Dynamics of hemodialysis catheter colonization by coagulase-negative staphylococci
Dynamics of hemodialysis catheter colonization by coagulase-negative staphylococci
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DOI：
10.1086/502586
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发表时间：
2005-06-01
影响因子：
4.5
通讯作者：
Mühlemann, K
中科院分区：
文献类型：
--
作者：
Fux, CA;Uehlinger, D;Mühlemann, K
目的：导管定植是导管相关感染发病机制中必要但缺乏特征的步骤。研究了中心静脉血液透析导管的定植动态，重点研究了凝固酶阴性葡萄球菌（con）及其群体遗传学、抗生素耐药性和生物膜形成。对con菌落形态的均匀性进行了评价。设计：前瞻性、纵向研究，为期1158个导管日，对皮肤拭子、每周导管血液和导管刷取样以及导管尖端进行微生物分析。单位：某大学医院血液透析科。患者：26例，非隧道导管24根，隧道导管5根。结果：19根（65.5%）导管被定植，17根被con定植，17.2%的导管内腔被con定植，3周后首次检测到。44.8%的导管外表面在至少2周内发生定植。53个克隆的PFGE鉴定出10个克隆和20个独特的分离株。与独特的分离株相比，克隆分离株在导管血和刷培养中出现的频率更高（41%比15%），对更多抗生素耐药（中位数，7比2），并且更容易携带icaA基因（64.1%比40%）。4根（23.5%）导管显示基于PFGE的con混合物定殖。从插入导管到这种混合CoNS定植的时间比仅使用一种CoNS PFGE定植的时间更长（42天vs 25天）。结论：血液透析导管的定植以多药耐药、icaa阳性的CoNS克隆为主。混合con定殖发生，但延迟，提示顺序重复感染的过程。
OBJECTIVES: Catheter colonization is a necessary but poorly characterized step in the pathogenesis of catheter-related infections. Colonization dynamics of central venous hemodialysis catheters were studied with emphasis on coagulase-negative staphylococci (CoNS) and their population genetics, antibiotic resistance, and biofilm formation. The homogeneity of CoNS colony morphotypes was evaluated.DESIGN: Prospective, longitudinal study during 1,158 catheter-days with microbiological analysis of skin swabs, weekly catheter blood and brush samples, and catheter tips.SETTING: Hemodialysis unit of a university hospital.PATIENTS: Twenty-six patients with 24 non-tunneled and 5 tunneled catheters.,RESULTS: Nineteen (65.5%) of the catheters became colonized, 17 by CoNS. CoNS colonization of the inner lumen was observed in 17.2% of the catheters and was first detectable after 3 weeks. Colonization of the outer surface occurred in 44.8% of the catheters within a minimum of 2 weeks. PFGE of 53 CoNS revealed 10 clones and 20 unique isolates. Isolates from clones were more frequent in catheter blood and brush cultures than were unique isolates (41% vs 15%), were resistant to more antibiotics (median, 7 vs 2), and tended to more often carry the icaA gene (64.1% vs 40%). Four (23.5%) of the catheters showed colonization with a mixture of CoNS based on PFGE. The time from catheter insertion to such mixed CoNS colonization was longer than that for colonization with one CoNS PFGE pattern only (42 vs 25 days).CONCLUSIONS: Colonization of hemodialysis catheters is dominated by multidrug-resistant, icaA-positive CoNS clones. Mixed CoNS colonization occurs, but is delayed, suggesting a process of sequential superinfection.