Bacteriophage Inhibition by Serum *

The inactivation of staphylococcus bacteriophage by an artificially produced anti-phagic serum was first reported by Gratia and Jaumain", who also found that normal rabbit serum inhibits staphy phage,-in some instances to a titer. as high as 1: 500. More recently it has been observed (Rosenthal29, Raiga24 25, Biglieri and Fischer4, Applebaum and MacNeal2, Colvin8, and Evans"0) that normal human serum, as well as pus, possesses the power to inhibit staphylococcus and streptococcus bacteriophages. Red blood cells do not influence the action of either staphylococcus or coli bacteriophage. The early studies of d'Herelle'8 led him to state that normal serum has no effect on bacteriophage. At that time he was chiefly concerned with bacteriophages active against members of the enteric group-chiefly coli and dysentery. Since it is rare to find a human serum which inhibits coli bacteriophage, d'Herelle's statement concerning the effect of serum on these phages still holds true. However, anti-coli bacteriophagic serum may be artificially produced following the technic of Bordet and Ciuca5. The term anti-phage, descriptive of the phage-inhibiting principle in serum, was proposed by Sonnenschein". He observed that normal human serum contains no anti-phage for paratyphoid B bacteriophage, but that the serum of an individual infected with B. paratyphosus B and the serum of a carrier of this organism were inhibitory to the bacteriophage. He, therefore, proposed the use of specific bacteriophage and anti-phage for diagnostic serological reactions. Katsu'9 attempted to utilize this method for the diagnosis of Flexner dysentery, but his results were too inconsistent to be of value. Raiga2" has studied this test in connection with therapeutic failure in cases of staphylococcus infection treated with bacteriophage. In those individuals who failed to respond to phage given locally or intravenously, he found in their serum anti-staphylococcus phage antibody, and in addition a considerable amount of anti-streptococcus phagic principle. He deduces that it is the presence of the latter that nullifies the action of the bacteriophage. Both of these prin-