Respiration of So-Called Filterable Viruses.

Abstract

Some time ago one of us described a simple micro-respirometer which permits detection of very small amounts of CO_2. 1

By the use of this method we were able to detect production of one cubic millimeter of CO₂ by 15 million staphylococci in less than ten minutes. However, this is not the limit of the sensitiveness of this method, since the time during which measurable amounts of CO₂ may be permitted to accumulate in the respirometer may be extended for days, so that the negative findings obtained by this method are significant.

Having failed to detect by this method evidence of respiration in filtrates of so-called bacteriophage, 1 , 2 we thought it of interest to inquire into the question of respiration (CO₂ production) by other so-called filterable viruses, particularly those of rabies and herpes. Since these viruses cannot be secured free from tissue cells, it was necessary, at the outset, to differentiate, on the one hand, between the oxygen uptake and the respiration proper with production of CO₂, and, on the other hand, between the respiration of tissues as against that of the viruses themselves. The parallel use of Warburg's respirometer to determine oxygen uptake 3 and of our closed cell respirometer 1 gave us the means of fulfilling the first requirement. In order to eliminate the effect of respiration of surviving tissue cells, fresh autopsy material was placed into 50 per cent glycerine and preserved in this condition for months. From time to time samples of these tissues were emulsified and subjected to test. In all, 6 experiments were made with fixed virus and 15 with virus of herpes. Emulsions, made from preserved tissues during the first 8 weeks of ageing in glycerin, showed oxygen uptake and production of CO₂ at approximately the same rate as did normal brain tissue preserved for the same length of time and under similar conditions.