• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

Card Range To Study

through

image

Play button

image

Play button

image

Progress

1/17

Click to flip

Use LEFT and RIGHT arrow keys to navigate between flashcards;

Use UP and DOWN arrow keys to flip the card;

H to show hint;

A reads text to speech;

17 Cards in this Set

  • Front
  • Back

In what ways are pathogens able to avoid being destroyed by a host

- hiding within a host cell


- avoiding through complement system proteins


- avoiding destruction from phagocytosis


- avoiding antibodies


- damaging the host

How can a pathogen avoid being englufed by phagocytes

- prevent encounters with phagocytes


- c5a peptidase - degrades c5a


- membrane damaging toxin - kill phagocyte


- avoid recognition and attachment


- capsules - interfere with opsonzation


- M protein - inactivates c3b


- fc receptors - bind to Fc region of antibodies


- surviving inside phagocyte


- escape phagosome


- prevent phagosome lysosome fusion


- survive within phagolysosome

How can a pathogen avoid antibodies

- IgA protease - cleaves IgA molecules


- Antigenic variation - changing structure of surface antigens


- mimicking host molecules - pretending to be host cell

Differentiate between endotoxin and exotoxin

- exotoxins - gram positive or negative, protein, potent, heat inactivated


- endotoxins - gram negative only, Lipid A, localized amounts yield mild response, systemic can be deadly, heat stable

what are some damaging effects of immune response

- inflamation - phagocytes can release toxic products


- adaptive immunity - immune (antigen-antibody) complexes can form and settle into body activating complement system


- cross reactive antibodies - bind to host tissue, autoimmune response

How are viruses able to avoid immune response

- avoiding effects of interferons - block expression of host genes or activation of enzymes


- avoiding antibodies


- move cell to cell or cause cell fusion


- motify surface antigen


- use antibodies to facilitate macrophage uptake


- regulating host cells death - block or present conterfit MHC class I molecule

Differentiate between artificial and natural active and passive immunity

- natural active - infection by bacteria


- artificial active - immune response after vaccination


- natural passive - antibodies from mother


- artificial passive - antibodies from other people or animals in vaccination

Types of inactivated vaccines

- inactivated whole agent vaccines


- toxoid


- subunit - consist of key protein or antigen


- recombinant - subunit made from genetically engineered microorganism


- VLP (virus-like particle) - empty capsid made from genetically engineer microorganism


- conjugate - polysaccharides + proteins

Seronegative, Seropositive, Seroconversion

- Seronegative - individual not yet exposed to antigen


- Seropositive - individual exposed to antigen


- seroconversion - process of producing antibodies, takes 7 - 10 days

Bacteriostatic vs bactericidal

- -static - inhibits bacterial growth, hosts defenses still need to kill bacteria


- -cidal - kill bacteria

What causes some antimicrobials to differ in the body

- only some can cross blood stream into CSF


- some affected by low pH, must be injected


- length of half life dictates frequency


- kidney or liver disfunction can differ

What causes resistance to antimicrobial drugs

- innate resistance - lacking cell wall, thick outer membrane of gram-negative bacteria


- aquired resistance - spontaneous mutation (combination therapy prevents), horizontal gene transfer (through R plasmids

Antibacterial drugs that inhibit cell wall synthesis

- penicillins, vancomicin


- B-lactam ring competetively inhibits enzymes that form peptide bridges between glycan chains


- side chains modified to create derivatives


- natural, penicillinase- resistant, broad spectrum, extended spectrum, + B-lactamase inhibitor



bacterial drugs that inhibit protein synthesis

- exploit difference in prokaryote ribosomes (70s 50s+30s)


- tetracyclines - block tRNA


- Macrolides - prevent continuation of protein synthesis

antibacterial drugs that inhibit nucleic acid synthesis

- fluoroquinolones cause strands to unwind


- rifamycins block rna polymerase

antibacterial drugs that interfere with metabolic pathways

- folate inhibitors - inhibit synthesis of folic acid


- sulfonamides, trimethoprin

MIC determination

- MIC (minimum inhibitory concentration) is lowest concentration that prevents growth


- Kirby- Bauer disc diffusion test


- MBC lowest concentration that kills 99.9% of bacteria in vitro