Genomic islands associated with the dissemination of multidrug resistance in clinically important pathogenic bacteria

To elucidate the role of genomic islands (GIs) as key vehicles of horizontal gene transfer in disseminating antibiotic-resistance genes (ARGs) across bacterial species and in fostering multidrug-resistant (MDR) strain emergence, and to provide a comprehensive overview of current knowledge.

We integrated recent literature on mobile genomic islands (GIs), summarized their basic architecture and functional features, systematically catalogued the types/subtypes of resistance islands identified in major epidemic pathogens (Salmonella, Proteus mirabilis, Staphylococcus aureus, Acinetobacter baumannii, etc.), and delineated their horizontal transfer mechanisms.

(1) GIs can integrate into host chromosomes, excise under specific cues, and transfer to new recipients, thereby facilitating the spread of clinically important ARGs. (2) Diverse novel multidrug-resistant genomic islands have been characterized in the above pathogens.

GIs are one of the key vehicles that facilitate the dissemination of ARGs and the evolution of bacterial multidrug resistance. A systematic understanding of their structure, transfer mechanisms and core functions offers a reference framework for future surveillance of multidrug-resistant genomic islands and for developing countermeasures against antimicrobial resistance.