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

OBJECTIVE

To perform genomic analysis on plasmid-mediated quinolone-resistance (PMQR) in Shigella.

METHODS

We assembled a global collection of 8325 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 the 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 analysed. qnrS was the most predominant PMQR gene (62.05%), followed by qnrB (38.76%). One hundred and eight sequence types 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 out of 8325), tet(B) (2398 out of 8325), and blaTEM-1 (2232 out of 8325) the most prevalent. PMQR-positive Shigella from developed countries displayed a significant decreasing trend in the abundance of ARGs and collection year and displayed the opposite trend in the abundance of virulence factors between developed and developing countries (P < .001). Correlation analysis demonstrated that mobile genetic elements constitute principal vectors for the spread of PMQR genes. The abundance of plasmid replicons positively correlated with the abundance of ARGs (P < .001), demonstrating the spread of plasmid-driven ARGs 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.