THE ROLE OF STREPTOCOCCI IN EXPERIMENTAL POLIOMYELITIS OF THE MONKEY

Area of Science:

• Microbiology
• Virology
• Infectious Diseases

Background:

• Previous research suggested streptococci were secondary or agonal invaders in poliomyelitis.
• The etiological relationship between streptococci and the poliomyelitis virus remained unclear.

Purpose of the Study:

• To investigate the source of streptococci recovered from poliomyelitis-infected monkey tissues.
• To determine if streptococci have an etiological or pathological relationship with the poliomyelitis virus.

Main Methods:

• Culturing tissues from monkeys with experimental poliomyelitis.
• Comparing bacterial growth from tissues ground versus fragmented.
• Assessing microbial contamination in different laboratory environments.
• Analyzing air samples for microbial presence.
• Conducting fermentation and serological tests (agglutination, precipitation).
• Performing intracerebral injections in rabbits.

Main Results:

• Streptococci were frequently found as contaminants introduced during tissue grinding.
• Microbial contamination was higher in routine labs compared to highly aseptic environments.
• Streptococci were isolated from the air in the culture facilities.
• No correlation was found between cultures from different parts of the same brain.
• Fermentation and serological tests showed distinct differences between bacteria from various sources.
• Intracerebral injection of isolates caused meningoencephalitis in rabbits, unlike poliomyelitis virus effects.

Conclusions:

• Streptococci recovered from poliomyelitis tissues are likely contaminants, not secondary invaders.
• There is no evidence of an etiological relationship between these streptococci and the poliomyelitis virus.
• The observed meningoencephalitis in rabbits is distinct from poliomyelitis pathology.