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Updated: Jun 28, 2025
05:18
High-Resolution Comparison of Bacterial Conjugation Frequencies
Published on: January 10, 2019
10.8K
Diverse and abundant phages exploit conjugative plasmids
Natalia Quinones-Olvera1,2,3, Siân V Owen4,5,6, Lucy M McCully1,2,3
1Department of Biomedical Informatics, Harvard Medical School, Boston, MA, 02115, USA.
Nature Communications
|April 12, 2024
Summary
New plasmid-dependent phages targeting IncP and IncF plasmids are common in wastewater. These phages, mostly non-canonical types like tectiviruses, are crucial for understanding bacterial evolution and horizontal gene transfer.
Area of Science:
- Microbiology
- Virology
- Evolutionary Biology
Background:
- Bacteriophages (phages) are viruses that infect bacteria, influencing bacterial evolution through cell surface interactions.
- Most phages use bacterial chromosomal structures as receptors, but plasmid-dependent phages utilize plasmid-encoded proteins, linking their host range to plasmid mobility.
- Characterization of plasmid-dependent phages is limited, despite their biotechnological potential and unique biology.
Purpose of the Study:
- To systematically discover and characterize novel plasmid-dependent phages targeting IncP and IncF plasmids.
- To investigate the genetic diversity and abundance of these phages in environmental samples.
- To understand the evolutionary role of plasmid-dependent phages in constraining horizontal gene transfer.
Main Methods:
- Utilized a targeted discovery platform to isolate phages from wastewater samples.
- Employed genomic and phylogenetic analyses to characterize the isolated phages.
- Investigated phage-host interactions and receptor usage, including the role of phage holin proteins.
Main Results:
- Identified plasmid-dependent phages targeting IncP and IncF plasmids as common and abundant in wastewater.
- Discovered that most isolated phages (65/66) were non-canonical types, including tectiviruses, ssDNA filamentous phages, and ssRNA phages.
- Demonstrated significant host range variation in plasmid-dependent tectiviruses linked to holin protein differences, and found these phages are often missed in metaviromic analyses.
Conclusions:
- Plasmid-dependent phages are a largely unexplored and genetically diverse group, prevalent in wastewater environments.
- Culture-based phage discovery remains essential, as many plasmid-dependent phages, particularly tectiviruses, are not detected by current metaviromic methods.
- These phages play a significant, under-appreciated role in regulating horizontal gene transfer mediated by conjugative plasmids.
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