[Bacterial lysis by lysozyme].
0
Citation
0
Reference
10
Related Paper
Abstract:
We confirmed the previous reports of Fleming, Nakamura et al. on the inability of lysozyme to lyse Micrococcus lysodeikticus cells at an acidic pH (3.0 - 3.5). In these conditions, lysozyme binds to the mucopolysaccharides of the cell wall without showing any lytic activity; lysis occurs at very high rate when pH is raised at neutral values by adding alkaline solutions. Our results were obtained by monitoring bacterial cultures both in aqueous solutions and on agar plates.Keywords:
Lytic cycle
Micrococcus
Muramidase
Cite
Ralston, Doris J. (University of California, Berkeley). Staphylococcal sensitization: specific biological effects of phage K on the bacterial cell wall in lysis-from-without. J. Bacteriol. 85: 1185–1193. 1963.—Phage K, shown previously to sensitize staphylococcal-wall mucopeptide to the action of a phage-induced enzyme, virolysin, was found to act in a specific manner in that its sensitizing effects were restricted to chemical linkages affected by three staphylococcal lysins. These caused an immediate lysis, whereas egg-white lysozyme, which could also digest the wall mucopeptide, exerted variable effects, even when in the absence of phage it produced some lysis. Evidence was presented that the K 1 normal cell autolysin and the K phage virolysin could act synergistically with lysozyme on phage-sensitized cells, and that any effects observed with lysozyme were due to the simultaneous presence of trace amounts of these staphylococcal lysins. None of a series of lysozymelike agents from sea urchins, marine sepunculids, and from rabbit peritoneal histiocytes caused accelerated lysis of phage-sensitized cells, although like lysozyme they showed a slow lysis of phage-free living cells. Other enzymes which did not reduce the turbidity of sensitized cells included agents specific for intracellular components (proteins, lipids, nucleic acids), and enzymes, as decarboxylase, alkaline phosphatase, d -amino oxidase, and hyaluronidase. These results suggested that the main effects of the phage in sensitization were limited to areas of the cell wall involved in protection against the action of the staphylococcal lysins.
Lysin
Teichoic acid
Lysostaphin
Micrococcus
Muramidase
Alteromonas
Autolysin
Cite
Citations (12)
We confirmed the previous reports of Fleming, Nakamura et al. on the inability of lysozyme to lyse Micrococcus lysodeikticus cells at an acidic pH (3.0 - 3.5). In these conditions, lysozyme binds to the mucopolysaccharides of the cell wall without showing any lytic activity; lysis occurs at very high rate when pH is raised at neutral values by adding alkaline solutions. Our results were obtained by monitoring bacterial cultures both in aqueous solutions and on agar plates.
Lytic cycle
Micrococcus
Muramidase
Cite
Citations (0)
Permanent auto-plaque negative (AP-) colonies are rarely detectable in AP+ strains cultured on tryptone agar. However, two types of AP- strains can be isolated from AP+ strains that are maintained for one to four weeks on refrigerated tryptose agar slants. One type appears to be permanently non-lytic and non-inducible with antibiotics, while the second type is inducible (APi-) with demethylchlortetracycline and may revert to the lytic state spontaneously. In addition, all AP- strains exhibiting iridescent patches in the absence of visible lysis were found to be inducible auto-plaque producers. Comparative optical density measurements of AP+ cultures with their corresponding AP- strains indicated no significant differences in their growth rate in aerated broth, nor was lysis detectable by this method. However, all AP+ strains exhibited auto-plaque formation in broth-containing petri plates when allowed to grow as a spreading thin pellicle under static conditions. Biochemical and antibiotic sensitivity comparisons of AP- strains with their corresponding AP+ parent indicated no qualitative differences other than changes in pigmentation at 37°C. In addition, refrigeration of pigmented AP+ strains grown on tryptose agar lead to the appearance of pink pigmentation in many strains, whereas none of the stock AP- cultures ever exhibited this property.
Lytic cycle
Cite
Citations (2)
Lysin
Lytic cycle
Bacterial virus
Cite
Citations (390)
Lytic cycle
Strain (injury)
Cite
Citations (20)
Objectives: Phage-coded lysins, i.e. murein hydrolases, are enzymes that destroy the cell wall of bacteria. A rapid killing of Streptococcus pneumoniae in the nasopharynx of mice has been described recently using a phage-coded murein hydrolase (enzybiotic). The in vivo effects of a dose-ranging treatment, using either of the phage-coded lytic enzymes Cpl-1 lysozyme or the Pal amidase, have been investigated here in a murine sepsis model.
Lysin
Lytic cycle
Amidase
Autolysin
Phage therapy
Muramidase
Cite
Citations (205)
A lytic enzyme induced in Micrococcus lysodeikticus strain 1 by infection with N1 bacteriophage was purified 45- to 50-fold by ammonium sulfate precipitation, acid precipitation, and selective adsorption of contaminating proteins with calcium phosphate gel. The optimal p H for activity of the enzyme was 6.5 to 7.0. Maximal activity occurred at 45 to 50 C and at an ionic strength of 0.06. The enzyme had a limited specificity and lysed cell walls of M. lysodeikticus with the release of dinitrofluorobenzene reactive groups. Living cells were lysed in the absence of phage; however, the rate of lysis increased when phage was present in excess of 10 particles per bacterial cell. Young cells were most sensitive, and the sensitivity decreased to a minimum with stationary-phase cells. Acting synergistically, lysozyme and the N1-induced lysin caused lysis of cells which were resistant to either enzyme acting independently. The N1 lysin did not exhibit proteolytic activity.
Lytic cycle
Lysin
Micrococcus
Cite
Citations (10)
Hart, Beth A . (Cornell University, Ithaca, N.Y.), and Stanley A. Zahler . Lytic enzyme produced by Myxococcus xanthus . J. Bacteriol. 92: 1632–1637. 1966.—Strain FBa of Myxococcus xanthus releases into its culture medium an enzyme capable of lysing Micrococcus lysodeikticus cells and of releasing N -acetyl amino sugars from their cell walls. The lysin is stable at p H values near neutrality and at temperatures below 50 C. It lyses a number of bacterial species sensitive to egg-white lysozyme, and fails to lyse lysozyme-resistant species. Sensitivity of M. lysodeikticus cell walls to FBa lysin and to lysozyme is changed in a similar manner by addition and removal of O -acetyl groups. We describe methods for obtaining 190-fold purification of the lysin from culture filtrates, using acetone and ammonium sulfate precipitations and filtration through diethylaminoethyl cellulose. We also describe a gel filtration method for separating the lysin from a protease which is also produced by strain FBa.
Myxococcus xanthus
Lysin
Lytic cycle
Micrococcus
Protoplast
Strain (injury)
Cite
Citations (44)
Group B streptococci treated with cell wall synthesis inhibitors (penicillin or vancomycin) or by a variety of membrane-acting agents are sensitized to the lytic action of exogenous M1 muramidase. Muramidase without a sensitizing agent caused rupture of bacterial chains only, accompanied by the release of a small amount of cell wall peptidoglycan label and an increase of the number of colony-forming units. In combination with sensitizing agents the exogenous muramidase appeared to initiate hydrolysis of biosynthetically new peptidoglycan. Treatment of the cells with chloramphenicol or starvation for nutritionally required amino acids suppressed the rate of cell lysis and peptidoglycan hydrolysis during subsequent sensitization and muramidase treatment of the bacteria. Purified cell walls prepared from the amino acid starved cells were also hydrolyzed with a slower rate by muramidase. It is suggested that agents sensitizing the bacteria to the exogenous muramidase act by perturbing or removing some nonmurein components of the cell envelope which protect the peptidoglycan from the activity of exogenous enzyme. Agents increasing resistance against exogenous muramidase may also cause some alteration in peptidoglycan structure.
Muramidase
Lysin
Cell envelope
Teichoic acid
Lytic cycle
Cite
Citations (3)
Lytic cycle
Muramidase
Lysin
Cite
Citations (47)