs of the isolates to vancomycin were determined using the agar dilution method. Characteristics of staphylococcal cassette chromosome mec (SCCmec), mec-associated hypervariable region (dru), and accessory gene regulator (agr) of the isolates were identified by polymerase chain reaction methods. Multilocus sequence typing (MLST) executed for strains with particular molecular types. MRSA isolates with SCCmec types I, II, and III were molecularly defined as hospital-associated MRSA (HA-MRSA), and those with SCCmec types IV, V, and VT were assigned as community -associated MRSA (CA-MRSA). Results: All but 1 MRSA isolates exhibited vancomycin MICs > 1 mg/L. There were 17 strains harbored with vancomycin MICs >3 mg/L. A declining trend in vancomycin MICs among MRSA isolates was noted, which was associated with the decline in proportion of HA-MRSA. The percentage of CA-MRSA increased from25.6% in 2006 to 46.0% in 2010. An increase in the geometric mean of vancomycin MICs was found in MRSA with particular molecular types such as SCCmec types II and III, agr groups I and II, and dru10–14. Conclusions: There was no vancomycin creep among MRSA isolates, and the declining trend of vancomycin MIC against MRSA was attributed to the increasing prevalence of CA-MRSA over time.
URI:	https://ir.csmu.edu.tw:8080/ir/handle/310902500/12315
Appears in Collections:	[醫學研究所] 博碩士論文

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