scholarly journals More than a hole: the holin lethal function may be required to fully sensitize bacteria to the lytic action of canonical endolysins

2016 ◽  
Vol 102 (1) ◽  
pp. 92-106 ◽  
Author(s):  
Sofia Fernandes ◽  
Carlos São-José
Keyword(s):  
Lytic Action

In Vitro Studies on the Mechanism of the Antifibrino-lytic Action of E-Aminocaproic Acid (EACA)

1968 ◽  
Vol 19 (03/04) ◽  
pp. 584-592 ◽  
Author(s):  
Hanna Lukasiewicz ◽  
S Niewiarowski
Keyword(s):  
Aminocaproic Acid ◽  
Test Tube ◽  
In Vitro Studies ◽  
Lytic Action ◽  
Human Plasminogen ◽  
Experimental Findings ◽  
Fibrin Clots

Summary and Conclusion1. It has been found that EACA does not inhibit activation of human plasminogen into plasmin by SK and UK in a concentration of 5 × 10–2 M. The activation of bovine plasminogen by SK and UK is inhibited by this concentration of EACA but not by a lower one.2. EACA in concentrations of 1,5 × 10–1 – 10–4 M does not inhibit casein proteolysis by plasmin. The proteolysis of fibrinogen and fibrin measured by the release of TCA soluble tyrosine is inhibited by EACA in concentrations of 1,5 × 10–1 – 10–2 M.3. The lysis of non-stabilized clots by plasmin measured in a test tube was inhibited by an EACA concentration of 5 × 10–3 – 5 × 10–4 M. The lysis of stabilized clots by plasmin was inhibited by an EACA concentration of 10–5 M.4. On the basis of experimental findings and data given in literature the authors postulate that the mechanism of the antifibrinolytic effects of EACA consists mainly in a modification of plasmin action on fibrin. These effects are dependent on the structure of the fibrin clots.

Lysozyme and Lipase Alter Unfrozen and Frozen/Thawed Cells of Listeria monocytogenes

1992 ◽  
Vol 55 (10) ◽  
pp. 777-781 ◽  
Author(s):  
SOUZAN E. EL-KEST ◽  
ELMER H. MARTH
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Listeria Monocytogenes ◽  
Frozen Storage ◽  
Lytic Action ◽  
Transmission Electron ◽  
Cellular Lysis

Unfrozen and frozen/thawed cells of Listeria monocytogenes strains Scott A, V7, and California were treated with lipase and/or lysozyme. Cells of strain Scott A were more susceptible to the lytic action of lysozyme than were cells of strains V7 and California. Treatment of unfrozen cells with lipase before exposure to lysozyme enhanced cellular lysis. This also was true for cells held frozen for up to 6 weeks before they were thawed and treated with enzymes. Some variation existed among strains of L. monocytogenes in their susceptibility to effects of lysozyme. Frozen storage of cells of all three strains increased their susceptibility to lysis by lipase, and this was related inversely with the percentage of cells that survived freezing and frozen storage. Transmission electron microscopy showed some enzyme-treated cells formed protoplasts.

NUTRITION AND METABOLISM OF MARINE BACTERIA: XI. SOME CHARACTERISTICS OF THE LYTIC PHENOMENON

1962 ◽  
Vol 8 (6) ◽  
pp. 883-896 ◽  
Author(s):  
Robert A. MacLeod ◽  
Tibor I. Matula
Keyword(s):  
Cell Wall ◽  
Marine Bacteria ◽  
Divalent Cations ◽  
Morphological Characteristics ◽  
Bacterial Cells ◽  
Whole Cells ◽  
Lytic Action ◽  
Absorbing Materials ◽  
Sulphate Salts ◽  
Osmotic Effects

Five marine bacteria examined were found to differ considerably in lytic susceptibility. Some lysed completely below 0.15 M NaCl while suspensions of others contained some whole cells at 0.025 M NaCl. In general NaCl and LiCl were more effective than KCl or NH4Cl in protecting against lysis and the loss of ultraviolet-absorbing materials from the cells. KCl could spare the requirement for NaCl to prevent lysis. Mg++ and other divalent cations at 0.05 M or less completely prevented lysis of all but one of the organisms. Sulphate salts stabilized the cell suspensions better on incubation than did chlorides for four of the organisms. For the fifth the reverse was true. The lytic action of ethanol and glycerol could be prevented by NaCl or sucrose. The concentrations of the latter required to prevent lysis remained unchanged when ethanol or glycerol was included in the suspending medium. Cells washed essentially free of electrolytes with 0.5 M sucrose retained their morphological characteristics. The observations are considered in relation to the distinction between marine bacteria, halophiles, and terrestrial bacteria and to current theories of the mechanism of lysis of bacterial cells. The results are not consistent with the hypotheses either that primarily osmotic effects are involved or that electrolytes are required to maintain the cell wall.

scholarly journals Efficient plasmid transduction toStaphylococcus aureusstrains insensitive to the lytic action of transducing phage

2016 ◽  
Vol 363 (19) ◽  
pp. fnw211 ◽  
Author(s):  
Ivana Mašlaňová ◽  
Sabina Stříbná ◽  
Jiří Doškař ◽  
Roman Pantůček
Keyword(s):  
Lytic Action ◽  
Plasmid Transduction

scholarly journals Further observations on a bacteriolytic element found in tissues and secretions

1922 ◽  
Vol 94 (658) ◽  
pp. 142-151 ◽  
Keyword(s):  
Agar Plate ◽  
The Body ◽  
Zone Of Inhibition ◽  
Lytic Action ◽  
Inhibition Of Growth ◽  
Previous Communication ◽  
Micrococcus Lysodeikticus

In a previous communication one of us* (A. F.) described an anti-bacterial substance (lysozyme) normally present in the tissues and secretions of the body. Further experiments have been done in connection with this substance, and some of the results obtained are here described. Development of Strains of Bacteria Resistant to Lysozyme . It was shown in the earlier communication that lysozyme existed in the tissues and secretions affecting many microbes, but that one type of coccus, which was called the Micrococcus lysodeikticus , was especially suitable for experimental purposes with this lytic substance as it was particularly susceptible to the lytic action, so that if a small quantity of lysozyme-containing material was embedded deep in the centre of an agar plate, and then the whole surface of the plate was thickly planted with this microbe, there was inhibition of growth of the coccus for a considerable area around the embedded tissue. It was found, however, that if these culture plates were kept for two or three weeks there developed in the zone of inhibition a few isolated colonies of a microbe which appeared to be identical with M. lysodeikticus . The appearance of such a plate is shown in fig. 1 (Plate 6).

scholarly journals STUDIES CONCERNING THE RELATIONSHIP BETWEEN PNEUMOCOCCI AND STREPTOCOCCI

1927 ◽  
Vol 45 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Hobart A. Reimann
Keyword(s):  
Streptococcus Viridans ◽  
Freezing And Thawing ◽  
Lytic Action ◽  
Immunological Reactions ◽  
The Relationship

Morgenroth and his collaborators grew pneumococci in a medium containing optochin and derived variant forms of bacteria therefrom which were considered to be streptococci of the viridans group. We have repeated these experiments and have also derived variant forms. These atypical races, however, we have found to be identical with the R form of pneumococci which have been obtained by various other methods. That these R cultures are still pneumococci and do not belong in the Streptococcus viridans group is supported by the following observations: 1. These strains are not bile-insoluble, but are more resistant to the lytic action of this agent than are type-specific pneumococci. 2. R strains behave like pneumococci and not like streptococci in the readiness with which cultures spontaneously autolyze and saline suspensions disintegrate during freezing and thawing. 3. Immunological reactions of the variant pneumococci derived by Morgenroth's method are identical with the immunological reactions of R forms of pneumococci derived by various other means. The observations of Morgenroth and his associates in regard to the transformation of Streptococcus hæmolyticus into Streptococcus viridans by treatment with rivanol could not be repeated in this laboratory. No explanation is at hand for our failure to produce the change. It is of course possible that none of the twenty-six strains tested had suitable tendencies to variation or that the technic or reagents employed varied from those of Morgenroth.

Lytic action of strepzymes from micromonospora AS

1965 ◽  
Vol 51 (2) ◽  
pp. 156-167 ◽  
Author(s):  
S. Gascon ◽  
A. G. Ochoa ◽  
M. Novaes ◽  
J. R. Villanueva
Keyword(s):  
Lytic Action
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