Exploring the Diversity and Dissemination Dynamics of Antimicrobial Resistance Genes in Enterobacteriaceae Plasmids Across Varied Ecological Niches

Antimicrobial resistance (AMR) among the Enterobacteriaceae poses a major public health threat as it encompasses several clinically significant microorganisms responsible for 30% of bacterial human infections limiting treatment options for bacterial infections. Therefore, the presence of plasmid-borne resistance genes in these bacteria in various ecosystems raises significant concerns. In this study, we investigated the distribution of antimicrobial resistance genes (ARGs) in plasmids isolated from human feces, wild birds, and aquaculture environments. Comprehensive antibiotic resistance database (CARD), ResFinder and NCBI databases were used to detect ARGs. The transferability of plasmids was assessed using oriTfinder, and phylogenetic tree based on MOB was generated using FastTree. A total of 453 (wild birds=266, 78=aquaculture, 109=human feces) plasmid sequences were identified and classified into 29 Enterobacteriaceae species while a total of 159 (35%) plasmids harbored the ARGs distributed into 23 species led by Escherichia coli and followed by Klebsiella pneumoniae and Salmonella enterica. Moreover, we detected 197 different ARGs conferring resistance to 13 different classes of antimicrobial agents. Plasmids from E. coli, K.  pneumoniae and S. enterica harboring several ARGs were found in all niches investigated. Moreover, we detected that plasmid were classified into 36 different plasmid replicon types that were distributed among all three ecosystems. Almost 60% of the plasmids that were conferring resistance to at least one antibiotic has transfer potential and among them 40.8% were conjugative while 18.8% were mobilizable. Phylogenetic analysis revealed that Enterobacteriaceae plasmids co-evolve in nature, with widespread ARG dissemination across different ecosystems, highlighting their role in driving AMR within the One Health framework through human-animal-environment interactions.

To Cite This Article: Munir A, Li C, Kolenda R, Gul S, Wang Z and Li R, 2025. Exploring the diversity and dissemination dynamics of antimicrobial resistance genes in enterobacteriaceae plasmids across varied ecological niches. Pak Vet J, 45(2): 662-672. http://dx.doi.org/10.29261/pakvetj/2025.190