Key Findings

The study identified multiple AMR genes and mutations in E. coli isolates from sternal bursitis in chickens, including beta-lactamases (blaTEM-1B, blaTEM-1A, blaTEM-1C, blaCTX-M-1, blaOXA-10), chloramphenicol resistance genes (catA1, cmlA1, floR), aminoglycoside resistance genes (aph(6)-Id, aph(3")-Ib, aadA1, aadA2b, aadA5, aadA9, aadA13, sat2), quinolone resistance gene (qnrS1), tetracycline resistance gene (tetA), sulfonamide resistance genes (sul1, sul2, sul3), and efflux pump genes (acrF, mdtM, ermE, qacE, qacL, terD, terW, terZ). Mutations in gyrA (p.S83L) and parC (p.E84G, p.S80I) were associated with quinolone resistance, and a mutation in glpT (E448K) was linked to fosfomycin resistance.