Al-Thawadi Sahar I, Kessie George, Dela Cruz Damian, Al-Ahdal Mohammed N
Department of Biological and Medical Research, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia.
Saudi Med J. 2003 Dec;24(12):1317-24.
To evaluate and compare 3 widely used molecular techniques, namely, restriction endonuclease analysis of plasmid deoxyribonucleic acid (REAP), randomly amplified polymorphic DNA (RAPD) and pulsed-field gel electrophoresis (PFGE) for their suitability and usefulness in the typing and fingerprinting of bacterial isolates.
Twenty-four epidemiologically unrelated methicillin-resistant Staphylococcus aureus (MRSA) isolates were used to evaluate the molecular typing methods (REAP, RAPD and PFGE). The study was conducted at the Research and Diagnostic Laboratories of King Faisal Specialist Hospital and Research Center from January 2002 through January 2003.
Only 20.8% of all isolates studied were of the same genotypes by all 3 methods. Two major clusters of strains each representing 33% of the total number of isolates were identified by REAP analysis. Each of RAPD and PFGE however, identified one major cluster represented by 54% and 83% of the total number of isolates, all 3 typing methods, therefore, showed the clonal genetic relatedness among distant MRSA isolates. However inter-strain comparison of fingerprint data generated from each method revealed differences in clonal representation of the MRSA isolates.
Although a variety of molecular assays are available for typing of bacterial species, there is no single standardized protocol for routine analysis. Reproducibility and interpretation of genotypic data are therefore, highly dependent on methodologies employed by the individual laboratory. Our findings illustrate the importance of using a combination of methods in typing schemes of bacterial isolates. In terms of reproducibility and typeability we found that PFGE is superior to REAP and RAPD and, therefore, more suitable for routine, standardized tracing of nosocomial bacterial isolates.
评估并比较三种广泛使用的分子技术，即质粒脱氧核糖核酸限制性内切酶分析（REAP）、随机扩增多态性DNA（RAPD）和脉冲场凝胶电泳（PFGE）在细菌分离株分型和指纹图谱分析中的适用性和实用性。
使用24株流行病学上无关的耐甲氧西林金黄色葡萄球菌（MRSA）分离株来评估分子分型方法（REAP、RAPD和PFGE）。该研究于2002年1月至2003年1月在法赫德国王专科医院和研究中心的研究与诊断实验室进行。
在所有研究的分离株中，只有20.8%通过所有三种方法具有相同的基因型。REAP分析确定了两个主要菌株簇，每个簇占分离株总数的33%。然而，RAPD和PFGE各自确定了一个主要簇，分别占分离株总数的54%和83%。因此，所有三种分型方法都显示了远距离MRSA分离株之间的克隆遗传相关性。然而，对每种方法产生的指纹数据进行菌株间比较发现，MRSA分离株的克隆表现存在差异。
虽然有多种分子检测方法可用于细菌物种分型，但尚无单一的标准化常规分析方案。因此，基因型数据的可重复性和解释高度依赖于各个实验室采用的方法。我们的研究结果说明了在细菌分离株分型方案中使用多种方法的重要性。在可重复性和分型能力方面，我们发现PFGE优于REAP和RAPD，因此更适合用于医院细菌分离株的常规标准化追踪。
