Multidrug Resistance Genomic Island 1 in a subsp. Human Clinical Isolate from France.

genomic island 1 (SGI1) is a multidrug resistance integrative mobilizable element that harbors a great diversity of antimicrobial resistance gene clusters described in numerous serovars and also in . A serious threat to public health was revealed in the recent description in of a SGI1-derivative multidrug resistance island named PGI1 ( genomic island 1) carrying extended-spectrum-β-lactamase (ESBL) and metallo-β-lactamase resistance genes, and , respectively. Here, we report the first description of genomic island 1 (SGI1) in a multidrug-resistant clinical subsp. strain isolated from a patient in France in 2013. Complete-genome sequencing of the strain revealed SGI1 variant SGI1-L carrying resistance genes , , (G), (now referred to as ), and , conferring resistance to trimethoprim, phenicols, tetracyclines, amoxicillin, and sulfonamides, respectively. The SGI1-L variant was integrated into the usual chromosome-specific integration site at the 3' end of the gene. Beyond and , the SGI1 integrative mobilizable element may thus also disseminate its multidrug resistance phenotype in another genus belonging to the tribe of the family . Since its initial identification in epidemic multidrug-resistant serovar Typhimurium DT104 strains, several SGI1 variants, SGI1 lineages, and SGI1-related elements (SGI2, PGI1, and AGI1) have been described in many bacterial genera (, , , , , etc.). They constitute a family of multidrug resistance site-specific integrative elements acquired by horizontal gene transfer, SGI1 being the best-characterized element. The horizontal transfer of SGI1/PGI1 elements into other genera is of public health concern, notably with regard to the spread of critically important resistance genes such as ESBL and carbapenemase genes. The identification of SGI1 in raises the issue of (i) the potential for SGI1 to emerge in other human pathogens and (ii) its bacterial host range. Further surveillance and research are needed to understand the epidemiology, the spread, and the importance of the members of this SGI1 family of integrative elements in contributing to antibiotic resistance development.