Antimicrobial resistance of gram-negative aerobic bacteria isolates from the faeces of diarrhoeic and non-diarrhoeic dogs in Abeokuta, Nigeria

Abstract

The increasing incidence of antimicrobial resistance in pathogenic and commensal Gram-negative bacteria from dogs has continued to raise concerns in veterinary small animal practice and public health. In this study, antimicrobial resistance was investigated in Gram-negative aerobic bacteria isolated from the faeces of diarrhoeic and non-diarrhoeic dogs using the Kirby-Bauer disk diffusion method. Thirty-three isolates belonging to five bacteria genera including Escherichia coli (12), Citrobacter spp (3), Proteus spp (3), Klebsiella spp (9) and Morganella morganii (6) were recovered from diarrhoeic dogs (31). Ninety-four isolates belonging to 12 genera comprising of Escherichia coli (44), Citrobacter spp (5), Proteus spp (9), Klebsiella spp (14), Morganella morganii (1), Burkholderia spp (3), Actinobacillus spp (2), Aeromonas spp (2), Yersinia spp (2), Enterobacter spp (5), Haffinia spp (1) and Serratia spp (6) were obtained from non-diarrhoeic dogs (63). Isolates from diarrhoeic dogs were resistant to ampicillin (84.8%), amoxicillin (63.6%), chloramphenicol (51.5%), ciprofloxacin (18.2%), gentamycin (45.5%), kanamycin (57.6%), nalidixic acid (45.5%), neomycin (42.4%), norfloxacin (24.2%), pefloxacin (27.3%), sulphamethoxazole (72.7%), streptomycin (72.7%) and tetracycline (94.0%). The rate of resistance in isolates from non-diarrhoeic dogs was ampicillin (84.0%), amoxicillin (58.5%), chloramphenicol (51.1%), ciprofloxacin (18.1%), gentamycin (40.4%), kanamycin (67.0%), nalidixic acid (38.3%), neomycin (44.7%), norfloxacin (22.3%), pefloxacin (27.7%), sulphamethoxazole (55.3%), streptomycin (81.4%) and tetracycline (91.5%). All the isolates were resistant to three or more of the tested antimicrobials indicating high levels of multiple antibiotic resistance. Some of the identified organisms have been implicated in clinical infections in dogs. This study showed that dogs may serve as important reservoirs of antimicrobial resistant bacteria transmissible to humans through close contact that exist between man and dogs.

Keywords: Antimicrobial resistance, Gram-negative aerobic bacteria, diarrhooeic faeces, non-diarrhoeic faeces, dogs.