Casey A L, Worthington T, Caddick J M, Hilton A C, Lambert P A, Elliott T S J
Department of Clinical Microbiology and Infection Control, The Queen Elizabeth Hospital, University Hospital Birmingham NHS Foundation Trust, Edgbaston, Birmingham B15 2TH, UK.
J Infect. 2006 Apr;52(4):282-9. doi: 10.1016/j.jinf.2005.06.005. Epub 2005 Jul 19.
A rapid random amplification of polymorphic DNA (RAPD) technique was developed to distinguish between strains of coagulase-negative staphylococci (CoNS) involved in central venous catheter (CVC)-related bloodstream infection. Its performance was compared with that of pulsed-field gel electrophoresis (PFGE).
Patients at the University Hospital Birmingham NHS Foundation Trust, U.K. who underwent stem cell transplantation and were diagnosed with CVC-related bloodstream infection due to CoNS whilst on the bone marrow transplant unit were studied. Isolates of CoNS were genotyped by PFGE and RAPD, the latter employing a single primer and a simple DNA extraction method.
Both RAPD and PFGE were highly discriminatory (Simpson's diversity index, 0.96 and 0.99, respectively). Within the 49 isolates obtained from blood cultures of 33 patients, 20 distinct strains were identified by PFGE and 25 by RAPD. Of the 25 strains identified by RAPD, nine clusters of CoNS contained isolates from multiple patients, suggesting limited nosocomial spread. However, there was no significant association between time of inpatient stay and infection due to any particular strain.
The RAPD technique presented allows CoNS strains to be genotyped with high discrimination within 4h, facilitating real-time epidemiological investigations. In this study, no single strain of CoNS was associated with a significant number of CVC-related bloodstream infections.
开发一种快速随机扩增多态性DNA（RAPD）技术，以区分与中心静脉导管（CVC）相关血流感染有关的凝固酶阴性葡萄球菌（CoNS）菌株。并将其性能与脉冲场凝胶电泳（PFGE）进行比较。
对英国伯明翰大学医院国民保健服务信托基金会接受干细胞移植且在骨髓移植科期间因CoNS被诊断为CVC相关血流感染的患者进行研究。采用PFGE和RAPD对CoNS分离株进行基因分型，后者采用单一引物和简单的DNA提取方法。
RAPD和PFGE都具有高度的鉴别力（辛普森多样性指数分别为0.96和0.99）。在从33例患者的血培养中获得的49株分离株中，PFGE鉴定出20种不同菌株，RAPD鉴定出25种。在RAPD鉴定出的25种菌株中，9个CoNS簇包含来自多名患者的分离株，提示医院内传播有限。然而，住院时间与任何特定菌株引起的感染之间没有显著关联。
所介绍的RAPD技术可在4小时内对CoNS菌株进行高分辨率基因分型，便于进行实时流行病学调查。在本研究中，没有单一的CoNS菌株与大量CVC相关血流感染相关。
