Global High‐Risk Escherichia coli Clones in Moroccan Aquatic Settings: Genomic Evidence of Environmental Dissemination

Background Globally disseminated high‐risk Escherichia coli ( E. coli ) clones are major drivers of multidrug resistance (MDR) and severe clinical infections. Their presence in aquatic ecosystems represents a growing One Health concern, particularly in regions where wastewater management remains limited. Objective This study aimed to investigate the environmental circulation and genomic characteristics of high‐risk E. coli in Moroccan aquatic environments. Methods Water samples were collected between February and June 2024 from seven major rivers and three wastewater treatment plants (WWTPs) across eight Moroccan cities. A total of 22 E. coli isolates were recovered and analyzed by whole‐genome sequencing to determine their sequence types (STs), antimicrobial resistance genes, virulence factors, and plasmid replicon profiles. Results Sixteen isolates originated from rivers (72.7%) and six from WWTPs (27.3%). Thirteen distinct STs were identified, dominated by the globally disseminated high‐risk clones ST44 ( n = 4; 18.2%), ST410 ( n = 4; 18.2%), and ST131 ( n = 3; 13.6%). The most frequent extended‐spectrum β ‐lactamase (ESBL) gene was bla CTX-M-15 ( n = 13; 59.1%). Carbapenemase genes were found in five isolates (22.7%), including bla NDM-5 ( n = 2; 9.1%), bla OXA-48 ( n = 1; 4.5%), bla OXA-181 ( n = 1; 4.5%), bla OXA-484 ( n = 2; 9.1%), and bla OXA-244 ( n = 1; 4.5%), whereas mcr-1.1 was detected in one isolate (4.5%). Plasmid profiling showed a predominance of IncF‐type replicons (IncFIB 81.8%, IncFII 77.3%, and IncFIA 68.2%), along with IncI (36.4%), IncX (13.6%), and IncHI (9.1%). Conclusion This study provides the first genomic evidence of clinically relevant high‐risk E. coli clones and mobile resistance determinants circulating in Moroccan aquatic environments. These findings highlight the urgent need to strengthen integrated One Health surveillance to prevent environmental dissemination and reduce the public health impact of antimicrobial resistance.