In situ survival of plasmid-bearing and plasmidless Pseudomonas aeruginosa in pristine tropical waters.
AUTOR(ES)
Cruz-Cruz, N E
RESUMO
Two rare wild-type strains of Pseudomonas aeruginosa were mixed in membrane diffusion chambers and then introduced into a natural freshwater environment for 72 h. The plasmid-containing strain (R serotype 15) and the plasmidless strain (H serotype 5) had initial bacterial densities of 2 x 10(5) cells per ml. Samples collected from the chambers were analyzed for viable and direct counts and for acquired-resistance frequencies. Suspected transconjugant-to-donor ratios ranged from 0.5 to 1.3; transfer percentages ranged from 13 to 70%. [3H]thymidine uptake indicated DNA synthesis in both strains as well as in transconjugants. These studies indicate that rare wild-type bacterial strains with large plasmid loads can survive as well as can bacteria with low plasmid loads when exposed to the in situ conditions of a tropical freshwater habitat. These results also suggest that genetic modification of indigenous microbiota through conjugation or transformation is feasible when rare wild-type strains or genetically engineered microorganisms are released in large numbers in tropical aquatic ecosystems.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=204319Documentos Relacionados
- Volatilization of Mercuric Chloride by Mercury-Resistant Plasmid-Bearing Strains of Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa
- Mercury Resistance in a Plasmid-Bearing Strain of Escherichia coli
- Phenotypic and genotypic comparison of Escherichia coli from pristine tropical waters.
- Simple assay of calcium dependency for virulent plasmid-bearing clones of Yersinia enterocolitica.
- Cell-Free Mercury(II)-Reducing Activity in a Plasmid-Bearing Strain of Escherichia coli
