Brazilian Journal of Veterinary Research and Animal Science (Jan 2023)

Antimicrobial resistance of Shiga toxin‐producing Escherichia coli isolated from sheep

  • Emanuelle Azambuja Lima,
  • Ângela Vitalina Barbosa de Assis Silveira,
  • Lucas Zaiden,
  • Angélica Franco de Oliveira,
  • Eric Mateus Nascimento de Paula,
  • Vera Lúcia Dias da Silva,
  • Cleusely Matias de Souza,
  • Elaine Cristina Castelhano,
  • Ariel Eurides Stella

Journal volume & issue
Vol. 59

Abstract

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The presence of Shiga toxin-producing Escherichia coli (STEC) and resistance to beta-lactams in healthy sheep represents a potential public health risk. This study aimed to characterize STEC isolates in sheep feces for toxin production and resistance to beta lactam antibiotics. In the present study, among the 40 isolates, we found a predominance of subtype Stx1 (22/40), followed by subtype Stx1 + Stx2 (11/40), while the less prevalent group was Stx2 (7/40). Also, we found phenotypical resistance to beta-lactam antibiotics in 50% (20/40) of the strains analyzed, forming two groups, one with resistant isolates and the other with non-resistant isolates. The cytotoxicity of the isolates did not vary among the groups. In addition to having this characteristic, some multiresistant isolates produced significant amounts of toxins. This leads to the conclusion that the mechanisms of antimicrobial resistance via beta lactamases are present in sheep STEC and that the cytotoxicity of those isolates is variable regarding such resistance.

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