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Integration and distribution of Lactobacillus johnsonii prophages
Marco Ventura1, Carlos Canchaya, David Pridmore
1Nestlé Research Center, CH-1000 Lausanne 26, Vers-chez-les-Blanc, Switzerland.
Journal of Bacteriology
|July 18, 2003
Summary
Prophages, remnants of viral DNA, were found integrated into tRNA genes in Lactobacillus johnsonii NCC533. These prophages were specific to certain strains, making up half of the unique DNA in strain NCC533.
Area of Science:
- Microbiology
- Genomics
- Bacteriology
Background:
- Prophages are integrated forms of bacteriophages into bacterial genomes.
- The integration sites and prevalence of prophages can vary significantly between bacterial strains.
- Understanding prophage content is crucial for characterizing bacterial genome diversity and evolution.
Purpose of the Study:
- To investigate the prophage content and integration patterns in Lactobacillus johnsonii strain NCC533.
- To determine the distribution of these prophages in related strains.
- To quantify the contribution of prophage DNA to the overall genome of strain NCC533.
Main Methods:
- Bacteriophage DNA sequencing and analysis.
- Bacterial strain surveying using restriction pattern analysis.
- Whole-genome microarray analysis.
Main Results:
- Two intact prophages were identified integrated into tRNA genes in Lactobacillus johnsonii NCC533, with a third prophage disrupted by integration.
- Prophages were found to be present only in Lactobacillus johnsonii strains exhibiting a highly similar restriction pattern.
- Prophage DNA constituted approximately 50% of the strain-specific DNA in the NCC533 isolate.
Conclusions:
- Prophage integration into tRNA genes is a notable feature of the Lactobacillus johnsonii NCC533 genome.
- The presence of specific prophages is a strong indicator of close genetic relatedness among Lactobacillus johnsonii strains.
- Prophages play a substantial role in shaping the genomic landscape and strain-specific DNA content of Lactobacillus johnsonii.