EFFECT OF MORTALITY-ENHANCING FACTOR FROM LISTERIA ON EXPERIMENTAL HISTOPLASMOSIS
Abstract
A crude, heat-stable cell extract of Listeria monocytogenes that increases susceptibility of laboratory animals to infections with a variety of bacteria has been previously reported. This preparation was labeled mortality- enhancing factor (MEF). This report describes investigations to determine the effect of MEF on experimental histoplasmosis, principally in Syrian hamsters. In a preliminary study, yeast cells of Histoplasma capsulatum Scritchfield strain were injected intraperitoneally with and without serial dilutions of MEF into mice and hamsters. Most of the animals that received MEF and yeast cells died within 15 days postinoculation. In further experiments to determine minimal amounts of MEF required to increase susceptibility to infection, microconidia from strains No. 5 and Ross were employed. Time to death was reduced from 6 or 9 weeks when strains No. 5 and Ross were injected intraperitoneally; to less than 1 week when the maximum MEF, 14.5 mg per animal, was administered with spores. Once the animals started to die, however, the rate of death and total numbers of dead animals were approximately the same as those for control animals receiving spores alone.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1965
- Accession Number
- AD0459382
Entities
People
- Carl R. Valentine
- William S. Woodrow
Organizations
- United States Army Biological Warfare Laboratories