Dunne W M, Wang W
Henry Ford Health System, Detroit, Michigan 48202, USA.
J Clin Microbiol. 1997 Feb;35(2):388-92. doi: 10.1128/jcm.35.2.388-392.1997.
Thirty-two isolates of vancomycin-resistant Enterococcus faecium (VRE) recovered from 25 patients hospitalized at six hospitals in the metropolitan Detroit, Mich., area over a 32-month period were examined for relatedness by repetitive-sequence PCR (rep-PCR). All isolates were shown to carry the vanA gene by PCR. The rep-PCR patterns generated from each isolate showed that the first three VRE isolates obtained from hospital A between June 1992 and February 1994 were distinct strains. Thereafter, all VRE isolates originating from hospital A and those collected from five other area hospitals had identical rep-PCR patterns. On detailed examination, subcultures of 25 of the 32 VRE isolates produced two distinct colony types characterized phenotypically by a rough and a smooth appearance, respectively. Both colony types retained the vanA locus and the rep-PCR pattern of the primary isolate. These data suggest that a single strain of VRE with the capacity to produce two colonial variants has been disseminated to several Detroit-area hospitals. The clinical significance of the colonial morphotypes is unclear.
在32个月的时间里，从密歇根州底特律市大都会区六家医院住院的25名患者中分离出32株耐万古霉素屎肠球菌（VRE），采用重复序列PCR（rep-PCR）检测其相关性。通过PCR检测发现所有分离株均携带vanA基因。从每个分离株产生的rep-PCR图谱显示，1992年6月至1994年2月期间从医院A获得的前三株VRE分离株是不同的菌株。此后，源自医院A的所有VRE分离株以及从其他五家地区医院收集的分离株具有相同的rep-PCR图谱。经详细检查，32株VRE分离株中的25株传代培养产生了两种不同的菌落类型，分别表现为粗糙型和光滑型。两种菌落类型均保留了原始分离株的vanA位点和rep-PCR图谱。这些数据表明，一种能够产生两种菌落变体的单一VRE菌株已传播至底特律地区的几家医院。菌落形态型的临床意义尚不清楚。
