An Examination of Pyrogen from Various Sources

Publisher Website
Google Scholar
Abstract
Summary: Three distinct types of fever curves can be stimulated by injection of modifications of the same bacterial culture. Injection of a sterilised whole culture causes a double-peak fever:*** the cell-free filtrate or supernatant liquid of a culture stimulates a single-peak fever, rising to a peak in an average time of 86 minutes if the cells are removed before autoclaving, and a double-peak reaction if the culture is autoclaved before removal of the cells; the fever caused by injection of a suspension of washed bacterial cells is a single-peak fever of the delayed reaction type, reaching its peak in 3 to 4 hours. The results show that certain bacteria probably produce two pyretic substances, one of which, in the viable culture, is dissolved in the medium and stimulates the single-peak fever of the immediate reaction type, and the other is contained mainly in the bacterial cell and stimulates the single-peak fever of the delayed reaction type, a mixture of both causing the double-peak fever. Proteus vulgaris and Ps. fluorescens can produce a volatile depressant substance, which either lowers the body temperature to below normal, or prevents the pyrogen from causing a rise in body temperature. This depressant causes general paralysis if injected in sufficiently large doses, in smaller quantities the most obvious effect is the loss of appetite. It has been shown that any pyrogen test followed by the rabbits refusing to eat for a few days should be examined for other effects of the depressant substance, and should be repeated, taking care to heat the solution to between 30° and 40°C. for about 10 minutes before injection. An investigation of the stability of pyrogen to heat at 120°C. showed that Ps. ***æruginosa, B. subtilis and P. vulgaris produce pyretic substances of similar stability, whereas M. tetragenes produces a much more thermostable substance. The results from the investigation of the stability showed that the pyrogens of P. vulgaris, Ps. æruginosa and B. subtilis are sufficiently labile to require care when using heat during isolation, as approximately 95 per cent. is destroyed after 2 hours at 120°C. Finally it must be emphasised that further investigation into these points would be of little value unless carried out on the pure pyretic substances isolated from various bacterial sources. This work was carried out during the tenure by one of us (D.W.W.) of a Carnegie Scholarship and a Wellcome Research Fellowship to the trustees of which we wish to express our thanks.
Keywords

This publication has 6 references indexed in Scilit: