Antibiogram imprints of E. coli O157:H7 recovered from irrigation water and agricultural soil samples collected from two district municipalities in South Africa

Abstract

ABSTRACT The antibiogram signatures of E. coli O157:H7 (n=46) recovered from irrigation water and agricultural soil samples were assessed using the standard disc diffusion method against a panel of 16 antibiotics and molecular methods. The prevalent antibiotic resistance patterns follow the order: cefuroxime (95.7%), nitrofurantoin (93.5%), ampicillin (73.9%), chloramphenicol (71.7%), cefotaxime (60.9%) and trimethoprim/sulfamethoxazole (58.7%). The antibiotic resistance genes detected in the phenotypically resistant isolates include: tetA, tetB, tetC, catII, sulI, sulII, FOX-, CIT-, MOX-, EBC-type plasmid-mediated AmpC, and bla SHV extended-spectrum beta-lactamase. We conclude that irrigation water and agricultural soil are important reservoirs of multidrug-resistant E. coli O157:H7, hence a potential risk to South Africa’s one-health policy.