SOME PROPERTIES OF POLIOMYELITIS VIRUS

Abstract

The authors concentrated poliomyelitis virus by distillation in vacuo so that the residue was more potent than the original filtrate or brain cord suspension from which the filtrates were made. The virus remains potent in the "concentrate," even though the solution contains NaCl to saturation, for more than 4 mos. On the other hand, streptococci, isolated from cases of poliomyelitis, concentrated in a filtrate of normal brain cord suspension, were no longer viable after 35 days. This would tend to discredit the streptococcus as the specific etiologic agent. The "concentrates" can be dialyzed against sterile distilled water without essential loss of potency. The virus is present in the water-soluble portion of these dialysates and not in the water-insoluble or euglobulin fraction; it is not demonstrable in the concentrated diffusate. The virus is present in the globulin precipitate, obtained either from the regular filtrates or from the "dialysates," following half saturation with (NH4)2SO4. Complete saturation of the thoroughly centrifuged supernatant so obtained, gives a precipitate (albumin fraction) which does not contain the virus. The virus is not demonstrable in the concentrated final supernatant after complete saturation with (NH4)2SO4. These fractional precipitations, together with the facts obtained after dialysis, indicate that the virus remains constantly associated with the pseudoglobulin fraction of the proteins. In 1 of 6 exps., the feces, obtained after feeding large volumes of poliomyelitis virus, gave an inoculum with which the disease was experimentally produced. The concentration of feces from acute cases gave negative results in the 3 groups investigated. These exps. would indicate that the virus does not commonly pass through the intestinal tract of monkeys in an infective form. Many attempts were made to cultivate a significant organism from the highly infective concentrates and dialysates, with negative results. Streptococci were found as a contaminant in 1 instance only. Stained smears also showed nothing that could not be found in the "dialysate" from normal sources.