Occurrence and Phenotypic Antimicrobial Resistance of Escherichia Coli and Salmonella Enterica as Well as Coliform Load Recovered from Healthy Dogs in Tamale Metropolis, Ghana

Abstract

Salmonella enterica and Escherichia coli are vital bacteria associated with infections in both humans and animals. Their presence in dogs  expose humans to the risk of infections. This study determined the occurrence and phenotype antimicrobial resistance of Salmonella  enterica and Escherichia coli recovered from healthy dogs in the Tamale Metropolis, Ghana. The study also examined coliform loads in  these dogs. A total of 120 samples from five different parts (anus, mouth, nose, inner ear and outer ear) of apparently 24 healthy dogs  were examined. Isolation and antimicrobial resistance of Salmonella enterica and Escherichia coli were determined according to the  Bacteriological Analytical Manual and the Disc Diffusion methods, respectively. The occurrence of Salmonella enterica was highest at  41.7% and lowest at 8.33% while Escherichia coli in the dogs was highest at 62.5% and lowest at 16.7%. The coliform load was highest at  3.7 log cfu/cm² and lowest at 3.1 log cfu/cm² . The Salmonella enterica isolates were highly resistant to teicoplanin (100%) and tetracycline (89.5%), but susceptible to gentamicin (68.4%). The MAR index ranged from 0.1 to 0.7 and the resistance pattern TecTeCCro  (resistant to teicoplanin, tetracycline, chloramphenicol and ceftriaxone) was the most common. For Escherichia coli, they were highly  resistant to teicoplanin (84.6%) and tetracycline (73.1%), but susceptible to gentamicin (80.8%), ceftriaxone (88.5%) and chloramphenicol  (92.3%). The MAR index ranged from 0.0 to 0.6 and the resistannce pattern Tec (resistant to only tetracycline) was the most common. In  conclusion, this showed that apparently healthy dogs were sources of Salmonella enterica and Escherichia coli. The Salmonella enterica  and Escherichia coli isolates showed varied resistances to antibiotics.