Open AccessUse of bioluminescent Escherichia coli O157:H7 to study intra‐protozoan survival of bacteria within Tetrahymena pyriformis
Author(s) -
Nelson Shona M,
Cooper Alison A.A,
Taylor Elaine L,
Salisbury Vyvyan C
Publication year - 2003
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1016/s0378-1097(03)00349-5
Subject(s) - tetrahymena pyriformis , bioluminescence , biology , microbiology and biotechnology , bioreporter , bacteria , escherichia coli , ciliate , colistin , tetrahymena , biochemistry , antibiotics , ecology , gene expression , reporter gene , genetics , gene
A method was developed that enabled real‐time monitoring of the uptake and survival of bioluminescent Escherichia coli O157 within the freshwater ciliate Tetrahymena pyriformis . Constitutively bioluminescent E. coli O157 pLITE27 was cocultured with T. pyriformis in nutrient‐deficient (Chalkley's) and in nutrient‐rich (proteose peptone, yeast extract) media. Non‐internalised bacteria were inactivated by addition of colistin, indicated by a decline in bioluminescence. Protozoa were subsequently lysed with Triton X‐100 which lead to a further drop in bioluminescence, consistent with release of live internal bacteria from T. pyriformis into the colistin‐containing environment. Bioluminescence measurements for non‐lysed cultures indicated that internalised E. coli O157 pLITE27 cells were only slowly digested by T. pyriformis , in both media, over the time period studied. The results suggest that bioluminescent bacteria are useful tools in the study of bacterial intra‐protozoan survival.