Integration of the IS<i>CR1</i> element and its nearby sequences, including the blaNDM-1 gene region, into a class 1 integron.

The circular transposition intermediate generated by ISCR1 is shown above. Integration at the sul1 locus of a class 1 integron resulted in the genetic environment identified as flanking the blaNDM-1 ‘common neighbourhood’ region in pLK75 and pLK78 (pLK78 is shown here). The remarkable features are indicated: IRs, inverted repeats; IntI, integrase gene of class 1 integron; ISCR1 (orf513), integrase gene of ISCR1; oriIS, origin of replication of the ISCR element.