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Inactivation of phages DS6A and D29 by acetone extracts of Mycobacterium tuberculosis and Mycobacterium bovis
Abstract:
The adsorption rate constant for mycobacteriophage DS6A on clumped cells of Mycobacterium tuberculosis strain H37Rv was found to be 6.33 x 10(-13) ml per min per colony former. Acetone-extracted cells of H37Rv did not absorb phage DS6A. Acetone extracts of cells of H37Rv and of Mycobacterium bovis strain BCG inhibited plaque formation of mycobacteriophage DS6A and of phage D29. Suspensions of these extracts in heart infusion broth with 0.002 M calcium chloride and 1 per cent dioxane required 20 hours of incubation (activation) at 37 degrees C with stirring before they were capable of inactivating phage DS6A, but did not require activation for inhibition of phage D29. Sonication of water mixtures of these extracts for 45 sec yielded suspensions that were highly active against phage DS6A and independent of the 20-hour lag period. Such preparations were also active against phage D29. The extract prepared from cells of BCG was more active than the extract from cells of H37Rv. Water washing of chloroform solutions of each extract did not remove significant amounts of solid material or reduce the phage-inactivating activites of either extract.
Insights
Mycobacterium tuberculosis cells inhibit mycobacteriophages DS6A and D29. Acetone extracts from these cells, when sonicated, rapidly inactivate DS6A and D29, suggesting potential therapeutic applications.
Area of Science:
- Microbiology
- Virology
- Biochemistry
Background:
- Mycobacteriophages are viruses that infect Mycobacterium species.
- Understanding phage-host interactions is crucial for developing phage therapy against tuberculosis.
- Mycobacterium tuberculosis (M. tuberculosis) is a significant human pathogen.
Purpose of the Study:
- To investigate the adsorption rate of mycobacteriophage DS6A on M. tuberculosis.
- To determine the effect of M. tuberculosis cell extracts on phage activity.
- To explore methods for enhancing the phage-inactivating properties of these extracts.
Main Methods:
- Determining the adsorption rate constant of mycobacteriophage DS6A on M. tuberculosis H37Rv.
- Extracting cellular components from M. tuberculosis and Mycobacterium bovis BCG using acetone.
- Assessing the inhibitory and inactivating effects of these extracts on phages DS6A and D29.
- Investigating the role of incubation (activation) and sonication on extract activity.
Main Results:
- The adsorption rate constant for DS6A on M. tuberculosis H37Rv was determined.
- Acetone extracts of M. tuberculosis and BCG inhibited plaque formation for both DS6A and D29.
- A 20-hour activation period was required for extracts to inactivate DS6A, but not D29.
- Sonication of extracts eliminated the activation lag for DS6A inactivation and also rendered them active against D29.
- BCG extracts showed higher activity than H37Rv extracts.
Conclusions:
- M. tuberculosis and BCG cell extracts possess significant phage-inhibiting and inactivating capabilities.
- Sonication is an effective method to rapidly activate these extracts for phage inactivation.
- These findings suggest potential for developing novel anti-mycobacterial agents based on phage-inactivating cellular components.