Low D, David V, Lark D, Schoolnik G, Falkow S
Infect Immun. 1984 Jan;43(1):353-8. doi: 10.1128/iai.43.1.353-358.1984.
The genes encoding alpha-hemolysin and mannose-resistant hemagglutination were shown to be closely linked in cloned DNA from two Escherichia coli urinary tract isolates of serotypes O4 (J96) and O6 (C1212). DNA hybridization experiments demonstrated that the hly and mrh gene clusters of other E. coli O6 serotypes were also linked. Colony hybridizations showed that most normal fecal E. coli do not contain hly and mrh DNA but much of the intervening DNA between these two gene clusters is common among all E. coli. We have further demonstrated that there is a small (about 1 kilobase) region of homology located on both sides of the hly sequence and present elsewhere in the C1212 strain. We suggest that linkage of hly and mrh occurred through a transposition event, and we discuss the potential significance of this linkage in the acquisition of virulence determinants by these bacteria.
编码α-溶血素和甘露糖抗性血凝素的基因在来自血清型O4（J96）和O6（C1212）的两株大肠杆菌泌尿道分离株的克隆DNA中显示紧密连锁。DNA杂交实验表明，其他大肠杆菌O6血清型的hly和mrh基因簇也相互连锁。菌落杂交显示，大多数正常粪便大肠杆菌不含有hly和mrh DNA，但这两个基因簇之间的大部分间隔DNA在所有大肠杆菌中是常见的。我们进一步证明，在hly序列两侧存在一个小的（约1千碱基）同源区域，并且在C1212菌株的其他地方也存在。我们认为hly和mrh的连锁是通过转座事件发生的，并且我们讨论了这种连锁在这些细菌获得毒力决定因素中的潜在意义。
