title: [Variability in tellurite resistance and the ter gene cluster among Escherichia coli O157 isolated in food from 2005 to 2007].
abstract: OBJECTIVE
  To investigate the presence of tellurite resistance (ter) gene cluster and its resistance in Escherichia coli 0157 strains collected by national foodborn disease surveillance system from 2005 to 2007.
  
  
  METHODS
  The ter gene cluster was tested by PCR. Tellurite resistance was evaluated by plate dilution method.
  
  
  RESULTS
  Of the investigated 89 E. coli strains,the presence of ter gene cluster was found in 51 strains. They were separately from 41 of 42 E. coli O157: H7 strains,all of 6 strains of O157 : NM (non-mobile flicH7 positive) and only 3 of 41 O157: NM (flicH7 negative)/O157: hund strains. The 51 strains with ter gene cluster were resistance to the high level of potassium tellurite. The MIC was from 64-512 microg/ml. In contrast, the MIC of most of 38 strains without ter gene cluster was from 2-16 microg/ml. Only one strain was 128 microg/ml. 28 of 29 stx-positive E. coli isolates contained the ter gene cluster and had the high levels of tellurite resistance.
  
  
  CONCLUSIONS
  E. coli 0157 from food had the diversity levels of tellurite resistance. The presence of the ter gene cluster had significant associated with the high levels of tellurite resistance.
authors.affiliation: Institute of Nutrition and food Safety, China CDC, Beijing 100021, China. lilibaisun@126.com
authors.forename: Li
authors.initials: L
authors.lastname: Bai
authors.forename: Yinping
authors.initials: Y
authors.lastname: Dong
authors.forename: Yunchang
authors.initials: Y
authors.lastname: Guo
mesh_terms: D024881:Drug Resistance, Bacterial / Q000235:genetics*; D019453:Escherichia coli O157 / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D029968:Escherichia coli Proteins / Q000235:genetics*; D005516:Food Microbiology; D008826:Microbial Sensitivity Tests; D005810:Multigene Family; D013691:Tellurium / Q000494:pharmacology*
chemical_list: D029968:Escherichia coli Proteins; C119920:tellurite resistance protein B, E coli; C026660:tellurous acid; D013691:Tellurium