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Enterotoxin and cytotoxin production by Salmonella enteritidis strains isolated from gastroenteritis outbreaks
Author(s) -
Rumeu M.T.,
Suárez M.A.,
Morales S.,
Rotger R.
Publication year - 1997
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/j.1365-2672.1997.tb03293.x
Subject(s) - enterotoxin , toxin , microbiology and biotechnology , biology , escherichia coli , salmonella enteritidis , salmonella , vero cell , cytotoxic t cell , chinese hamster ovary cell , chemistry , cell culture , biochemistry , bacteria , in vitro , genetics , gene
Seventy‐six Salmonella enteritidis , three Salmonella virchow and one Salmonella braedenrup strains were screened for enterotoxigenicity by using the Chinese hamster ovary (CHO), Y1 adrenal, Vero and HeLa cell tests. All the strains gave positive reactions for enterotoxin production, except one, and the relative sensitivity to the toxin exhibited by the different cell lines was evaluated. An enterotoxic activity has been identified in sonicated extracts of Salm. enteritidis: This enterotoxin was purified on Agarose A‐5m (Bio‐Rad) and Superose 12 HR 10/30 column. The enterotoxic activity was eluted from the Superose column in the first peak. Like Vibrio cholerae toxin CT and Escherichia coli enterotoxin LT, it was blocked by GM 1 ganglioside, but at a higher concentration. In addition, a cytotoxic factor has been partially identified. The procedure for isolating the cytotoxin included ammonium sulphate precipitation, size‐exclusion chromatography and anion exchange chromatography. This cytotoxin factor caused inhibition of protein synthesis in cultured cells, as determined by flow cytometry and [ 3 H]‐leucine incorporation. Flow cytometry analysis also showed an activation of CHO cells when exposed to this cytotoxic factor resulting in a state of active growth. Cytotoxic activity was not blocked by gangliosides.