Transduction
One-Sentence Definition
Transduction is phage-mediated transfer of bacterial DNA from one bacterium to another.
Simple Explanation
A virus that infects bacteria accidentally (or specifically) ships bacterial genes to a new host.
Detailed Scientific Explanation
- Generalized transduction: lytic phage packages random bacterial DNA fragments (e.g., classic P1 in E. coli).
- Specialized transduction: temperate phage excises incorrectly and carries flanking bacterial genes (e.g., λ).
- Lysogeny can also bring phage-encoded toxins (phage conversion): diphtheria toxin, cholera toxin, Shiga-like toxins, some staphylococcal toxins.
Mechanism
Phage infection → packaging of bacterial DNA or prophage excision errors → infection of recipient → recombination or lysogeny → new traits.
Clinical Importance
- Toxinogenic conversion creates major pathogens from otherwise milder strains.
- Contributes to accessory genome diversity.
Research Importance
- Classic genetic mapping tool; modern synthetic biology still uses phage-derived parts.
Diagnostic Relevance
- PCR for toxin genes may detect phage-borne virulence factors.
AMR Relevance
- Can move resistance genes in some systems; generally secondary to plasmids/conjugation for MDR hospital epidemics, but relevant in genomic studies.
Related Organisms
- Corynebacterium diphtheriae, Vibrio cholerae, STEC, S. aureus (toxin phages)
Related MOCs
Active Recall Questions
- Generalized vs specialized transduction?
- Give two diseases where phage-encoded toxins matter.
- How is transduction different from transformation?
Connections
- Parent: Horizontal Gene Transfer
- Contrast: Conjugation · Transformation