Antibiotics (Jan 2024)

Prevalence of Antimicrobial Resistance in <i>Escherichia coli</i> and <i>Salmonella</i> Species Isolates from Chickens in Live Bird Markets and Boot Swabs from Layer Farms in Timor-Leste

  • Abrao Pereira,
  • Hanna E. Sidjabat,
  • Steven Davis,
  • Paulo Gabriel Vong da Silva,
  • Amalia Alves,
  • Cristibela Dos Santos,
  • Joanita Bendita da Costa Jong,
  • Felisiano da Conceição,
  • Natalino de Jesus Felipe,
  • Augusta Ximenes,
  • Junilia Nunes,
  • Isménia do Rosário Fária,
  • Isabel Lopes,
  • Tamsin S. Barnes,
  • Joanna McKenzie,
  • Tessa Oakley,
  • Joshua R. Francis,
  • Jennifer Yan,
  • Shawn Ting

DOI
https://doi.org/10.3390/antibiotics13020120
Journal volume & issue
Vol. 13, no. 2
p. 120

Abstract

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The rapid emergence of antimicrobial resistance is a global concern, and high levels of resistance have been detected in chicken populations worldwide. The purpose of this study was to determine the prevalence of antimicrobial resistance in Escherichia coli and Salmonella spp. isolated from healthy chickens in Timor-Leste. Through a cross-sectional study, cloacal swabs and boot swabs were collected from 25 live bird markets and two layer farms respectively. E. coli and Salmonella spp. from these samples were tested for susceptibility to six antimicrobials using a disk diffusion test, and a subset was tested for susceptibility to 27 antimicrobials using broth-based microdilution. E. coli and Salmonella spp. isolates showed the highest resistance towards either tetracycline or ampicillin on the disk diffusion test. E. coli from layer farms (odds ratio:5.2; 95%CI 2.0–13.1) and broilers (odds ratio:18.1; 95%CI 5.3–61.2) were more likely to be multi-drug resistant than those from local chickens. Based on the broth-based microdilution test, resistance to antimicrobials in the Timor-Leste Antimicrobial Guidelines for humans were low, except for resistance to ciprofloxacin in Salmonella spp. (47.1%). Colistin resistance in E. coli was 6.6%. Although this study shows that antimicrobial resistance in chickens was generally low in Timor-Leste, there should be ongoing monitoring in commercial chickens as industry growth might be accompanied with increased antimicrobial use.

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