Streptococci in the Lesions of Experimental Poliomyelitis in Monkeys

Abstract

Thorough search for bacteria has been made in stained sections of the central nervous system of 60 monkeys in which symptoms and lesions of varying degree, typical of poliomyelitis, had developed following inoculation of virus. Unmistakable Gram-staining cocci and diplococci of varying size, shape and grouping, were found in or adjacent to lesions in 54 of the 60 monkeys. The lesions in the 6 in which diplococci were not demonstrable in the sections available were relatively slight. Three of these 6 died, 12, 18, and 21 days, respectively, after onset of paralysis; the remaining 3 had mild attacks of poliomyelitis and were despatched by anesthesia, respectively on the tenth, eleventh and fourteenth day after the onset of the disease. Of the 54 monkeys in which diplococci were found, 31 were despatched by anesthesia and 23 died from paralysis.

A similar search was made for bacteria in sections of the central nervous system of 60 monkeys in which there were no active lesions of poliomyelitis. These 60 animals were used as controls; 32 were despatched by anesthesia and 28 died from various causes other than poliomyelitis. In none of the sections from the 60 monkeys used as controls were diplococci demonstrable.