title: Molecular characterization of enterohemorrhagic E. coli O157 isolated from animal fecal and food samples in Eastern China.
abstract: OBJECTIVE
  To elucidate the extent of food contamination by enterohemorrhagic Escherichia coli (EHEC) O157 in Eastern China.
  
  
  METHODS
  A total of 1100 food and animal fecal samples were screened for EHEC O157. Then, molecular characterization of each isolate was determined.
  
  
  RESULTS
  EHEC O157 was isolated as follows: pig feces, 4% (20/500); cattle feces, 3.3% (2/60); chicken feces, 1.43% (2/140); pork, 2.14% (3/140), milk, 1.67% (1/60); and chicken meat, 1.67% (1/60). The stx1, stx2, eae, and hlyA genes were present in 26.7% (8/30), 40% (12/30), 63.3% (19/30), and 50% (15/30) of the O157 isolates, respectively. Molecular typing showed that strains from fecal and food samples were clustered into the same molecular typing group. Furthermore, the isolates from pork and pig feces possessed the same characterization as the clinical strains ATCC35150 and ATCC43889. Biofilm formation assays showed that 53.3% of the EHEC O157 isolates could produce biofilm. However, composite analyses showed that biofilm formation of EHEC O157 was independent of genetic background.
  
  
  CONCLUSIONS
  Animal feces, especially from pigs, serve as reservoirs for food contamination by EHEC O157. Thus, it is important to control contamination by EHEC O157 on farms and in abattoirs to reduce the incidence of foodborne infections in humans.
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China.
authors.forename: Shaohui
authors.identifier: 0000-0003-0170-3309
authors.initials: S
authors.lastname: Wang
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China.
authors.forename: Shuxiao
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China.
authors.forename: Pingping
authors.initials: P
authors.lastname: Liu
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China.
authors.forename: Zixue
authors.initials: Z
authors.lastname: Shi
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China.
authors.forename: Jianchao
authors.initials: J
authors.lastname: Wei
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China.
authors.forename: Donghua
authors.initials: D
authors.lastname: Shao
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China.
authors.forename: Beibei
authors.initials: B
authors.lastname: Li
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China.
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Ma
mesh_terms: D000818:Animals; D018441:Biofilms; D002417:Cattle; D002645:Chickens; D019453:Escherichia coli O157 / Q000302:isolation & purification* / Q000502:physiology; D005243:Feces / Q000382:microbiology*; D005516:Food Microbiology; D008460:Meat / Q000382:microbiology; D013552:Swine