title: Class 1 integrons in various Salmonella enterica serovars isolated from animals and identification of genomic island SGI1 in Salmonella enterica var. Meleagridis.
abstract: OBJECTIVE
  To determine the prevalence of integron-mediated antibiotic resistance in a diverse sample set of Salmonella enterica isolated from animals.
  
  
  METHODS
  Multiplex PCR was used to detect class 1 integron gene sequences, and integron gene cassettes were identified by PCR mapping. Susceptibility to 18 antibiotics or antibiotic combinations commonly used in either human or veterinary medicine was measured using a microdilution method, and statistical comparisons of the frequency of resistance between groups were made using Fisher's two-sided probability test. Genotypic comparisons of isolates were made following pulsed-field gel electrophoresis of genomic DNA.
  
  
  RESULTS
  Thirty-two (30.8%) of 104 isolates contained class 1 integron sequences. Integron-positive isolates represented 15 different S. enterica serovars, were obtained from nine different animal species and had a higher frequency of non-integron-mediated antibiotic resistance (P < 0.05) compared with integron-negative isolates. One non-Typhimurium isolate (S. enterica Meleagridis) contained an SGI1 genomic island, including the antibiotic resistance gene cluster.
  
  
  CONCLUSIONS
  These data demonstrate that integron-mediated antibiotic resistance is common among diverse Salmonella serovars, many of them rare. In addition, SGI1 is not limited to Salmonella enterica Typhimurium DT104 or other commonly isolated serovars.
authors.affiliation: Food Safety Center of Excellence, University of Tennessee, 2505 River Drive, Knoxville, TN 37996, USA. pebner@lsuhsc.edu
authors.forename: Paul
authors.initials: P
authors.lastname: Ebner
authors.forename: Kimberly
authors.initials: K
authors.lastname: Garner
authors.forename: Alan
authors.initials: A
authors.lastname: Mathew
mesh_terms: D000818:Animals; D000829:Animals, Domestic; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D005798:Genes, Bacterial / Q000235:genetics*; D032023:Integrons / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D005810:Multigene Family; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019779:Salmonella enterica / Q000187:drug effects / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial