Molecular cloning of an erythromycin resistance determinant in streptococci
Molecular cloning of an erythromycin resistance determinant in streptococci
复制标题
链球菌红霉素抗性决定簇的分子克隆
作者：
D. Behnke;J. Ferretti
质粒pDB102（质粒pSM19035的衍生物）的红霉素抗性决定子被克隆到3.6兆道尔顿隐性变形链球菌质粒pVA318的单个HindIII位点中，并通过转化引入血链球菌菌株Challis中。从转化体之一分离的质粒pDB201由载体质粒和pSM19035的1.15兆道尔顿HindIII片段D组成。 HindIII 片段 D 中包含 pSM19035 的两个独特“间隔”序列之一。重组质粒的自退火分子的电子显微照片显示了经典的茎环结构，并且pSM19035的抗性决定簇表现为转座子样结构。 pSM19035 或 pDB201 的红霉素抗性类型或水平没有观察到差异。克隆红霉素抗性决定簇的可用性对于未来链球菌中大环内酯类、林可酰胺类和链霉素 B 抗性质粒的比较研究很有用。
The erythromycin resistance determinant of plasmid pDB102, a derivative of plasmid pSM19035, was cloned into the single HindIII site of the 3.6-megadalton cryptic Streptococcus mutans plasmid pVA318 and introduced into Streptococcus sanguis strain Challis by transformation. Plasmid pDB201, which was isolated from one of the transformants, consisted of the vector plasmid and the 1.15-megadalton HindIII fragment D of pSM19035. HindIII fragment D contained within it one of the two unique "spacer" sequences of pSM19035. Electron micrographs of self-annealed molecules of the recombinant plasmid revealed classical stem-loop structures, and the resistance determinant of pSM19035 appeared as a transposon-like structure. No differences were observed in either the type or the level of erythromycin resistance by pSM19035 or pDB201. The availability of a cloned erythromycin resistance determinant should be useful for future comparative studies of macrolide, lincosamide, and streptogramin B resistance plasmids in streptococci.