title: Antimicrobial resistance markers of class 1 and class 2 integron-bearing Escherichia coli from irrigation water and sediments.
abstract: Municipal and agricultural pollution affects the Rio Grande, a river that separates the United States from Mexico. Three hundred and twenty-two Escherichia coli isolates were examined for multiple antibiotic resistance phenotypes and the prevalence of class 1 and class 2 integron sequences. Thirty-two (10%) of the isolates were resistant to multiple antibiotics. Four (13%) of these isolates contained class 1-specific integron sequences; one isolate contained class 2 integron-specific sequences. Sequencing showed that the class 1 integron-bearing strain contained two distinct gene cassettes, sat-1 and aadA. Although three of the four class 1 integron-bearing strains harbored the aadA sequence, none of the strains was phenotypically resistant to streptomycin. These results suggest that integron-bearing E. coli strains can be present in contaminated irrigation canals and that these isolates may not express these resistance markers.
authors.affiliation: Texas A&M University, College Station, Texas, USA.
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Roe
authors.forename: Everardo
authors.initials: E
authors.lastname: Vega
authors.forename: Suresh D
authors.initials: SD
authors.lastname: Pillai
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification*; D005819:Genetic Markers; D019015:Geologic Sediments / Q000382:microbiology*; D032023:Integrons / Q000235:genetics*; D010641:Phenotype; D014871:Water Microbiology
chemical_list: D000900:Anti-Bacterial Agents; D005819:Genetic Markers