Lecture 13 Flashcards
How do bacteria invade human body
-Through mucus membranes (respiratory and garstrointestinal tracts, urinary tract and genital openings)
-Non intact skin (bites, wounds, injections…)
How do bacterial pathogens damage host cells?
- Invasion
- Toxins
What is invasion
Ability to spread to other loc in host by invading cells or tissues. Atp that signs of illness and disease occur
what are Toxins
Very specific virulent factor produced by bacterial pathogens, poisonous substances to host
What is toxigenicity
Organism’s ability to make toxins
Two categories of toxins
Endotoxins and exotoxins
Exotoxins
Toxin secreted by microorganism into surrounding enviro
Endotoxin
Toxin release by microorganism into environment when it dies, it’s part of cell wall
Impacts to metabolic pathways in eukaryote host by bacterial toxins
- Damage cell membrane
- Disrupt prot synthesis
- Inhibiting function of nervous syst
- Inhibiting activation of host immune syst
Some pathogens
Gonorrhea, lyme disease, strep throat, tuberculosis, tetanus
What are antibiotics
Drugs to treat infections caused by bacteria
What is zone of inhibition (ZOI)
Clear zone surrounding antimicrobial agent, complete absence of bacteria
What is a bacterial lawn
Dense and uniform layer of bacteria on agar plate
What is selective toxicity
When agents affect pathogens and not host (by interacting with structures not present in/diff from host)
Antibiotic modes of action
- Cell wall synthesis
- Cell membrane function
- Metabolic reaction
- Prot synthesis
- Dna synthesis