scholarly journals Genetic effects of acridines onPseudomonas aeruginosa

1969 ◽  
Vol 13 (1) ◽  
pp. 57-70 ◽  
Author(s):  
Vilma Stanisich ◽  
B. W. Holloway
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Cell Division ◽  
Vegetative Cell ◽  
Normal Growth ◽  
Fold Increase ◽  
Chromosome Transfer ◽  
Recombinant Formation ◽  
Derivatives Of ◽  
Male Strain ◽  
Female Strain

Mutants ofPseudomonas aeruginosamale strains with altered mating properties have been obtained through treatment with nitrogen half mustards. The response varied with the type of male strain. A mutant of the infectious male PTO 13 was obtained which acts as a female strain and has apparently lost the FP sex factor. A mutant of the non-infectious strain 2 male mates not only with strain 1 females, but shows a thousand-fold increase in its ability to mate with strain 2 males, when it can act as either donor or recipient in conjugation. Derivatives of strain 1 males were obtained which had reduced recombinant forming ability.While acriflavine is ineffective in producing such mutants, and has not been shown to cure male strains of their sex factor inP. aeruginosa, it is very effective in inhibiting infectious transfer of FP from FP+to FP−strains. Furthermore, it markedly inhibits recombinant formation in 1 FP−× 1 FP+crosses, and this latter effect is thought to be due to the inhibition of chromosome transfer by the male parent. In view of the almost complete lack of effect of AF on the normal growth ofP. aeruginosait is likely that the control of chromosome replication during vegetative cell division is different from the occurring during conjugation and that the FP factor is involved in this control during conjugation.

scholarly journals Apparent Fusion of the TOL Plasmid with the R91 Drug Resistance Plasmid in Pseudomonas aeruginosa

1977 ◽  
Vol 30 (4) ◽  
pp. 345 ◽  
Author(s):  
GP White ◽  
NW Dunn
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Drug Resistance ◽  
Recombinant Plasmid ◽  
Bacterial Chromosome ◽  
Tol Plasmid ◽  
Chromosome Transfer ◽  
Resistance Plasmid ◽  
Catabolic Plasmid ◽  
Derivatives Of

The TOL catabolic plasmid was shown to be compatible with the R91 drug resistance plasmid. However, the TOL plasmid was extremely unstable in mutant PA03 of P. aeruginosa. By selecting for stabilization of the TOL plasmid in PA03 harbouring R91, it was possible to isolate a strain in which markers from both R91 and TOL appeared to exist in a single recombinant plasmid. This plasmid, pND3, encoded resistance to carbenicillin, was able to transfer at the same frequency as the R91 plasmid and encoded the ability to grow on m-toluate, p-toluate, m-xylene, p-xylene and toluene. In addition, it was shown to be incompatible with the NAH catabolic plasmid and it could be transferred by transduction. The TOL plasmid could stabilize in PA03 harbouring R91 without fusion with R91, and could stabilize in PA03 in the absence of R91. PA03 harbouring either the recombinant plasmid or the stable TOL plasmid in the absence of R91 could promote bacterial chromosome transfer between mutant derivatives of P. aeruginosa strain P AO.

scholarly journals MexAB-OprM Efflux Pump Interaction with the Peptidoglycan of Escherichia coli and Pseudomonas aeruginosa

2021 ◽  
Vol 22 (10) ◽  
pp. 5328
Author(s):  
Miao Ma ◽  
Margaux Lustig ◽  
Michèle Salem ◽  
Dominique Mengin-Lecreulx ◽  
Gilles Phan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Cell Division ◽  
Membrane Proteins ◽  
Outer Membrane ◽  
Efflux Pump ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Active Efflux

One of the major families of membrane proteins found in prokaryote genome corresponds to the transporters. Among them, the resistance-nodulation-cell division (RND) transporters are highly studied, as being responsible for one of the most problematic mechanisms used by bacteria to resist to antibiotics, i.e., the active efflux of drugs. In Gram-negative bacteria, these proteins are inserted in the inner membrane and form a tripartite assembly with an outer membrane factor and a periplasmic linker in order to cross the two membranes to expulse molecules outside of the cell. A lot of information has been collected to understand the functional mechanism of these pumps, especially with AcrAB-TolC from Escherichia coli, but one missing piece from all the suggested models is the role of peptidoglycan in the assembly. Here, by pull-down experiments with purified peptidoglycans, we precise the MexAB-OprM interaction with the peptidoglycan from Escherichia coli and Pseudomonas aeruginosa, highlighting a role of the peptidoglycan in stabilizing the MexA-OprM complex and also differences between the two Gram-negative bacteria peptidoglycans.

scholarly journals Chromosome transfer inPseudomonas aeruginosamediated by R factors

1971 ◽  
Vol 17 (2) ◽  
pp. 169-172 ◽  
Author(s):  
Vilma A. Stanisich ◽  
B. W. Holloway
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Specific Resistance ◽  
Host Chromosome ◽  
Chromosome Transfer ◽  
R Factors

SUMMARYR factors present inPseudomonas aeruginosastrains of clinical origin can be transferred to other strains ofP. aeruginosaand may act to promote host chromosome transfer. In general, their properties are similar to those R factors in Enterobacteria. The different R factors studied vary with respect to transferability, transfer of specific resistance properties, repressibility, and ability to promote chromosome transfer.

scholarly journals exrB: amalB-linked gene inEscherichia coliB involved in sensitivity to radiation and filament formation

1974 ◽  
Vol 23 (2) ◽  
pp. 175-184 ◽  
Author(s):  
Joseph Greenberg ◽  
Leonard J. Berends ◽  
John Donch ◽  
Michael H. L. Green
Keyword(s):  
Escherichia Coli ◽  
Normal Growth ◽  
Filament Formation ◽  
Wild Type ◽  
Sensitive Mutant ◽  
Γ Radiation ◽  
Linked Gene ◽  
Derivatives Of

SUMMARYPAM 26, a radiation-sensitive mutant ofEscherichia colistrain B, is described. Its properties are attributable to a mutation in a gene,exrB, which is cotransducible withmalB. It differs fromuvrA(alsomalB-linked) derivatives of strain B in being sensitive to 1-methyl-3-nitro-1-nitroso-guanidine and γ-radiation, and in being able to reactivate UV-irradiated phage T3. It differs fromexrA(alsomalB-linked) derivatives of strain B in forming filaments during the course of normal growth as well as after irradiation. WhenexrBwas transduced into a K12 (lon+) strain, filaments did not form spontaneously. Three-point transductions established the order of markers asmet A malB exrB. Based on an analysis of the frequency of wild-type recombinants in a reciprocal transduction betweenexrAandexrBstrains, it was inferred that they are not isogenic and that the order of markers ismalB exrA exrB.

scholarly journals c-di-GMP heterogeneity is generated by the chemotaxis machinery to regulate flagellar motility

eLife ◽  
2013 ◽  
Vol 2 ◽  
Author(s):  
Bridget R Kulasekara ◽  
Cassandra Kamischke ◽  
Hemantha D Kulasekara ◽  
Matthias Christen ◽  
Paul A Wiggins ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Cell Division ◽  
Histidine Kinase ◽  
Molecular Basis ◽  
Individual Cell ◽  
Cell Heterogeneity ◽  
Flagellar Motility ◽  
Bacterial Populations ◽  
Phosphorylation State ◽  
Asymmetric Partitioning

Individual cell heterogeneity is commonly observed within populations, although its molecular basis is largely unknown. Previously, using FRET-based microscopy, we observed heterogeneity in cellular c-di-GMP levels. In this study, we show that c-di-GMP heterogeneity in Pseudomonas aeruginosa is promoted by a specific phosphodiesterase partitioned after cell division. We found that subcellular localization and reduction of c-di-GMP levels by this phosphodiesterase is dependent on the histidine kinase component of the chemotaxis machinery, CheA, and its phosphorylation state. Therefore, individual cell heterogeneity in c-di-GMP concentrations is regulated by the activity and the asymmetrical inheritance of the chemotaxis organelle after cell division. c-di-GMP heterogeneity results in a diversity of motility behaviors. The generation of diverse intracellular concentrations of c-di-GMP by asymmetric partitioning is likely important to the success and survival of bacterial populations within the environment by allowing a variety of motility behaviors.

scholarly journals Recalibration of the Pseudomonas aeruginosa Strain PAO Chromosome Map in Time Units Using High-Frequency-of-Recombination Donors

Genetics ◽  
1987 ◽  
Vol 115 (4) ◽  
pp. 611-618
Author(s):  
Kim O'Hoy ◽  
Viji Krishnapillai
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Nalidixic Acid ◽  
High Frequency ◽  
Temperature Sensitive ◽  
Chromosome Transfer ◽  
Chromosome Map ◽  
Entire Chromosome

ABSTRACT High-frequency-of-recombination donors of P. aeruginosa strain PAO were generated using a temperature-sensitive, replication mutant of the IncP-1 plasmid R68, loaded with the transposon Tn2521. Fourteen donors so isolated mobilized the chromosome in a polarized manner from a number of different transfer origins. The donors were used to construct a time of entry map of the entire chromosome and this was achieved by determining the time of entry of 32 randomly dispersed markers in crosses using nalidixic acid to interrupt chromosome transfer. Analysis of the time of entry data enabled the recalibration of the chromosome map to 75 min.

Cell proliferation and morphological patterns in the hydroids Tubularia and Hydractinia

Development ◽  
1967 ◽  
Vol 17 (3) ◽  
pp. 607-616
Author(s):  
Richard D. Campbell
Keyword(s):  
Cell Proliferation ◽  
Cell Division ◽  
Normal Growth ◽  
Tissue Growth ◽  
Body Form ◽  
Tissue Form ◽  
Morphological Patterns

Morphogenesis has been extensively studied in many hydroids, both during normal growth (Kühn, 1914; Berrill, 1961) and during regeneration (Tardent, 1963). Less is known about the patterns of cell proliferation underlying changes in tissue form. In several cases where cell division has been studied, surprisingly little direct correlation was found between areas of apparent morphological growth and patterns of cell proliferation (Overton, 1963; Crowell, Wyttenbach & Suddith, 1965; Shostak, Patel & Burnett, 1965; Wyttenbach, 1965; Campbell, 1967a, b). To explore further the relations between tissue growth and body form, I have examined histologically hydroids of two genera, Tubularia and Hydractinia, each of which has morphological pecularities. Tubularia possesses two whorls of tentacles and one whorl of gonophores, and thus has as many distinct hydranth regions as any hydroid. In the Hydractinia colony, four morphologically distinct polyp types are present.

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