Antimicrobial resistance profiles and pathogenic potential of <i>Escherichia coli</i> isolated from household dog faeces in Morogoro, Tanzania

Abstract

Although Escherichia coli are known to be commensal bacteria, they have been associated with enteric and extra-intestinal illnesses in both humans and animals. Between July 2016 and February 2017, a cross sectional epidemiological study was conducted to determine the occurrence and pathogenic potential of antimicrobial resistant E. coli in the faeces of dogs in Morogoro Municipality, Tanzania. Fecal samples were collected from 404 household dogs in different locations of the Municipality and subjected to culture techniques for isolation of E. coli. E. coli isolates were identified by biochemical tests. Sorbitol MacConkey was used for detection of potentially pathogenic E. coli. Confirmed isolates were tested for resistance against eight antimicrobial agents commonly used in treatment of human and animal diseases in Tanzania. Out of the sampled dogs, 73.8% were infected with E. coli. Non-sorbitol fermenting E. coli, a feature of pathogenic strains, constituted 6.04% of all isolates (n=298). The frequency of infection was significantly higher in young dogs as compared to adults. Dog sex, species and health status had no influence on positivity to E. coli. All the isolates were susceptible to gentamycin, norflaxacin and ciproflaxacin; but resistant to erythromycin and cephalothin. Proportions of resistant isolates to other antimicrobial agents were 16.7%, 16.7% and 91.7% for azithromycin, nalidixic acid and amoxicillin respectively. In conclusion, household dogs in the study area are reservoirs of antimicrobial resistant E. coli including potentially pathogenic strains; and are therefore a potential source of human infections with these organisms. Contacts with these companion animals should involve care, particularly when young children are involved.

Keywords: Companion animals, Escherichia coli, sorbitol MacConkey, Tanzania