Wildlife-associated ecosystems in Algeria harbor internationally distributed ESBL-producing clones and plasmids, including a CTX-M-15 Klebsiella pneumoniae ST17 lineage associated with a conserved IncFIB(K) resistance plasmid

Expanded-spectrum cephalosporin-resistant Enterobacterales (ESC-R-E) have disseminated beyond clinical settings, but their occurrence and genomic epidemiology in wildlife remain poorly characterized, particularly in low- and middle-income countries. ESC-R may result from the production of extended-spectrum β-lactamases (ESBLs) or AmpC-type cephalosporinases. We investigated the prevalence, resistance mechanisms, and population structure of ESC-R-E in free-ranging wildlife, captive wild animals, and zoo workers in Algeria. Between October 2021 and June 2023, 1,899 fecal samples were collected across six Algerian provinces. ESC-R-E isolates were recovered by selective culture and characterized by antimicrobial susceptibility testing, and whole-genome sequencing. Overall, 73 ESC-R-E isolates (3.9%) were identified, including seven OXA-48-like carbapenemase co-producers (0.4%). Carriage was significantly higher in captive animals (13.5%) than in free-ranging wildlife (1.6%) or zoo workers (7.7%). Among the 66 ESBL-producing isolates analyzed, CTX-M enzymes predominated ( n = 61), particularly CTX-M-15 ( n = 53). Klebsiella pneumoniae was the predominant species ( n = 33), with ST17 accounting for 27/33 isolates. Closely related CTX-M-15-producing ST17 isolates were recovered from captive animals, free-ranging wildlife, and a zoo worker and carried an IncFIB(K) plasmid harboring bla CTX-M-15 within a multidrug resistance region closely related to globally disseminated plasmids. Globally disseminated high-risk Escherichia coli clones were also detected, namely ST167, ST361, ST410, and a persistent ST38 lineage in Algerian wildlife since 2016. These findings demonstrate the circulation of high-risk Enterobacterales lineages and mobile resistance plasmids in Algerian wildlife-associated ecosystems and highlight the need for integrated One Health surveillance of antimicrobial resistance at the human-animal-environment interface. IMPORTANCE Wildlife is increasingly recognized as a potential reservoir and sentinel for antimicrobial resistance, yet genomic data from low- and middle-income countries remain scarce. This study provides one of the largest genomic investigations of expanded-spectrum cephalosporin-resistant Enterobacterales in wildlife from North Africa. We demonstrate that internationally disseminated high-risk Klebsiella pneumoniae and Escherichia coli lineages, together with globally distributed CTX-M-15-carrying plasmids, are circulating among captive animals, free-ranging wildlife, and humans in zoological environments. The recovery of closely related K. pneumoniae ST17 isolates from different host species highlights the potential for antimicrobial resistance dissemination across the human-animal-environment interface. These findings extend the known ecological range of clinically important resistant Enterobacterales beyond healthcare settings and identify wildlife-associated ecosystems as part of the broader antimicrobial resistance network. Our study underscores the value of integrating wildlife into One Health surveillance programs to better understand and mitigate the environmental spread of antimicrobial resistance.