Bacteriophages

Question 1

What does Bacteriophages mean?

Answer 1

(phagos – eating)

Question 2

Morphology

Answer 2

high diversity

groups: A-G
•nucleic acid: dsDNA, ssDNA, dsRNA, ssRNA
•symmetry: binal, icosahedral, helical, pleomorphic

Question 3

Effect on bacteria

Answer 3

Lytic effect on bacteria
→ potential antibacterial treatment of infected vertebrate hosts, if antibiotics are not applicable
•Problems with the application (antigens)
•Promising experimental results

Question 4

Biological properties

Answer 4

penetration – special routes 
species specificity
•phage typing – Tb phage
•phage titer increase – Salmonella typhi in drinking water
→ detection with M3 phag

lysogen infection – temperate phage (prophage)
→ phage induction: lytic infection – virulent or vegetative phage

lysogen conversion – changed bacterial properties
→ i.e. toxin production – β phage

transduction – gene transfer between bacteria

Question 5

Generas:

Answer 5

Several

Question 6

Some important phages:

Answer 6

• Tbilissi (Tb) phage – Brucella typing
• T4 phage – Escherichia coli – big, complicated phage
• β phage – Corynebacterium diphtheriae conversion → diphtheria
• λ phage – Escherichia coli – genetic model virus, DNA marker •φX174 phage – Escherichia coli – the smallest known virus (12 nm)