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Updated: Jul 1, 2025
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High-Resolution Comparison of Bacterial Conjugation Frequencies
Published on: January 10, 2019
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Capsules and their traits shape phage susceptibility and plasmid conjugation efficiency
Matthieu Haudiquet1,2, Julie Le Bris3,4, Amandine Nucci3
1Institut Pasteur, Université Paris Cité, CNRS UMR3525, Microbial Evolutionary Genomics, Paris, 75015, France. matthieu.haudiquet@gmail.com.
Nature Communications
|March 6, 2024
Summary
Bacterial capsules significantly impact mobile genetic element infections, influencing phage susceptibility and plasmid conjugation. This reveals how bacterial surface traits shape evolution and gene transfer dynamics.
Area of Science:
- Microbiology
- Bacterial Genetics
- Evolutionary Biology
Background:
- Mobile genetic elements (MGEs) like phages and plasmids drive bacterial evolution by conferring adaptive traits but incur fitness costs.
- Bacterial capsules are known to affect MGE infection, but their precise role is hard to isolate due to complex genetic backgrounds.
- Previous studies faced challenges in quantifying capsule impact due to confounding factors like anti-viral systems and surface receptor variations.
Purpose of the Study:
- To quantify the independent impact of capsule types on phage and plasmid infection in Klebsiella pneumoniae.
- To investigate the relationship between capsule characteristics and conjugation efficiency.
- To link laboratory findings on capsule-mediated infection to natural population dynamics of MGE acquisition.
Main Methods:
- Utilized capsule locus swapping between Klebsiella pneumoniae strains to isolate the effect of capsule type.
- Systematically tested phage susceptibility across different capsule serotypes.
- Assessed conjugation efficiency influenced by capsule volume and pilus structure.
- Performed comparative genomics to correlate lab observations with natural MGE acquisition patterns.
Main Results:
- Capsule swaps demonstrated that serotypes are key determinants of phage susceptibility, systematically inverting infection patterns.
- Capsule type influences conjugation efficiency in both donor and recipient bacteria, linked to capsule volume and pilus structure.
- Lab-identified permissive serotypes correlated with higher conjugative plasmid acquisition in natural populations.
- F-like pili, less sensitive to capsule barriers, are prevalent in plasmids carrying antibiotic resistance and virulence factors.
Conclusions:
- Bacterial capsule traits act as critical regulators of MGE infection, defining distinct pathways for phage and plasmid interactions.
- Capsule properties modulate horizontal gene transfer, influencing the spread of adaptive traits like antibiotic resistance and virulence.
- Understanding capsule-MGE interactions is vital for predicting bacterial population dynamics and the evolution of resistance.
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