TY - JOUR
T1 - Identification of antimicrobial resistance and class 1 integrons in Shiga toxin-producing Escherichia coli recovered from humans and food animals
AU - Singh, Ruby
AU - Schroeder, Carl M.
AU - Meng, Jianghong
AU - White, David G.
AU - McDermott, Patrick F.
AU - Wagner, David D.
AU - Yang, Hanchun
AU - Simjee, Shabbir
AU - DebRoy, Chitrita
AU - Walker, Robert D.
AU - Zhao, Shaohua
N1 - Funding Information:
The study was made possible by grant USDA/NRI 2000-02600 from the U.S. Department of Agriculture.
PY - 2005/7
Y1 - 2005/7
N2 - Objectives: The objective of this study was to identify antimicrobial resistance and class 1 integrons among Shiga toxin-producing Escherichia coli (STEC). Methods: Two-hundred and seventy-four STEC recovered from poultry, cattle, swine and humans were characterized by antimicrobial susceptibility testing, screened for the presence of class 1 integrons by PCR, and assayed for integron transfer by conjugation. Results: Ninety-three (34%) of the isolates were resistant to streptomycin, followed by 89 (32%) to sulfamethoxazole, 83 (30%) to tetracycline, 48 (18%) to ampicillin, 29 (11%) to cefalothin, 22 (8%) to trimethoprim/sulfamethoxazole, 18 (7%) to gentamicin, 13 (5%) to chloramphenicol and 10 (4%) to cefoxitin. Class 1 integrons were detected in 43 (16%) of the 274 isolates. The adenyl acetyltransferase gene, aadA, which confers resistance to streptomycin, was identified in integrons from 41 (95%) of these 43 isolates, and the dfrA12 gene, which confers resistance to trimethoprim, was identified in integrons from eight (19%) of the isolates. The sat1 gene, which confers resistance to streptothricin, an antimicrobial that has never been approved for use in the United States, was identified in integrons from three (7%) of the isolates. Transfer of integrons by conjugation between strains of E. coli resulted in transfer of antimicrobial-resistant phenotypes for ampicillin, chloramphenicol, cefalothin, gentamicin, tetracycline, trimethoprim, sulfamethoxazole and streptomycin. Conclusions: Antimicrobial resistance is common in STEC. Class 1 integrons located on mobile plasmids have facilitated the emergence and dissemination of antimicrobial resistance among STEC in humans and food animals.
AB - Objectives: The objective of this study was to identify antimicrobial resistance and class 1 integrons among Shiga toxin-producing Escherichia coli (STEC). Methods: Two-hundred and seventy-four STEC recovered from poultry, cattle, swine and humans were characterized by antimicrobial susceptibility testing, screened for the presence of class 1 integrons by PCR, and assayed for integron transfer by conjugation. Results: Ninety-three (34%) of the isolates were resistant to streptomycin, followed by 89 (32%) to sulfamethoxazole, 83 (30%) to tetracycline, 48 (18%) to ampicillin, 29 (11%) to cefalothin, 22 (8%) to trimethoprim/sulfamethoxazole, 18 (7%) to gentamicin, 13 (5%) to chloramphenicol and 10 (4%) to cefoxitin. Class 1 integrons were detected in 43 (16%) of the 274 isolates. The adenyl acetyltransferase gene, aadA, which confers resistance to streptomycin, was identified in integrons from 41 (95%) of these 43 isolates, and the dfrA12 gene, which confers resistance to trimethoprim, was identified in integrons from eight (19%) of the isolates. The sat1 gene, which confers resistance to streptothricin, an antimicrobial that has never been approved for use in the United States, was identified in integrons from three (7%) of the isolates. Transfer of integrons by conjugation between strains of E. coli resulted in transfer of antimicrobial-resistant phenotypes for ampicillin, chloramphenicol, cefalothin, gentamicin, tetracycline, trimethoprim, sulfamethoxazole and streptomycin. Conclusions: Antimicrobial resistance is common in STEC. Class 1 integrons located on mobile plasmids have facilitated the emergence and dissemination of antimicrobial resistance among STEC in humans and food animals.
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U2 - 10.1093/jac/dki161
DO - 10.1093/jac/dki161
M3 - Article
C2 - 15911552
AN - SCOPUS:24044544904
VL - 56
SP - 216
EP - 219
JO - Journal of Antimicrobial Chemotherapy
JF - Journal of Antimicrobial Chemotherapy
SN - 0305-7453
IS - 1
ER -