Nouwen J L, van Belkum A, de Marie S, Sluijs J, Wielenga J J, Kluytmans J A, Verbrugh H A
Department of Medical Microbiology & Infectious Diseases, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands.
J Clin Microbiol. 1998 Sep;36(9):2696-702. doi: 10.1128/JCM.36.9.2696-2702.1998.
The detailed analysis of 411 strains of coagulase-negative staphylococci (CoNS) obtained from 40 neutropenic hemato-oncologic patients (61 Hickman catheter episodes) on intensive chemotherapy is described. By random amplification of polymorphic DNA (RAPD) analysis, a total of 88 different genotypes were detected: 51 in air samples and 30 in skin cultures prior to insertion, 12 in blood cultures after insertion, and only 5 involved in catheter-related infections (CRI). Two RAPD genotypes of Staphylococcus epidermidis predominated, and their prevalence increased during patient hospitalization. At insertion, these clones constituted 11 of 86 (13%) CoNS isolated from air samples and 33 of 75 (44%) CoNS isolated from skin cultures. After insertion, their combined prevalence increased to 33 of 62 (53%) in catheters not associated with CRI and 139 of 188 (74%) in catheters associated with CRI (P = 0.0041). These two predominant S. epidermidis clones gave rise to a very high incidence of CRI (6.0 per 1,000 catheter days) and a very high catheter removal rate for CRI, 70%, despite prompt treatment with vancomycin. A likely source of S. epidermidis strains involved in CRI appeared to be the skin flora in 75% of cases. The validity of these observations was confirmed by pulsed-field gel electrophoresis (PFGE) of SmaI DNA macrorestriction fragments of blood culture CoNS isolates. Again, two predominant CoNS genotypes were found (combined prevalence, 60%). RAPD and PFGE yielded concordant results in 75% of cases. Retrospectively, the same two predominant CoNS clones were also found among blood culture CoNS isolates from the same hematology department in the period 1991 to 1993 (combined prevalence, 42%) but not in the period 1978 to 1982. These observations underscore the pathogenic potential of clonal CoNS types that have successfully and persistently colonized patients in this hemato-oncology department.
本文描述了对40例接受强化化疗的中性粒细胞减少血液肿瘤患者（61次希克曼导管置入事件）所获得的411株凝固酶阴性葡萄球菌（CoNS）进行的详细分析。通过随机扩增多态性DNA（RAPD）分析，共检测到88种不同基因型：置入前空气样本中有51种，皮肤培养物中有30种，置入后血培养中有12种，只有5种与导管相关感染（CRI）有关。表皮葡萄球菌的两种RAPD基因型占主导地位，且在患者住院期间其流行率增加。置入时，这些克隆在从空气样本分离的86株CoNS中占11株（13%），在从皮肤培养物分离的75株CoNS中占33株（44%）。置入后，在与CRI无关的导管中，它们的合并流行率增至62株中的33株（53%），在与CRI相关的导管中增至188株中的139株（74%）（P = 0.0041）。这两种主要的表皮葡萄球菌克隆导致CRI的发生率非常高（每1000导管日6.0例），且CRI的导管拔除率非常高，达70%，尽管已及时用万古霉素治疗。在75%的病例中，参与CRI的表皮葡萄球菌菌株的可能来源似乎是皮肤菌群。通过对血培养CoNS分离株的SmaI DNA大限制性片段进行脉冲场凝胶电泳（PFGE），证实了这些观察结果的有效性。同样，发现了两种主要的CoNS基因型（合并流行率为60%）。在75%的病例中，RAPD和PFGE产生了一致的结果。回顾性研究发现，在1991年至1993年期间，同一血液科的血培养CoNS分离株中也存在相同的两种主要CoNS克隆（合并流行率为42%），但在1978年至1982年期间未发现。这些观察结果强调了在该血液肿瘤科室中成功且持续定植于患者的克隆性CoNS类型的致病潜力。
