Struelens M J, Schwam V, Deplano A, Baran D
Unité d'Epidémiologie, Hôpital Erasme, Brussels, Belgium.
J Clin Microbiol. 1993 Sep;31(9):2320-6. doi: 10.1128/jcm.31.9.2320-2326.1993.
Genome macrorestriction fingerprinting with XbaI and DraI was used to analyze the relatedness of 166 Pseudomonas aeruginosa isolates collected from 31 cystic fibrosis patients over a 1- to 20-month period and to correlate their genotype with patterns of resistance to 14 antimicrobial agents. Quantitative comparison of intra- and interpatient similarities of P. aeruginosa macrorestriction patterns disclosed two discrete ranges that clearly discriminated subclonal variation (> 80% relatedness) and clonal diversity (10 to 70% relatedness). Cloning-derived mutants exhibited up to 20% divergence of genomic macrorestriction patterns during the course of chronic colonization of individual patients. Change of susceptibility to multiple antimicrobial agents developed in 50% of sequential pairs of isolates from individual patients. Only 19% of these susceptibility changes were attributable to strain substitution, while the majority (56%) of resistance changes were associated with minor genomic variations of a persistent strain. Sixty-six percent of patients harbored one strain, and 33% carried two strains. Three common strains colonized 5 (28%) of 18 patients attending a cystic fibrosis clinic, and another two strains colonized two patient pairs (31%) of 13 patients staying at a rehabilitation center, suggesting potential cross-infection in these settings. By indexing regional polymorphisms throughout the chromosome structure, macrorestriction analysis can monitor subclonal evolution of P. aeruginosa and identify isogenic resistance mutants. Quantitative macrorestriction fingerprinting enables discrimination between clonal variants and clones of distinct origins and should therefore provide a reliable tool for investigating the mode of acquisition of P. aeruginosa in cystic fibrosis patients.
利用XbaI和DraI进行基因组宏观限制性指纹分析，以分析在1至20个月期间从31名囊性纤维化患者中收集的166株铜绿假单胞菌分离株的相关性，并将其基因型与对14种抗菌药物的耐药模式相关联。对铜绿假单胞菌宏观限制性图谱的患者内和患者间相似性进行定量比较，发现了两个离散范围，可清楚地区分亚克隆变异（相关性>80%）和克隆多样性（相关性10%至70%）。在个体患者的慢性定植过程中，克隆衍生的突变体表现出高达20%的基因组宏观限制性图谱差异。在个体患者连续分离的菌株对中，50%出现了对多种抗菌药物敏感性的变化。这些敏感性变化中只有19%可归因于菌株替代，而大多数（56%）耐药性变化与持续存在菌株的微小基因组变异有关。66%的患者携带一种菌株，33%携带两种菌株。三种常见菌株定植于一家囊性纤维化诊所的18名患者中的5名（28%），另外两种菌株定植于一家康复中心的13名患者中的两对患者（31%），提示在这些环境中可能存在交叉感染。通过对整个染色体结构的区域多态性进行索引，宏观限制性分析可以监测铜绿假单胞菌的亚克隆进化并鉴定同基因耐药突变体。定量宏观限制性指纹分析能够区分不同起源的克隆变体和克隆，因此应该为研究囊性纤维化患者中铜绿假单胞菌的获得方式提供一个可靠的工具。
