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Immune-deficient bacteria serve as gateways to genetic exchange and microbial evolution
Wendy Figueroa1,2, Akshay Sabnis1,2, Rodrigo Ibarra-Chávez3,4
1Department of Infectious Disease, Imperial College London, London, UK.
Nature Communications
|April 1, 2026
Summary
Horizontal gene transfer in Staphylococcus aureus is limited between distinct strains, except via lateral transduction. Immune-deficient bacteria facilitate gene acquisition, driving evolution of antibiotic resistance.
Area of Science:
- Microbiology
- Bacterial Evolution
- Genetics
Background:
- Horizontal gene transfer (HGT) is crucial for bacterial evolution.
- Understanding HGT efficiency between distinct bacterial strains is limited.
- Staphylococcus aureus serves as a model for studying HGT mechanisms.
Purpose of the Study:
- To investigate the efficiency of HGT between different Staphylococcus aureus clonal complexes (CCs).
- To identify factors influencing gene transfer frequency in natural conditions.
- To explore the role of bacterial immune systems in regulating HGT.
Main Methods:
- Utilized Staphylococcus aureus strains from different clonal complexes.
- Assessed gene transfer frequencies via various mechanisms, including lateral transduction.
- Analyzed bacterial immune defenses, specifically Type I restriction-modification systems.
- Investigated the prevalence of immune-deficient mutants in S. aureus populations.
Main Results:
- Gene transfer is significantly restricted between S. aureus strains from different CCs.
- Lateral transduction occurs at high frequency, irrespective of CC.
- Immune-deficient strains, lacking Type I restriction-modification systems, readily accept foreign DNA.
- Immune-deficient mutants are widespread and confer an evolutionary advantage through acquisition of beneficial genes like antibiotic resistance.
- These mutants act as gateways for HGT, facilitating the spread of advantageous genes within CCs.
Conclusions:
- Immune-deficient bacteria play a critical role in facilitating HGT and bacterial evolution.
- The trade-off between phage susceptibility and enhanced gene acquisition drives the persistence of immune-deficient mutants.
- These findings underscore the importance of immune-deficient bacteria in the emergence of novel virulence factors and antibiotic resistance in Staphylococcus aureus.
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