Lund B, Billström H, Edlund C
Division of Clinical Bacteriology, Department of Laboratory Medicine, Huddinge University Hospital, Karolinska Institutet, Stockholm, Sweden.
Clin Microbiol Infect. 2006 Jun;12(6):588-91. doi: 10.1111/j.1469-0691.2006.01436.x.
This study compared the in-vitro ability of Enterococcus faecium isolates of different origin to acquire vanA by conjugation in relation to the occurrence of the esp gene. In total, 29 clinical isolates (15/29 esp+), 30 normal intestinal microflora isolates (2/30 esp+) and one probiotic strain (esp-) were studied with a filter-mating assay. Conjugation events were confirmed by PCR and pulsed-field gel electrophoresis. Among the infection-derived isolates, the esp+ isolates had higher conjugation frequencies compared with esp- isolates (p < 0.001), with a median value of 6.4 x 10(-6) transconjugants/donor. The probiotic strain was shown to acquire vanA vancomycin resistance in in-vitro filter mating experiments.
本研究比较了不同来源的屎肠球菌分离株在体外通过接合获得vanA的能力与esp基因出现情况之间的关系。总共使用滤膜交配试验研究了29株临床分离株（15/29为esp+）、30株正常肠道微生物群分离株（2/30为esp+）和1株益生菌菌株（esp-）。通过聚合酶链反应（PCR）和脉冲场凝胶电泳确认接合事件。在感染源分离株中，与esp-分离株相比，esp+分离株具有更高的接合频率（p < 0.001），转接合子/供体的中位数为6.4×10⁻⁶。在体外滤膜交配实验中，该益生菌菌株显示获得了vanA万古霉素耐药性。
