Schiller J, Strom M, Groman N, Coyle M
Antimicrob Agents Chemother. 1983 Dec;24(6):892-901. doi: 10.1128/AAC.24.6.892.
Erythromycin-resistant (Emr) coryneforms from cutaneous lesions and erythromycin-susceptible (Ems) coryneforms from normal skin sites were screened for plasmids. Approximately one-third of the 40 isolates carried one or more plasmids ranging in mass from 2.5 to 36 megadaltons, all exhibiting different restriction enzyme digest patterns. In contrast, only Corynebacterium diphtheriae strains comprising a single cohort of apparently identical Emr, pNG2-carrying isolates have been identified as plasmid carriers. Homology was demonstrated between pNG2 and a number of fragments in restriction enzyme digests of plasmids from both Emr and Ems skin coryneforms under high-stringency conditions. However, none was detected between pNG2 and the genomic or plasmid DNAs of Emr staphylococci or streptococci isolated concurrently with the Emr coryneforms. One coryneform plasmid, pNG34, exhibited extensive homology with pNG2, and many comigrating fragments were observed. Very little relationship was observed between C. diphtheriae and the skin coryneforms when their genomic DNAs were hybridized. The origin and presence of pNG2 in Emr C. diphtheriae is discussed in relation to these findings.
对来自皮肤损伤部位的耐红霉素（Emr）棒状杆菌和来自正常皮肤部位的敏感红霉素（Ems）棒状杆菌进行质粒筛选。40株分离株中约三分之一携带一个或多个质粒，质量范围为2.5至36兆道尔顿，所有质粒均呈现不同的限制性酶切图谱。相比之下，仅白喉棒状杆菌菌株（包含一组明显相同的携带pNG2的耐红霉素分离株）被鉴定为质粒携带者。在高严格条件下，pNG2与来自耐红霉素和敏感红霉素皮肤棒状杆菌的质粒限制性酶切片段之间存在同源性。然而，在与耐红霉素棒状杆菌同时分离的耐红霉素葡萄球菌或链球菌的基因组DNA或质粒DNA与pNG2之间未检测到同源性。一种棒状杆菌质粒pNG34与pNG2表现出广泛的同源性，并观察到许多共迁移片段。当白喉棒状杆菌和皮肤棒状杆菌的基因组DNA杂交时，观察到它们之间的关系非常小。结合这些发现讨论了耐红霉素白喉棒状杆菌中pNG2的起源和存在情况。
