Toxins Flashcards
Define virulence
Degree of pathogenicity–capability of causing disease in a “normal host”
What’s the incubation period?
Time from infection to showing signs of disease
What are the properties of a successful pathogen?
Enter correct site in host
Adhere to specific host tissue
Resist host defenses
Damage host
Mechanisms of pathogenesis
Invasive (enters and grows in host)
Toxigenic
What kind of bacteria make exotoxins?
Both gram positive and negative
Are bacterial exotoxins immunogenic?
Yes, Made into a “toxoid” by chemical means for a vaccine
Are exotoxins involved in fever?
No
What classes of toxins are there?
Act on a receptor
Make pores in host cell membrane
A/B toxins
Type III and IV-syringe
What is the structure of an AB toxin?
Catalytic part, host cell binding part
What does the Diptheria toxin and Psuedomonas aeruginosa exotoxin A do?
ADP-ribosylates EF2–prevents protein synthesis
What does the botulinum toxin and tetanus toxin do?
Act as protease of SNAREs
What do large Clostridium dificile toxins do?
Glucosylate Rho proteins, which terminate transcription
What do Shiga toxins do?
Deadenylate adenine on RNA
What is diphteria toxin useful for?
Diptheria vaccine
Carrier in conjugate vaccines (ex. Hib)
Where do Corynebacterium diphteheriae infect and what is the mechanism of pathogenesis?
Upper respiratory tract, doesn’t require the toxin to start an infection. But when do get lysogenized by beta phage, make toxins that ADP ribosylates EF2. Then you get disease in the heart, liver, lung, nervous system.