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Updated: Apr 28, 2026
Understanding the Impact of Temperate Bacteriophages on Their Lysogens Through Transcriptomics
Published on: January 5, 2024
Superinfection exclusion reveals heteroimmunity between Pseudomonas aeruginosa temperate phages
In-Young Chung1, Hee-Won Bae, Hye-Jung Jang
1Department of Pharmacy, College of Pharmacy, CHA University, Gyeonggi-do, 463-840, Republic of Korea.
Abstract:
Temperate siphophages (MP29, MP42, and MP48) were isolated from the culture supernatant of clinical Pseudomonas aeruginosa isolates. The complete nucleotide sequences and annotation of the phage genomes revealed the overall synteny to the known temperate P. aeruginosa phages such as MP22, D3112, and DMS3. Genome-level sequence analysis showed the conservation of both ends of the linear genome and the divergence at the previously identified dissimilarity regions (R1 to R9). Protein sequence alignment of the c repressor (ORF1) of each phage enabled us to divide the six phages into two groups: D3112 group (D3112, MP29, MP42, and MP48) and MP22 group (MP22 and DMS3). Superinfection exclusion was observed between the phages belonging to the same group, which was mediated by the specific interaction between the c repressor and the cognate operator. Based on these, we suggest that the temperate siphophages prevalent in the clinical strains of P. aeruginosa represent at least two distinct heteroimmunity groups.
Insights
Clinical Pseudomonas aeruginosa isolates harbor temperate siphages belonging to at least two distinct heteroimmunity groups. This classification is based on genome analysis and the phage c repressor, impacting superinfection exclusion.
Area of Science:
- Microbiology
- Virology
- Genomics
Background:
- Temperate siphages are viruses that infect bacteria and can integrate into the host genome.
- Pseudomonas aeruginosa is an opportunistic pathogen frequently found in clinical settings.
- Understanding phage-host interactions is crucial for developing phage-based therapies.
Purpose of the Study:
- To characterize novel temperate siphages isolated from clinical Pseudomonas aeruginosa.
- To determine the genomic relatedness and heteroimmunity groups of these phages.
- To investigate the role of the c repressor in phage-host interactions.
Main Methods:
- Isolation and sequencing of temperate siphages from clinical Pseudomonas aeruginosa.
- Comparative genome analysis to identify conserved and divergent regions.
- Protein sequence alignment of the c repressor (ORF1) to classify phages.
- Superinfection exclusion assays to confirm heteroimmunity groups.
Main Results:
- Three temperate siphages (MP29, MP42, MP48) were isolated and their genomes sequenced.
- Genomic analysis revealed synteny with known P. aeruginosa phages but divergence in specific regions.
- Phages were classified into two groups (D3112 and MP22) based on c repressor sequence similarity.
- Superinfection exclusion confirmed distinct heteroimmunity between groups.
Conclusions:
- The temperate siphages prevalent in clinical P. aeruginosa strains represent at least two distinct heteroimmunity groups.
- The phage c repressor plays a critical role in mediating superinfection exclusion.
- This classification provides insights into phage diversity and potential applications in P. aeruginosa infection control.
