静脉药物使用者感染性心内膜炎的临床和分子流行病学。

Clinical and molecular epidemiology of infective endocarditis in intravenous drug users.

机构信息

Department of Internal Medicine, Pingtung Christian Hospital, Pingtung, Taiwan, R.O.C.

出版信息

J Chin Med Assoc. 2009 Dec;72(12):629-33. doi: 10.1016/S1726-4901(09)70444-7.

DOI:10.1016/S1726-4901(09)70444-7

PMID:20028642

Abstract

BACKGROUND

Infective endocarditis (IE) in intravenous drug users has been increasing in incidence. The major pathogen used to be methicillin-susceptible Staphylococcus aureus, but resistant isolates have also been increasing. This study aimed to investigate the clinical characteristics of IE in intravenous drug users and to evaluate the molecular patterns of methicillin-resistant S. aureus (MRSA) that cause IE in these drug users.

METHODS

A total of 37 episodes of IE in intravenous drug users hospitalized from 1980 to 2006 at a 1,250-bed teaching hospital in Southern Taiwan were evaluated retrospectively. The genetic relatedness of S. aureus strains was assessed using pulsed-field gel electrophoresis. Polymerase chain reaction was used to detect Panton-Valentine leukocidin (PVL) and staphylococcal gamma-hemolysin (Hlg), and to determine the staphylococcal chromosomal cassette carrying the mecA methicillin-resistant gene (SCCmec) type.

RESULTS

The patients had a mean +/- standard deviation age of 31.5 +/- 9.25 years, with a male predominance of 76%. Hepatitis C was present in all patients. Methicillin-susceptible S. aureus accounted for 76% of infections, and the most common clinical symptoms were fever (97%) and embolic phenomenon (68%). There were 4 MRSA isolates, 3 of which were SCCmec type III. PVL and Hlg genes were found in 2 and 3 MRSA isolates, respectively. Eighty percent similarity was found among the MRSA isolates by pulsed-field gel electrophoresis.

CONCLUSION

Our results suggest that coinfection with hepatitis C was common in intravenous drug users with IE, and that molecular patterns of MRSA isolates had high similarity. SCCmec type III, which is usually hospital-acquired, could have caused the community-associated MRSA endocarditis in our patients.

摘要

背景

静脉注射毒品使用者的感染性心内膜炎（IE）发病率不断上升。主要病原体曾经是耐甲氧西林金黄色葡萄球菌，但耐药分离株的数量也在增加。本研究旨在调查静脉注射毒品使用者中 IE 的临床特征，并评估引起这些吸毒者 IE 的耐甲氧西林金黄色葡萄球菌（MRSA）的分子模式。

方法

回顾性评估了 1980 年至 2006 年期间在台湾南部一家拥有 1250 张床位的教学医院住院的 37 例静脉注射毒品使用者的 IE 病例。使用脉冲场凝胶电泳评估金黄色葡萄球菌菌株的遗传相关性。聚合酶链反应用于检测杀白细胞素（PVL）和葡萄球菌γ-溶血素（Hlg），并确定携带 mecA 耐甲氧西林基因（SCCmec）的葡萄球菌染色体盒（SCCmec）类型。

结果

患者的平均年龄为 31.5 ± 9.25 岁，男性占 76%。所有患者均患有丙型肝炎。耐甲氧西林金黄色葡萄球菌占感染的 76%，最常见的临床症状是发热（97%）和栓塞现象（68%）。有 4 株 MRSA 分离株，其中 3 株属于 SCCmec 型 III。2 株和 3 株 MRSA 分离株分别发现了 PVL 和 Hlg 基因。MRSA 分离株通过脉冲场凝胶电泳发现 80%的相似度。