information

Whoever comes in this website may find a hint

Phage therapy is influenced by:

Phage therapy is influenced by:

Country :
the epidemiological situation is different from country to country in terms of circulating bacteria and bacteriophages. Example: a lytic phages from Italy may be no active on the same bacteria (genus and species) isolated from another country and vice versa.
Chronolability
Mutation rate
Phenotypical delay
Phage cocktail
My point of view

From Wikipedia


If the target host* of a phage therapy treatment is not
an animal the term "
biocontrol" (as in phage-mediated biocontrol of bacteria) is usually employed, rather than "phage therapy".

"In silico"

From:"Genomics,Proteomics and Clinical Bacteriology", N.Woodford and Alan P.Johnson

Phrase that emphasizes the fact that many molecular biologists spend increasing amounts of their time in front of a computer screen, generating hypotheses that can subsequently be tested and (hopefully) confirmed in the laboratory.

Saturday, 28 June 2014

“Lysis from within”, “Lysis from without”and Lysogenic bacteriophages


Bacteriophages that can only follow the lytic cycle are known as virulent bacteriophages. Lysis of the host bacterial cell can occur as a result of two possible mechanisms indicated below:

"Lysis from within”

In this case, lysis of the host cell occurs as a result of phage replication. The genetic material is the only component of the virion that enters into the host cell, which may occur through injection (bacteriophages with contractile tails) or following the enzymatic breakage of the cell wall. In both cases, the pore generated in the membrane will affect its electric potential, although this harm is easily repaired. Once inside the cell, the genetic material of the bacteriophage is replicated hundreds of times, the coat proteins are synthesized and new particles are assembled that will constitute the viral progeny (usually between several tens and a few hundreds per infected cell). Release of the progeny is the consequence of the collaborative action of the holin, a hydrophobic polypeptide that forms pores in the cell membrane, through which the lysin (a muramidase) reaches the cell wall, thus provoking the lysis of the host-cell.


"Lysis from without"

In this case, lysis of the host cell occurs in the absence of phage replication. This happens when a sufficiently high number of phages particles adhere to the cell, and lyse it through alteration of the membrane electric potential, and/or the activity of cell wall degrading enzymes.


Lysogenic bacteriophages


Some dsDNA bacteriophages, however, have the capacity to synthesize a repressor protein that silences most bacteriophage genes and results in abortion of the lytic cycle. Under these circumstances the bacteriophage DNA (the prophage) synchronizes its replication to that of the host to be inherited by its offspring.

In most cases this is brought about through integration of the bacteriophage DNA into the host genome via site-specific recombination. This alternative method of bacteriophage propagation is called the lysogenic cycle and the bacteriophages able to pursue it are known as temperate.