Key Findings

The study identified multidrug-resistant Escherichia coli isolates from surface water in north-western Mexico, including international high-risk lineages ST410 and ST617. These isolates carried various AMR genes such as blaTEM-1B, blaCTX-M-15, aadA1, aadA2, aadA5, aac(3)-IIa, aac(3)-IId, aph(3')-Ia, aph(3'')-Ib, aph(6)-Id, floR, cmlA1, lnu(F), mdf(A), sul2, sul3, tet(A), tet(B), dfrA12, and dfrA17. Additionally, mutations in gyrA (S83L, D87N), parC (S80I), and parE (S458A) were found to contribute to fluoroquinolone resistance.