Roberts Jill C, Cannons Andrew C, Amuso Philip T, Cattani Jacqueline
Center for Biological Defense, University of South Florida College of Public Health, Tampa, FL 33612, USA.
J Microbiol Methods. 2006 Aug;66(2):362-8. doi: 10.1016/j.mimet.2005.12.012. Epub 2006 Feb 17.
Pulsed-field gel electrophoresis (PFGE) is currently the gold standard for methicillin-resistant Staphylococcus aureus (MRSA) typing but only one enzyme, SmaI, is currently used for restriction digest. We report the use of virtual digestion to identify enzymes for S. aureus PFGE. Two enzymes (EagI and SacII) were identified and successfully used to characterize two sets of S. aureus isolates, 12 USA300, and 14 additional MRSA isolates comprised of seven SmaI patterns. Phylogenetic analysis of patterns generated by all enzymes determined that the USA300 MRSAs are identical. In contrast, digestion with EagI or SacII resolved one to two band differences among three MRSA pattern sets that were not detected using SmaI. These results demonstrate that a second enzyme may detect differences in S. aureus isolates not detected by single enzyme digestion. However, because isolates differing by one to two bands are considered identical, such discrimination may not be clinically or epidemiologically relevant.
脉冲场凝胶电泳（PFGE）目前是耐甲氧西林金黄色葡萄球菌（MRSA）分型的金标准，但目前仅使用一种酶SmaI进行限制性酶切。我们报告了使用虚拟酶切来鉴定用于金黄色葡萄球菌PFGE的酶。鉴定出两种酶（EagI和SacII），并成功用于对两组金黄色葡萄球菌分离株进行分型，一组为12株USA300，另一组为另外14株MRSA分离株，由七种SmaI酶切图谱组成。对所有酶产生的图谱进行系统发育分析确定，USA300 MRSA是相同的。相比之下，用EagI或SacII酶切可分辨出三种MRSA酶切图谱组之间一到两条带的差异，而使用SmaI未检测到这些差异。这些结果表明，第二种酶可能检测到单酶酶切未检测到的金黄色葡萄球菌分离株的差异。然而，由于相差一到两条带的分离株被认为是相同的，这种区分在临床或流行病学上可能不相关。
