National Food Institute, DTU, Division of Microbiology and Risk Assessment, Bülowsvej 27, DK-1790 Copenhagen V, Denmark.
J Microbiol Methods. 2010 Jan;80(1):25-43. doi: 10.1016/j.mimet.2009.10.012. Epub 2009 Oct 29.
A classification system for plasmids isolated from enterococci and other Gram-positive bacteria was developed based on 111 published plasmid sequences from enterococci and other Gram-positive bacteria; mostly staphylococci. Based on PCR amplification of conserved areas of the replication initiating genes (rep), alignment of these sequences and using a cutoff value of 80% identity on both protein and DNA level, 19 replicon families (rep-families) were defined together with several unique sequences. The prevalence of these rep-families was tested on 79 enterococcal isolates from a collection of isolates of animal and human origin. Difference in prevalence of the designed rep-families were detected with rep(9) being most prevalent in Enterococcus faecalis and rep(2) in Enterococcus faecium. In 33% of the tested E. faecium and 32% of the tested E. faecalis no positive amplicons were detected. Furthermore, conjugation experiments were performed obtaining 30 transconjugants when selecting for antimicrobial resistance. Among them 19 gave no positive amplicons indicating presence of rep-families not tested for in this experimental setup.
基于 111 株肠球菌和其他革兰氏阳性菌（主要为葡萄球菌属）质粒的已发表序列，建立了一个可用于分离这些菌的质粒的分类系统。根据复制起始基因（rep）保守区的 PCR 扩增、这些序列的比对，以及在蛋白质和 DNA 水平上均设定 80%同一性的截断值，共定义了 19 种复制子家族（rep 家族）和一些独特的序列。在一个包含动物和人类来源的分离株的收集物中，对 79 株肠球菌分离株进行了这些 rep 家族的流行率检测。在所设计的 rep 家族中，rep(9)在粪肠球菌中最为流行，rep(2)在屎肠球菌中最为流行。在 33%的测试粪肠球菌和 32%的测试屎肠球菌中，未检测到阳性扩增子。此外，还进行了接合实验，当选择抗微生物药物耐药性时，获得了 30 个转导子。其中 19 个没有阳性扩增子，这表明存在本实验方案中未测试的 rep 家族。
