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Updated: Jul 17, 2026
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Methodology for the Study of Horizontal Gene Transfer in Staphylococcus aureus
Published on: March 10, 2017
A plasmid for diffusible pigment production in Staphylococcus aureus.
The Australian Journal of Experimental Biology and Medical Science
|August 1, 1985
Summary
A Staphylococcus aureus plasmid carrying a pigment gene was identified. Resistance genes, similar to transposon Tn554, were found to insert into the bacterial chromosome during plasmid transduction.
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- Diffusible pigment production in Staphylococcus aureus strains is often linked to specific plasmids.
- Co-transduction of pigment genes with antibiotic resistance markers is a known phenomenon.
Purpose of the Study:
- To investigate the genetic basis of diffusible pigment production in Staphylococcus aureus WG260.
- To characterize the plasmid associated with pigment production and its relationship with antibiotic resistance determinants.
Main Methods:
- Plasmid isolation and characterization.
- Transduction experiments to assess co-transfer of pigment and resistance.
- Analysis of resistance determinant location and potential for chromosomal insertion.
Main Results:
- A c.26 megadalton plasmid was associated with diffusible pigment production in Staphylococcus aureus WG260.
- Inducible erythromycin and spectinomycin resistance determinants, similar to transposon Tn554, were observed to insert into the host chromosome.
- The pigment plasmid could be lost while retaining antibiotic resistance, indicating independent genetic elements.
- This represents the first report of such a transposon-like element on a plasmid in a clinical Staphylococcus aureus isolate.
- The pigment plasmid exists primarily as an open-circular, highly relaxable form.
Conclusions:
- The genetic element conferring antibiotic resistance in this strain is likely a transposon that integrates into the chromosome.
- Pigment production is plasmid-mediated and separable from the chromosomal antibiotic resistance.
- This study highlights novel genetic mechanisms in clinical Staphylococcus aureus isolates.
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