Pathogenicity of nonstressed, heat-stressed, and resuscitated Listeria monocytogenes 1A1 cells.
The pathogenicity of nonstressed, heat-stressed, and resuscitated cells of Listeria monocytogenes 1A1 was assayed in immunocompromised mice. Cells were stressed by heating them at 56 degrees C for 20 min and were resuscitated by incubation in tryptic soy broth at 25 degrees C. A dose of 10(2) nonstressed and resuscitated cells per mouse was required for pathogenicity; a dose of 10(4) heat-stressed cells per mouse was considerably less pathogenic. Loss of hemolytic activity accompanied the decreased virulence.
McCarthy
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Fishery Research Branch, Food and Drug Administration, Dauphin Island, Alabama 36528.
D000818:Animals; D005260:Female; D006461:Hemolysis; D006358:Hot Temperature; D016867:Immunocompromised Host; D008089:Listeria monocytogenes / Q000472:pathogenicity*; D051379:Mice