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[Comparative study of non-conjugative R-plasmids from enterobacteria and Pseudomonas aeruginosa]
Abstract:
Nonconjugative R-plasmids pBS76 and pBS94 (Sm Su), pBS95 and pBS96 (Sm Su Ap) isolated from clinical strains of Pseudomonas aeruginosa and plasmids pKMR281-pKMN284 (Sm Su), pKMR285-pKMR286 (Sm Su Tc) isolated from clinical strains of enterobacteria have been studied. Restriction maps of these plasmids are presented in the paper with some of plasmid genes for antibiotic resistance localized on them. The resistance determinants of plasmids pBS95 and pBS96 are shown to be included in transposon Tn3612 analogous to Tn3. Plasmids pBS76, pBS94-96 are of the wide host range and belong to incompatibility group P4 (IncQ). Plasmids pKMR281-pKMR286 are mutually incompatible and share the conspicuous DNA homology. They are inherited only by enterobacteria and are compatible with IncQ plasmids but in contrast to them are mobilized by RP4 plasmid with lower frequency.
Insights
This study characterized antibiotic resistance plasmids from Pseudomonas aeruginosa and enterobacteria. Key findings include the identification of transposons and plasmid incompatibility groups, aiding in understanding bacterial resistance mechanisms.
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- R-plasmids carrying antibiotic resistance genes are significant in clinical settings.
- Understanding plasmid diversity and genetic elements is crucial for combating antimicrobial resistance.
Purpose of the Study:
- To characterize nonconjugative R-plasmids isolated from clinical strains of Pseudomonas aeruginosa and enterobacteria.
- To construct restriction maps and localize antibiotic resistance genes on these plasmids.
- To investigate the genetic elements, such as transposons, and incompatibility groups of the studied plasmids.
Main Methods:
- Isolation of R-plasmids from clinical bacterial strains.
- Restriction mapping of plasmid DNA.
- Localization of antibiotic resistance determinants.
- Analysis of transposon content and plasmid incompatibility.
Main Results:
- Restriction maps were generated for plasmids pBS76, pBS94-96 (IncQ, wide host range) and pKMR281-pKMR286 (enterobacteria-specific, mutually incompatible).
- Resistance determinants on pBS95 and pBS96 were identified within transposon Tn3612, analogous to Tn3.
- Plasmids pKMR281-pKMR286 exhibited significant DNA homology and were mobilized by RP4 plasmid at a lower frequency compared to IncQ plasmids.
Conclusions:
- The study elucidated the genetic organization and characteristics of specific R-plasmids from clinical pathogens.
- Identification of transposon elements and incompatibility groups provides insights into plasmid evolution and dissemination.
- These findings contribute to the understanding of antibiotic resistance mechanisms in bacteria.