Murein and the Outer Penetration Barrier of Escherichia coli K-12, Proteus mirabilis, and Pseudomonas aeruginosa
AUTOR(ES)
Burman, Lars G.
RESUMO
A penetration barrier operating outside the periplasmic enzyme penicillinase was studied in an ampicillin-resistant mutant of Escherichia coli K-12. Growth in the presence of lysozyme and sublethal concentrations of ampicillin partially opened the barrier. This could be recorded as an increased penetration of penicillin G, sodium cholate, and rifampin to their respective targets. Brief treatments with tris(hydroxymethyl)aminomethane-ethylenediaminetetraacetic acid and sodium cholate effectively impaired the barrier against penicillin and also caused leakage of penicillinase. Wild-type E. coli K-12, Proteus mirabilis, and Pseudomonas aeruginosa also showed an increased sensitivity to cholate after treatment with penicillins. Electron micrographs showed that lysis by cholate was due to a distortion of the cytoplasmic membrane causing a leakage of protein and RNA from the cells to the medium. Physiological data indicated that the increased sensitivity to cholate induced by growth in the presence of ampicillin or lysozyme was due to effects upon the murein. This was supported by measurement of the incorporation of 3H-diaminopimelic acid. These results indicate that the murein sacculus either is a part of the penetration barrier or is responsible for holding the structure of the outer membrane together.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=251572Documentos Relacionados
- Outer membrane permeation of beta-lactam antibiotics in Escherichia coli, Proteus mirabilis, and Enterobacter cloacae.
- Cloning, and expression in Escherichia coli K-12, of the chromosomal hemolysin (phospholipase C) determinant of Pseudomonas aeruginosa.
- Bacteriophage Typing of Proteus mirabilis, Proteus vulgaris, and Proteus morganii
- Outer Penetration Barrier of Escherichia coli K-12: Kinetics of the Uptake of Gentian Violet by Wild Type and Envelope Mutants
- In vitro antibacterial activities of tosufloxacin against and uptake of tosufloxacin by outer membrane mutants of Escherichia coli, Proteus mirabilis, and Salmonella typhimurium.
