The Modifying Effects of Bacterial Substances in the Course of Infection With Neurotropic Virus

Abstract

The investigation of Shope (1) concerning the etiology of the swine influenza may be the first experiment on the interaction between a virus and a bacterium. Shope discovered that the disease was caused by a symbiosis of the bacillus, H. influenzae suis, and a virus, i.e, the bacillus alone would not produce the disease; the virus alone produced an extremely mild, but spontaneously transmissible infection. Both agents were needed to reproduce the clinical syndrome. Horsf all and McCarty (2) reported a study on the effects of inoculating mice with both a virus and a bacterium in the course of investigations concerned with problems relative to the pathogenesis of primary atypical pneumonia. They considered that, when the first experiments were carried out, either of two possible results might develop; first, that streptococcus MG would have no discernible influence on the course of an infection induced by pneumonia virus of mice (PVM); or second, that it might, by contributing to the establishment of a complex infection, cause the results to be more severe than those of infections induced by PVM alone. However they found that, surprisingly, neither possibility evolved; instead, the inoculation of streptococcus MG in mice which previously had been inoculated with PVM resulted in a distinctly less severe infection. After investigating on this unexpected finding in detail, they obtained certain polysaccharide preparations derived from various bacterial species, as well as similar materials from various origins other than bacteria, as agents of the modifying effect in the course of infection with PVM. Thereafter, they (3) (4) (5) (6) (7) studied on the inhibitory effect of polysaccharide derived from the bacterial origins on mumps virus multiplication. Volkert, Pierce, Horsf all, and Dubos (8) showed that following infection with small amounts of either PVM or influenza A virus (PR 8) intranasally, tuberculous lesions in the lungs of mice developed more rapidly and became more extensive than in control animals infected only with tubercle bacilli. Recently, Buddingh (9) reported that combinated viral and bacterial infection established by intra-amniotic inoculation with influenza C virus on the 14th followed * I .N.=intranasal.

The Modifying Effects of Bacterial Substances in the Course of Infection With Neurotropic Virus

“…The GDVII strain of mouse encephalomyelitis virus as described in the previous report (1) was employed.…”

“…The E. coli was selected among the bacteria having inhibitory effect described in the previous reports (1) (2), and the experiments concerning the inhibitory effect of E. coli on the GDVII strain of mouse encephalomyelitis virus (GDVII virus) were investigated in detail (3) (4). The results obtained were the :following data: the administration with E. coli before virus inoculation was effective on the inhibition of the infection with the GDVII virus, but when the E. coli was given to the mice following the virus infection the effect of the bacteria was not evident ; it was most significant in the case of the same route of administration with the bacteria and the virus; the bacteria itself had not direct virucidal activity ; the effect of the bacteria was not related with the antibody against this bacteria; and no evidence of inapparent infection in the survival mice was presented.…”