Global distribution and genomic architectures of plasmid-mediated quinolone resistance genes in Shigella from 1998 to 2025.

BACKGROUND Quinolone-resistant Shigella has emerged as a significant global public health challenge.

METHODS We assembled a global collection of 8325 plasmid-mediated quinolone resistance (PMQR)-positive Shigella isolates (1998-2025) and subjected them to comprehensive genomic analysis.

RESULTS Geographically, the isolates spanned 37 countries, with the majority sourced from the United States (47.02%) and United Kingdom (32.28%). Eight distinct PMQR genes-aac(6')-Ib-cr, oqxAB, qepA, qnrA, qnrB, qnrD, qnrS, and qnrVC-were identified in the Shigella analyzed. qnrS was the most predominant PMQR gene (62.05%), followed by qnrB (38.76%). One hundred and eight sequence types (STs) were identified among the PMQR-positive Shigella isolates, with ST152 predominating (59.51%). Notably, multiple antibiotic resistance genes (ARGs) were universal in PMQR-positive Shigella, with aph(6)-Id (5825/8325), tet(B) (2398/8325), and blaTEM-1 (2232/8325) most prevalent. PMQR-positive Shigella from developed countries displayed a significant decreasing trend in ARGs abundance as collection year and the opposite trend in the abundance of virulence factors (VFs) between developed and developing countries (P < 0.001). Correlation analysis demonstrated the mobile genetic elements constitute principal vectors for PMQR genes spread. Plasmid replicons abundance positively correlated with ARGs abundance (P < 0.001), demonstrating plasmid-driven ARGs spread in PMQR-positive Shigella. In addition, high genetic similarity among geographically dispersed PMQR-positive Shigella isolates implies intercountry dissemination.

CONCLUSIONS These findings elucidate PMQR-positive Shigella genomic characteristics and transmission dynamics, necessitating global surveillance reinforcement against this antimicrobial resistance threat.