AI Insight
This study examined the EmrD efflux pump gene in ten multidrug-resistant uropathogenic E. coli isolates from Iraq, revealing universal presence of the gene but significant genetic diversity among local strains. Sequencing and protein modeling identified mutations in transmembrane regions critical for the pump's substrate transport mechanism, particularly in helices 6 and 12. While EmrD remains structurally conserved across isolates, the observed genetic variations may affect efflux pump efficiency and contribute to differences in antibiotic resistance patterns.
Why it matters
Understanding genetic variation in intrinsic efflux pumps like EmrD could help explain why some urinary tract infections are harder to treat than others, even when bacteria carry similar resistance genes. This knowledge may inform development of efflux pump inhibitors as adjunct therapies to restore antibiotic effectiveness against resistant strains.
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by Svala H. Mahmood, Iman H. F. Alnaqshabandy
Uropathogenic Escherichia coli (UPEC) presents a significant therapeutic challenge due to increasing multidrug resistance (MDR). While acquired resistance mechanisms are well-documented, the genetic variability of intrinsic efflux pumps like EmrD remains less characterized. This study investigated the genomic diversity and structural conservation of the EmrD transporter in ten clinical MDR isolates from the Kurdistan Region, Iraq. Isolates were screened for the emrD and β-lactamase genes, followed by emrD sequencing, phylogenetic analysis, and in silico protein modeling. Results confirmed the universal presence of emrD alongside multiple resistance genes. Phylogenetic analysis identified notable local genetic diversity, including a highly divergent lineage (DUH 11). Protein modeling mapped non-synonymous substitutions to transmembrane helices 6 and 12, regions critical for the “rocker-switch” conformational changes required for substrate translocation. These findings suggest that while EmrD is a stable component of the MDR machinery, localized genomic divergence may potentially influence efflux efficiency among clinical lineages, warranting future functional validation.