title: Characterization of enterotoxin produced by four Yersinia enterocolitica strains of pig origin.
abstract: All four isolates of Yersinia enterocolitica and one isolate of Y. frederiksenii from pigs were found to be enterotoxigenic. Whole-cell preparations of Y. enterocolitica isolates did not induce any change in the rabbit ligated gut test after 6 and 18 h of inoculation, but Y. frederiksenii on the other hand showed a positive gut response at 18 h. Cell-free supernatant (CFS) of all five isolates induced dilatation in the rabbit gut up to 6 h, after which Y. enterocolitica became negative, while Y. frederiksenii continued to show a reaction up to 18 h. CFS of all five isolates were also found positive with the infant mouse test. Of the five isolates of Yersinia, three gave a positive reaction for the permeability factor on rabbit skin. Yersinia enterotoxin could be concentrated by methanol extraction. It was stable at 100 degrees C for 20 min and at 120 degrees C for 15 min. However, its activity was lost at low (2.0) and high pH (10.0). Enterotoxic preparations of Y. enterocolitica lost part of their enterotoxic activity upon dialysis.
mesh_terms: D000818:Animals; D002199:Capillary Permeability; D004768:Enterotoxins / Q000096:biosynthesis* / Q000302:isolation & purification; D006863:Hydrogen-Ion Concentration; D007082:Ileum; D000432:Methanol; D051379:Mice; D011817:Rabbits; D013552:Swine / Q000382:microbiology; D013696:Temperature; D015007:Yersinia / Q000302:isolation & purification / Q000378:metabolism; D015008:Yersinia enterocolitica / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D004768:Enterotoxins; D000432:Methanol