Isolation of multi-drug-resistant strains of Escherichia coli from faecal samples of dogs and cats from Harare, Zimbabwe

Background: The escalation of antimicrobial resistance (AMR) in recent years has been of major public health concern globally. Escherichia coli are amongst the bacteria that have been targeted for AMR surveillance due to their ability to cause infection in both animals and humans. Their propensity to produce extended spectrum beta-lactamases further complicates the choices of treatment regimens. Objectives: To investigate the prevalence of antimicrobial-resistance in E. coli strains isolated from faecal samples of dogs and cats from selected veterinary surgeries and animal shelters from Harare, Zimbabwe. Materials and Methods: A cross-sectional study was carried out to select animals by a systematic random procedure. Faecal samples were collected for culture and isolation of E. coli. Their susceptibility to antimicrobial drugs was assessed using the disc diffusion method. Results: A total of 95% (133/140) of the samples from cats (n = 40) and dogs (n = 93) yielded E. coli. Resistance was recorded for ampicillin (45.9%), trimethoprim-sulphamethoxazole (44.4%), nalidixic acid (29.3%), ceftazidime (15.8%) and azithromycin (12.8%), but not for gentamicin and imipenem. A total of 18% of the isolates were multi-drug-resistant where resistance to nalidixic acid, ampicillin and trimethoprim-sulphamethoxazole predominated. Conclusion: We observed relatively high AMR of E. coli strains against ampicillin. The isolation of multi-drug-resistant strains of E. coli may signal the dissemination of resistance genes in the ecosystem of these bacteria which may have a public health impact.