Bacteriophage Lana Evers What is a bacteriophage A

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

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

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

What is Phage therapy is 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

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

How it works: t 4 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

Methods and purposes

Titrations 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

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

Streak plate 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

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

My phage - ilsa

Results Yield – 0. 0035 ug/m. L Titer – 3. 0445 x 10^9 Size: Head – about 40 nm Tail- about 70 nm

Works cited • www. phagetherapycenter. com • https: //www. youtube. com/watch? v=F 5 xsi 40 S 2 Z 0 • www. thenakedscientists. com