Host-Microbe Interactions Flashcards Preview

Disease & Defense - Unit 2 > Host-Microbe Interactions > Flashcards

Flashcards in Host-Microbe Interactions Deck (25):
1

Infection defintion

process by which a microbe enters into a relationship w/host; may or may not cause disease

2

Infectious disease definition and types

diease cause by an infection with a microbe; communicable or non-communicalble

3

Pathogenicity definition and types

the ability to cause disease; frank=in normal hosts vs. opportunistic=compromised hosts

4

Virulence definition

degree of pathogenicity; high virulence = ability to cause disease in small numbers

5

Koch's postulates (Microbes & Disease)

1. specific microbes w/in lesion 2. isolate/grow microbes in vitro 3. inject cultured microbes into animals-->reproduce disease 4. specific microbes w/in lesions of diseased animals

6

Major stages of all infectious diseases

1. Encounter 2. Entry 3. Spread 4. Multiplication 5. Damage 6. Outcome

7

Encounter stage of infection characteristics

how agent meets host: route of infection? infectious dose?

8

Entry stage of infection characteristics

how agent enters host: a. colonization of body surfaces b. adherence

9

Spread stage of infection characteristics

how agent spreads from site of entry: spreading factors vs. walling-off

10

Multiplication stage of infection characteristics

how agent multiplies w/in host: grow faster than killed

11

Damage stage of infection characteristics

tissue damage and virulence factors: a. toxins, enzymes b. blocking defense mechanisms

12

Outcome stage of infection characteristics

domination by microbe OR host OR coexistance

13

Immune response to infectious agents that multiply inside tissue cells

Antibody production and kill infected cells

14

Immune response to infectious agents that multiply inside phagocytes

Activate phagocytes to resist infection via lymphokines generated by T cells and kill infected phagocytes

15

Immune response to infectious agents that multiply outside cells

Kill microbe extracellulary (complement-mediated lysis) or intracellularly (opsonized phagocytosis and killing); neutralize microbial toxins

16

Immune response to infectious agents that multiply outside cells & attach to body surfaces

Coat surfaces w/antibody (primarily secretory IgA); neutralize microbial toxins

17

Typical bacteria of normal flora on skin

1. Gram-positive cocci: Staphylcocci 2. Gram-positive rods: Corynebacteria & Propionobacterium acnes 3. Gram-negative cocci: Enteric bacilli 4. Gram-negative rods: none 5. others: none

18

Typical bacteria of normal flora in oropharynx

1. Gram-positive cocci: a-hemolytic Streptococci 2. Gram-positive rods: Corynebacteria 3. Gram-negative cocci: Neissaria 4. Gram-negative rods: Hsemophilus, Bacteroides 5. others: Mycoplasma Spirochetes

19

Typical bacteria of normal flora in large intestine

1. Gram-positive cocci: Enterococci 2. Gram-positive rods: Lactobacilli 3. Gram-negative cocci: none 4. Gram-negative rods: Enteric bacilli 5. others: none

20

Typical bacteria of normal flora in vagina

1. Gram-positive cocci: Streptococci 2. Gram-positive rods: Lactobacilli 3. Gram-negative cocci: noen 4. Gram-negative rods: Bacteroides 5. others:

21

Physiological importance of the microbiome (4)

1. effects of tissue/organ differentiation 2. production of vitamins by gut flora 3. biochemical conversions 4. Forces other pathogens to compete for colonization

22

Cholera mechanism of pathogenesis

toxin-mediated

23

Pneumococcal pneumonia mechanism of pathogenesis

acute inflammation caused by invasive, extracellular bacteria

24

Tuberculosis mechanism of pathogenesis

infection by a facultative intracellular bacterium

25

Rheumatic fever mechanism of pathogenesis

pathology mediated by an immune response