Nomenclature of ISCR1 Elements Capable of Mobilizing Antibiotic Resistance Genes Present in Complex Class 1 Integrons

The dissemination of many antibiotic resistance genes has arisen among members of the family Enterobacteriaceae. The dissemination mechanism of these antibiotic resistance genes is closely linked with insertion sequence common region 1 (ISCR1). Thus, caution must he taken in clinical settings to prevent further dissemination of these antibiotic resistance genes. A nomenclature system of ISCR1 variants, important for the antibiotic resistance dissemination, was proposed. The proposed system can designate all ISCR1 variants on the basis of the detection time and by considering amino-acid substitution(s) compared with ISCR1a. This nomenclature system of ISCR1 variants can be applied to 19 groups (ISCR1 to ISCR19) of the ISCR family and help some researchers to correctly designate new ISCR subgroups.