African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 4996

Full Length Research Paper

Comparison of the prevalence of antibiotic-resistant Escherichia coli isolates from commercial-layer and free-range chickens in Arusha district, Tanzania

Bernadether T. Rugumisa
  • Bernadether T. Rugumisa
  • Department of Health and Biomedical Sciences, School of Life Science and Bioengineering, Nelson Mandela African Institution of Science and Technology (NM-AIST), 447 Arusha, Tanzania.
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Douglas R. Call
  • Douglas R. Call
  • Department of Health and Biomedical Sciences, School of Life Science and Bioengineering, Nelson Mandela African Institution of Science and Technology (NM-AIST), 447 Arusha, Tanzania.
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Gaspary O. Mwanyika
  • Gaspary O. Mwanyika
  • Department of Health and Biomedical Sciences, School of Life Science and Bioengineering, Nelson Mandela African Institution of Science and Technology (NM-AIST), 447 Arusha, Tanzania.
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Murugan Subbiah
  • Murugan Subbiah
  • Paul G. Allen School of Global Animal Health, Washington State University, Pullman, WA, USA.
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Joram Buza
  • Joram Buza
  • Department of Health and Biomedical Sciences, School of Life Science and Bioengineering, Nelson Mandela African Institution of Science and Technology (NM-AIST), 447 Arusha, Tanzania.
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  •  Received: 04 August 2016
  •  Accepted: 31 August 2016
  •  Published: 14 September 2016

Abstract

The antibiotic susceptibility of fecal Escherichia coli isolates from commercial-layer and free-range chickens in Arusha district, Tanzania were compared. All the chickens were raised by individual households, but commercial-layer chickens were purchased from commercial vendors, whereas no systematic breeding system was used to produce free-range chickens. A total of 1,800 E. coli isolates (1,200 from commercial-layer chickens and 600 from free-range chickens) were tested for susceptibility to 11 antibiotics by breakpoint assays. All E. coli isolates were susceptible to gentamicin, ceftazidime and cefotaxime. Isolates from commercial-layer chickens had a high prevalence of resistance (32.4-74.5%) for amoxicillin, ampicillin, ciprofloxacin, tetracycline, streptomycin, trimethoprim and sulfamethoxazole, while the prevalence of resistance to these antibiotics was lower (7-31.5%) for free-range chickens (P<0.05). Both groups had a similar prevalence of resistance to chloramphenicol (1.17-1.5%; P>0.05). For antibiotic resistant strains, 64.1 and 91.5% of free-range and commercial-layer isolates, respectively, were resistant to ≥ 2 antibiotics. Commercial-layer chickens harbored significantly more resistant E. coli isolates (P<0.001) than free-range chickens, consistent with more exposure to antibiotics when compared with free-range chickens. Efforts should be directed towards motivating household owners to limit the use of antibiotics when they are investing in these breeds.

 

Key words: Antibiotic resistance, free-range, commercial-layer, Escherichia coli, Arusha, Tanzania.