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Isolation of a cured strain from Corynebacterium diphtheriae PW8
Infection and Immunity
|September 1, 1979
Abstract:
A nonlysogenic, non-toxinogenic strain was isolated from the PW8 strain of C. diphtheriae by two-step ultraviolet induction. This strain was lysed by phages derived from the PW8 strain but not by beta phages from the C7(beta) strain. When this cured strain was lysogenized with phages from the PW8 strain, toxin production by the resulting lysogens was about a half or a quarter of that of the parent strain PW8.
Insights
Researchers isolated a non-toxinogenic Corynebacterium diphtheriae strain. Re-infection with specific phages reduced toxin production, indicating phage influence on diphtheria toxin levels.
Area of Science:
- Microbiology
- Bacteriology
- Virology
Background:
- Diphtheria toxin production in Corynebacterium diphtheriae is mediated by specific bacteriophages.
- Strain PW8 of C. diphtheriae is a known toxigenic strain.
Purpose of the Study:
- To isolate a non-toxinogenic strain of C. diphtheriae from a toxigenic parent strain.
- To investigate the role of specific bacteriophages in regulating diphtheria toxin production.
Main Methods:
- Two-step ultraviolet induction was used to cure the PW8 strain of C. diphtheriae.
- Phage susceptibility testing was performed using phages from PW8 and C7(beta) strains.
- Lysogenization experiments were conducted with the cured strain and PW8 phages.
Main Results:
- A nonlysogenic, non-toxinogenic strain of C. diphtheriae was successfully isolated.
- The cured strain was sensitive to PW8-derived phages but resistant to C7(beta) phages.
- Lysogenization with PW8 phages resulted in reduced toxin production compared to the parent PW8 strain.
Conclusions:
- Specific bacteriophages influence diphtheria toxin production levels.
- The isolated strain provides a tool for studying phage-host interactions in C. diphtheriae.
- Phage-mediated regulation of toxinogenesis is a key factor in diphtheria pathogenesis.