Bacteriophage Lana Evers

What is a bacteriophage  A bacteriophage, also known as a phage, is a bacterial virus that attach to their specific hosts and kill them by internal replication and bacterial lysis.

History of phage Bacteriophage inhabited Earth about 3-5 billion years ago The existence of bacteriophage was not known about until the early part of the 20 th century Was first identified by Frederick Twort and Felix d’Herelle These two scientists name them this bacteriophages from the Greek word phago which means to eat or devour At that time, bacteriophage were considered a powerful cure for bacterial infections and were therapeutically utilized throughout the world during the pre-antibiotic era Bacteriophage inhabited Earth about 3-5 billion years ago The existence of bacteriophage was not known about until the early part of the 20 th century Was first identified by Frederick Twort and Felix d’Herelle These two scientists name them this bacteriophages from the Greek word phago which means to eat or devour At that time, bacteriophage were considered a powerful cure for bacterial infections and were therapeutically utilized throughout the world during the pre-antibiotic era

History of Phage There are no exact numbers however it is estimated that millions of people have been treated with various therapeutic phage preparations Bacteriophage naturally inhabit various parts of the human body – ie: mouth, skin, gastrointestinal tract, etc. Humans daily eat many foods containing phage There are no exact numbers however it is estimated that millions of people have been treated with various therapeutic phage preparations Bacteriophage naturally inhabit various parts of the human body – ie: mouth, skin, gastrointestinal tract, etc. Humans daily eat many foods containing phage

Applications of phage Gene therapy vehicles Alternatives to antibiotics The detection of pathogenic bacteria Tools for screening libraries of proteins, peptides or antibodies Gene therapy vehicles Alternatives to antibiotics The detection of pathogenic bacteria Tools for screening libraries of proteins, peptides or antibodies

What is Phage therapy  Phage therapy is the therapeutic use of bacteriophages to treat pathogenic bacterial infections.

History of phage therapy Widely used in the 1920’s and 30’s Large pharmaceutical companies sold products for treatment of Streptococcus and colon bacilli infections Discovery of antibiotics led to the abandonment of phage therapy products in America and most of western Europe Phage therapy treatment and research continued in the Soviet Union Widely used in the 1920’s and 30’s Large pharmaceutical companies sold products for treatment of Streptococcus and colon bacilli infections Discovery of antibiotics led to the abandonment of phage therapy products in America and most of western Europe Phage therapy treatment and research continued in the Soviet Union

How does phage therapy work? Attach themselves to a victim using its tail fibres After this, the process is different for each phage type The aim: to get their genetic material, located in the head, inside the bacterium Attach themselves to a victim using its tail fibres After this, the process is different for each phage type The aim: to get their genetic material, located in the head, inside the bacterium

How it works: t4 1. Phage’s DNA pushes through tube into cell 2.Takes control 3.Brutally stops many vital functions 4.Forces cell to churn out new virus components – head, tails, fibres 5.Enzymes dissolve the wall of bacterium from the inside 1. Phage’s DNA pushes through tube into cell 2.Takes control 3.Brutally stops many vital functions 4.Forces cell to churn out new virus components – head, tails, fibres 5.Enzymes dissolve the wall of bacterium from the inside

Phage therapy vs. antibiotics

Phage therapy

Drawbacks of phage therapy Proponents of phage therapy never succeeded in producing formal proof of efficacy in human treatment This makes definitive conclusions difficult Proponents of phage therapy never succeeded in producing formal proof of efficacy in human treatment This makes definitive conclusions difficult

Methods and purposes

Titrations 1.Pick a plaque from a countable web plate 2.Create 10-fold titrations Why? To obtain a titer 1.Pick a plaque from a countable web plate 2.Create 10-fold titrations Why? To obtain a titer

Ten Plate infections 1.Infect ten plates to see which one webs out the best Why? To see which titration webs out 1.Infect ten plates to see which one webs out the best Why? To see which titration webs out

Spot test 1.Make a grid with 10 spots for – one for each dilution 2.Put a single drop onto each corresponding spot Why? To see which dilutions give us plaques and contain phage 1.Make a grid with 10 spots for – one for each dilution 2.Put a single drop onto each corresponding spot Why? To see which dilutions give us plaques and contain phage

Streak plate 1.Pick a plaque 2.Streak across three labeled sections Why? To see if the plaque contains phage 1.Pick a plaque 2.Streak across three labeled sections Why? To see if the plaque contains phage

Flood plates 1.Add phage buffer to webbed plates 2.Obtain High Titer Lysate (HTL) Why? To obtain an HTL 1.Add phage buffer to webbed plates 2.Obtain High Titer Lysate (HTL) Why? To obtain an HTL

Restrict & analyze DNA 1.Digest DNA with restriction enzymes 2.Electrophorese 3.Obtain gel image Why? Compare restrictions with other mycobacteria's 1.Digest DNA with restriction enzymes 2.Electrophorese 3.Obtain gel image Why? Compare restrictions with other mycobacteria's

My phage - ilsa

Results Yield – ug/mL Titer – x10^9 Size: Head – about 40nm Tail- about 70nm Yield – ug/mL Titer – x10^9 Size: Head – about 40nm Tail- about 70nm

Works cited