title: [Detection of the viable but nonculturable Escherichia coli O157:H7 in aquatic microcosm].
abstract: OBJECTIVE
  This study is to monitor the survival of E. coli O157:H7 in the aquatic microcosm from Han River and explore the feasibility of fluorescence staining, heterotrophic plate count and ELISA in detection of viable but nonculturable E. coli O157:H7.
  
  
  METHODS
  E. coli O157:H7 were added into aquatic microcosm from Han River and cultured with low temperature and oligo-nutrition. Then the survival of E. coli O157:H7 were real-time monitored by acridine orange direct count (AODC), direct viable count (DVC)-CTC staining, DVC-nalidixic acid (NA) staining, heterotrophic plate count (HPC) and ELISA.
  
  
  RESULTS
  E. coli O157:H7 can be converted to a viable but nonculturable state in the aquatic microcosm from Han River 58 days after cultured at 4°C with oligo-nutrition. The amount of viable E. coli O157:H7 was measured as 1.2 × 10(5) CFU/ml by DVC-CTC and 9.0 × 10(4) CFU/ml by DVC-NA, whereas the amount of culturable bacterial determined by HPC is 0. The amounts of bacteria determined by ELISA are basically stable within 58 days around 10(6) CFU/ml.
  
  
  CONCLUSIONS
  E. coli O157:H7 can be converted into a viable but nonculturable state in Han River water at 4°C with oligo-nutrition, and ELISA combined with fluorescence staining and heterotrophic plate count can be used in quantitative detection of the viable but nonculturable E. coli O157:H7.
authors.affiliation: MOE Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science & Technology, Wuhan 430030, China.
authors.forename: Zhong-Jie
authors.initials: ZJ
authors.lastname: Luo
authors.forename: Zhuo-Sheng
authors.initials: ZS
authors.lastname: Zhou
authors.forename: Chun-Hui
authors.initials: CH
authors.lastname: Hao
authors.forename: Yin-Sheng
authors.initials: YS
authors.lastname: Guo
authors.forename: Hong-Yan
authors.initials: HY
authors.lastname: Liu
authors.forename: Hua-Ying
authors.initials: HY
authors.lastname: Zheng
authors.forename: Zheng
authors.initials: Z
authors.lastname: Huang
mesh_terms: D015169:Colony Count, Microbial; D003470:Culture Media; D019453:Escherichia coli O157 / Q000302:isolation & purification* / Q000502:physiology; D050296:Microbial Viability; D045483:Rivers / Q000382:microbiology; D014871:Water Microbiology
chemical_list: D003470:Culture Media