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Intracellular DNA replication and long-term survival of pathogenic mycoplasmas
1Department of Microbiology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA.
Abstract:
We examined intracellular survival and growth of pathogenic mycoplasmas (Mycoplasma penetrans, Mycoplasma pneumoniae and Mycoplasma genitalium) in cultured human cells. By using the eukaryotic nuclear DNA synthesis inhibitor, aphidicolin, we detected the selective synthesis of mycoplasma (My) and mitochondria (Mt) DNA, which could be further differentiated by restriction enzyme analyses. Also, intracellular M. pneumoniae and M. penetrans infectivity of human cells was detected over 6 months using subfractionation of infected cells and determination of mycoIplasma colony forming units (cfu). For M. genitalium, which we failed to re-grow from infected cells, species-specific PCR primers were used to implicate long-term mycoplasma survivability. Data indicated that pathogenic mycoplasmas reside and replicate intracellularly over extended periods in human cells, consistent with the ability of mycoplasmas to circumvent antibiotic therapy and immune surveillance and establish chronic infections.
Insights
Pathogenic mycoplasmas, including Mycoplasma pneumoniae, survive and replicate within human cells for extended periods. This intracellular persistence helps them evade antibiotic treatment and immune responses, leading to chronic infections.
Area of Science:
- Microbiology
- Cell Biology
- Infectious Diseases
Background:
- Pathogenic mycoplasmas are intracellular bacteria known for causing persistent infections.
- Understanding their intracellular survival mechanisms is crucial for developing effective treatments.
Purpose of the Study:
- To investigate the intracellular survival and replication of pathogenic mycoplasmas (Mycoplasma penetrans, Mycoplasma pneumoniae, Mycoplasma genitalium) in human cell cultures.
- To determine the duration of intracellular persistence and its implications for chronic infections.
Main Methods:
- Utilized aphidicolin, a eukaryotic DNA synthesis inhibitor, to selectively detect mycoplasma DNA synthesis.
- Employed restriction enzyme analysis to differentiate mycoplasma and mitochondrial DNA.
- Assessed intracellular infectivity over six months using cell subfractionation and colony-forming unit (CFU) determination.
- Applied species-specific PCR primers to detect Mycoplasma genitalium survivability.
Main Results:
- Selective synthesis of mycoplasma DNA was detected within human cells.
- Intracellular Mycoplasma pneumoniae and Mycoplasma penetrans persisted for over six months.
- Mycoplasma genitalium demonstrated long-term survivability, though regrowth was not achieved.
- Pathogenic mycoplasmas were confirmed to reside and replicate intracellularly for extended periods.
Conclusions:
- Pathogenic mycoplasmas possess the ability to survive and replicate intracellularly within human cells over extended durations.
- This intracellular persistence contributes to their capacity to evade antibiotic therapy and immune surveillance.
- The findings support the role of intracellular residence in the establishment of chronic mycoplasma infections.