Lecture 19: Phages and Phage Therapy

Question 1

how many bacterial cells are in 1 teaspoon of seawater?

Answer 1

5 million

Question 2

how many bacteria cells are in 1 gram of soil?

Answer 2

10 million

Question 3

what bacteria are transferred to babies from breast milk?

Answer 3

bifidobacteria that help with gut health

Question 4

what 2 things make bacteria difficult pathogens?

Answer 4

fast growth and toxin production

Question 5

when was the last time an antibiotic class was discovered?

Answer 5

1987

Question 6

what is a bacteriophage?

Answer 6

viruses that infect bacteria

Question 7

how were bacteriophages discovered?

Answer 7

noticeable holes in bacterial lawns

Question 8

what are the 6 stages of a bacteriophage infection and life cycle?

Answer 8

1. phages attach and inject chromosome into bacteria
2. break down bacterial DNA
3. replicate phage chromosome in bacteria
4. express phage genes
5. assemble phages in bacteria
6. release phages via bacterial wall lysis

Question 9

what is an alternate bacteriophage replication method (lysogeny)?

Answer 9

integrating themselves into host DNA and replicating with the host each time the host itself replicates

Question 10

what is the name for bacteriophages that use the alternative method?

Answer 10

temperate phages

Question 11

why is it hard to run clinical trials for bacteriophages?

Answer 11

difficult to conduct a double blind trial that is specific to patients but still be personalised and have placebos