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[Function of large plasmids of the plague pathogen].
1All-China Treating-Prophylactic Center of Plague and Brucellosis, China, Girin Province, Baigan.
Genetika
|October 1, 1990
Summary
The largest Yersinia pestis plasmid does not control endotoxin production or nutrient needs. However, it does determine the presence of FI and FII antigens in some strains, suggesting a role in virulence.
Area of Science:
- Microbiology
- Bacteriology
- Genetics
Background:
- Yersinia pestis is a bacterium responsible for plague.
- Plasmids are extrachromosomal DNA elements that can carry genes influencing bacterial traits.
- Understanding plasmid function is crucial for Yersinia pestis research.
Purpose of the Study:
- To investigate the functional role of the largest plasmid in Yersinia pestis.
- To determine which bacterial characteristics are plasmid-mediated versus chromosomally-mediated.
Main Methods:
- Analysis of four virulent Yersinia pestis strains from diverse natural sources.
- Assays to evaluate endotoxin production, fermentation capabilities, nitrate reduction, and nutrient requirements.
- Examination of the genetic basis for FI and FII antigen expression.
Main Results:
- The largest Yersinia pestis plasmid does not mediate endotoxin production, sugar/alcohol fermentation, nitrate reduction, or nutrient requirements.
- FI and FII antigen expression is determined by the largest plasmid in some strains.
- In other strains, FI and FII antigens are chromosomally mediated.
- Genes for FI and FII antigens may reside within a transposon-like DNA fragment.
Conclusions:
- The largest Yersinia pestis plasmid's role in virulence is strain-dependent.
- Plasmid-borne genes, potentially within transposon-like elements, contribute to antigen expression in Yersinia pestis.