title: A stable bioluminescent construct of Escherichia coli O157:H7 for hazard assessments of long-term survival in the environment.
abstract: A chromosomally lux-marked (Tn5 luxCDABE) strain of nontoxigenic Escherichia coli O157:H7 was constructed by transposon mutagenesis and shown to have retained the O157, H7, and intimin phenotypes. The survival characteristics of this strain in the experiments performed (soil at -5, -100, and -1,500 kPa matric potential and artificial groundwater) were indistinguishable from the wild-type strain. Evaluation of potential luminescence was found to be a rapid, cheap, and quantitative measure of viable E. coli O157:H7 Tn5 luxCDABE populations in environmental samples. In the survival studies, bioluminescence of the starved populations of E. coli O157:H7 Tn5 luxCDABE could be reactivated to the original levels of light emission, suggesting that these populations remain viable and potentially infective to humans. The attributes of the construct offer a cheap and low-risk substitute to the use of verocytotoxin-producing E. coli O157:H7 in long-term survival studies.
authors.affiliation: School of Biological Sciences, University of Aberdeen, Aberdeen AB24 3UU, Scotland, United Kingdom.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Ritchie
authors.forename: Graeme R
authors.initials: GR
authors.lastname: Campbell
authors.forename: Jill
authors.initials: J
authors.lastname: Shepherd
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Beaton
authors.forename: Davey
authors.initials: D
authors.lastname: Jones
authors.forename: Ken
authors.initials: K
authors.lastname: Killham
authors.forename: Rebekka R E
authors.initials: RR
authors.lastname: Artz
mesh_terms: D003470:Culture Media; D004251:DNA Transposable Elements; D004784:Environmental Monitoring / Q000379:methods; D019453:Escherichia coli O157 / Q000235:genetics / Q000254:growth & development* / Q000502:physiology; D005618:Fresh Water / Q000382:microbiology*; D015386:Hazardous Substances / Q000032:analysis*; D006801:Humans; D008156:Luciferases / Q000235:genetics; D008163:Luminescent Measurements; D016254:Mutagenesis, Insertional; D012988:Soil Microbiology
chemical_list: D003470:Culture Media; D004251:DNA Transposable Elements; D015386:Hazardous Substances; D008156:Luciferases