Transmission of antibiotic-resistant Escherichia coli between cattle, humans and the environment in peri-urban livestock keeping communities in Morogoro, Tanzania

• We assess transmission of fecal bacteria between cattle, humans and environment.
• We use PFGE fingerprinting to assess genetic relatedness among E. coli isolates.
• We report E. coli with identical PFGE bands from cattle, humans and environment.
• Cattle housing infrastructures is a risk factor for transmission of E. coli.

Urban and peri-urban livestock farming is expanding world-widely because of increased urbanization and demands for food of animal origin. Such farming practices pose a public health risk as livestock are reservoirs of several zoonotic pathogens. In an attempt to determine the fecal transmission between livestock and people, 100 household clusters keeping cattle in close proximity of humans were selected in urban and peri-urban areas of Morogoro in Tanzania. One hundred eighteen ampicillin and tetracycline resistant Escherichia coli (40 from human stool, 50 from cattle feces, 21 from soil and seven from water samples) were isolated from 44 different clusters. Pulsed-field gel electrophoresis (PFGE) of XbaI digested chromosomal DNA was used to compare the genetic relatedness of the ampicillin- and tetracycline-resistant E. coli isolates. Indistinguishable PFGE band patterns of the ampicillin- and tetracycline-resistant E. coli isolates were found in samples from 23 (52%) clusters. This suggests that transfer of fecal microorganisms between cattle, humans, water and soils within the farms and from livestock farms to the neighborhood occurred commonly. Logistic regression showed that animal housing infrastructures (Odd Ratio = 11.2, 95% CI = 1.1–119.3) were associated with E. coli showing identical PFGE types within and between clusters. There is a need to improve animal husbandry and manure management practices to reduce risks of transmission of enteropathogens between livestock and humans in urban and peri-urban farming.