Identification and molecular characterization of class 1 integrons in multiresistant Escherichia coli isolates from poultry litter.
This study describes the prevalence of arrays of class 1 integron cassettes and Qnr determinants (A, B, and S) in 19 fluoroquinolone-resistant Escherichia coli isolates from chicken litter. qnrS and qnrA were the predominant genes in these fluoroquinolone-resistant isolates, and an uncommon array of aacA4-catB3-dfrA1 gene cassettes from a class1 integron was found. Additionally, aadA1 and dfrA1 gene cassettes, encoding resistance to streptomycin and trimethoprim, constituted the most common genes identified and was located on megaplasmids as well on the chromosome. Antibiotic resistance, pulsed-field gel electrophoresis (PFGE), and plasmid data suggest a genetically diverse origin of poultry E. coli isolates.
Departamento de Biotecnología Marina, Centro de Investigación Científica y de Educación Superior de Ensenada, Baja California, Mexico. eponce@cicese.mx
Elizabeth
E
Ponce-Rivas
María-Enriqueta
ME
Muñoz-Márquez
Ashraf A
AA
Khan
D000818:Animals; D016172:DNA Fingerprinting; D017931:DNA Primers / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000235:genetics; D005243:Feces / Q000382:microbiology*; D024841:Fluoroquinolones; D032023:Integrons / Q000235:genetics*; D010957:Plasmids / Q000235:genetics; D011200:Poultry
D017931:DNA Primers; D029968:Escherichia coli Proteins; D024841:Fluoroquinolones; C485384:Qnr protein, E coli