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Updated: Aug 9, 2026
Invasion of Human Cells by a Bacterial Pathogen
Published on: March 21, 2011
Radiometric study on the invasion capability of Streptococcus pyogenes A49 L-forms in tissue cultures
E Ivanova1, S Andreeva, D Veljanov
1Institute of Microbiology, Bulgarian Academy of Sciences.
Abstract:
By a radiometric method using C14 labelled amino acid mixture it was established that the Streptococcus pyogenes A49 L-forms cells invade tissue cultures MK and F in a similar degree as parent bacterium cells. The L-form cells are not able to enter the HeLa and Pulmo tissue culture cells but the parent bacterium cells produce well expressed peak of isotope take-up at the 8th hour of the observation.
Insights
Streptococcus pyogenes A49 L-form cells invade MK and F tissue cultures similarly to parent cells. However, L-forms cannot enter HeLa and Pulmo cells, unlike parent bacteria.
Area of Science:
- Microbiology
- Cell Biology
- Infectious Diseases
Background:
- Streptococcus pyogenes is a significant human pathogen.
- Bacterial L-forms are cell wall-deficient variants with altered pathogenic potential.
- Understanding bacterial invasion mechanisms is crucial for developing effective treatments.
Purpose of the Study:
- To compare the invasion capabilities of Streptococcus pyogenes A49 L-form cells and their parent bacterium cells.
- To investigate differential invasion patterns across various human tissue culture models.
Main Methods:
- Radiometric method utilizing a C14-labeled amino acid mixture.
- Invasion assays conducted on MK, F, HeLa, and Pulmo tissue culture cells.
- Monitoring isotope uptake over an 8-hour observation period.
Main Results:
- Streptococcus pyogenes A49 L-form cells demonstrated similar invasion levels in MK and F tissue cultures compared to parent cells.
- L-form cells were unable to invade HeLa and Pulmo tissue culture cells.
- Parent bacterium cells showed a distinct peak in isotope uptake at 8 hours in HeLa and Pulmo cultures.
Conclusions:
- Bacterial L-forms exhibit distinct tissue tropism compared to their parent counterparts.
- The ability of Streptococcus pyogenes to invade different host cells varies significantly between L-forms and parent cells.
- These findings highlight the complex interactions between bacterial variants and host tissues.
