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Evolution and utility of a Pseudomonas aeruginosa drug resistance factor
Abstract:
We describe the addition to the Pseudomonas aeruginosa sex factor, FP2, of carbenicillin resistance encoded by the RP1 plasmid. This occurred in a step-wise manner as detected by variations in the characteristics of the FP2-RP1 plasmid aggregate. The addition of the carbenicillin resistance marker to FP2 facilitates estimates of FP2 transfer. Transfer frequencies for the presumed cointegrate plasmid, using carbenicillin selection, approached 10(-1) per donor bacterium. The chromosomal mobilization properties of the derived plasmid, designated pR0271, resembled those of the progenitor plasmid FP2. Plasmid pR0271 was also observed to mobilize a nontransmissible drug resistance plasmid sharing genetic homology at frequencies corresponding to those observed for chromosomal markers proximal to the origin of transfer.
Insights
Researchers added carbenicillin resistance to the Pseudomonas aeruginosa sex factor FP2 using the RP1 plasmid. This new plasmid, pR0271, allows for easier tracking of FP2 transfer and retains similar chromosomal mobilization properties.
Area of Science:
- Microbiology
- Plasmid biology
- Bacterial genetics
Background:
- Pseudomonas aeruginosa sex factor FP2 is a conjugative plasmid.
- RP1 plasmid confers carbenicillin resistance.
- Understanding plasmid interactions is crucial for bacterial genetics.
Purpose of the Study:
- To describe the stepwise addition of carbenicillin resistance to the FP2 plasmid.
- To characterize the resulting cointegrate plasmid and its transfer properties.
- To evaluate the chromosomal mobilization capabilities of the modified plasmid.
Main Methods:
- Stepwise plasmid integration and characterization.
- Conjugation experiments with carbenicillin selection.
- Assessment of chromosomal mobilization.
Main Results:
- Successful stepwise addition of carbenicillin resistance to FP2 via RP1 plasmid.
- Formation of a cointegrate plasmid aggregate (pR0271) with high transfer frequencies (approx. 10(-1) per donor).
- pR0271 demonstrated similar chromosomal mobilization as the progenitor FP2 plasmid.
- pR0271 mobilized a non-transmissible drug resistance plasmid effectively.
Conclusions:
- The integration of carbenicillin resistance onto FP2 provides a reliable marker for studying plasmid transfer.
- The derived plasmid pR0271 is a stable and efficient vehicle for both plasmid transfer and chromosomal mobilization in Pseudomonas aeruginosa.