HEAT-STABLE ENTEROTOXIN PRODUCED BY SHIGELLA-FLEXNERI

  • 1 January 1978
    • journal article
    • research article
    • Vol. 25  (3) , 165-171
Abstract
Filtrates and ultrasonic extracts of S. flexneri showed rapid permeability factor (PF) test and proved positive in suckling mice and ligated rabbit loop tests within 4 h. Delayed PF was not detected and the rabbit loop dilatation test read after 18-24 h, the mouse pad edema reaction, the test for elongation effect of [Chinese hamster ovary] CHO cells were also negative. In the delayed PF test a strong blanching effect was observed. A filtrate of an Ent- Escherichia coli strain was positive only in the rapid PF test, while filtrate and ultrasonic extract prepared from an Ent+ E. coli strain showed a positive reaction in all tests of enterotoxins (ST [heat-stable] and LT [heat labile]) including the rapid PF test. Ultrasonic extracts of a S. flexneri and an Ent- E. coli strain concentrated by freeze-drying were fractionated on Sephadex G-100 column. S. flexneri fractions of 60-70 ml were positive for rapid PF, dilatation capacity in suckling mice, and the blanching effect in the delayed PF test. No positive reaction was found in the delayed PF test and in CHO cell culture. Similar fractions of Ent- E. coli carried substances responsible for the rapid PF and the blanching effect, but without suckling mice positivity.