45-Intro to Medical Microbiology 1 Flashcards Preview

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Flashcards in 45-Intro to Medical Microbiology 1 Deck (52)
1

5 obligatory capabilities of medically important microbes

Attachment
Spread
Replication
Evasion of host defenses
Transmission/shedding

2

colonize

Exists without causing disease

3

infection

Organism is causing disease

4

commensal

Live on/in without causing disease

5

parasite

Live on/in and causes illness

6

reservoir

Where organisms is maintained (human, environment, animals)

7

Gram stain

Used to see shape, arrangement, and color

8

Gram positive

Thick peptidoglycan, hold violet stain, appear dark blue

9

Gram negative

thin peptidoglycan, lose violet stain, appear pink

10

Shape of bacteria

cocci-round
Bacillus-rod
Spirochete-spiral

11

Arrangement of bacgteria

Cluster
Chain
diplo

12

peptidoglycan made of what

Interlinked polysaccharide and peptide chains cross linked with NAM and NAG

Target for B-lactam (penicillin)

13

Function of peptidoglycan

structure and rigidity of bacteria

14

porins

Gram negative
Passage of nutrients and antibiotics

15

lipopolysaccharides

Gram negative
Caused endotoxin and illness
Recognized by MAMPs

16

Beta lactamases

Produced by bacteria to hydrolyzed B-lactam antibiotics

Also used to kill other bacteria

17

Bacterial DNA

prokaryote
1-10 megabases
Distinct transmissible DNA units (plasmids, transposons, bacteriophages)

18

Bacterial DNA replication

Requires DNA polymerase
DNA gyrate and topoisomerase for unwinding-targeted by fluoriquinolones

19

Eukaryotic ribosomes

80S (60S and 40S)

20

Bacteria ribosomes

70S (50S and 30S)

21

Growth curve depends on

nutrient availability, pH, bacterial concentration

22

When are toxins produced

Stationary phase

23

What is a biofilm

Produced by bacteria to protect from immune system

24

Phases of growth curve

Lag
Log/exponential
Stationary
death

25

What are spores

Formed from bacteria
Highly resistant to drying, heat, chemicals
Can regenerate when conditions permit

26

obligate aerobes

require oxygen for survival
TB

27

anaerobes

Killed by oxygen
Colon bacteria

28

Facultative anaerobes

grow aerobically or anaerobically

29

microaerophilic

grow best at low oxygen

30

Innate immunity

Respond to foreign material
Genetically encoded from birth

Barriers-skin and mucosa
Preformed proteins-complement system, natural antibodies
phagocytes-neutrophils, macrophages

31

microbe associated molecular pattern MAMPs

Innate immune system recognizes these non self
Pattern recognition receptors

32

Damage associated molecular pattern DAMPs

Body senses signs of injury

33

Role of phagocytes

confine, kill and clear invaders

34

pathogen

Organisms that make us ill
Hard for organism to usually live on us
Pathogens have factors to evade host defense

35

Virulence factor

Factors that permit infection

36

Equation for a disease

Organisms inoculum * virulence
________________
Host defense

37

Adaptive immune system

Once exposed to substance
generate specific cells and antibodies to respond to it and prevent disease

38

Coat and kill microbes

Antibodies, complement proteins, enzymes

39

opsonization

Coat particle with proteins
Make it easier for host to phagocyte and ingest

40

Most important opsonic proteins

Antibodies and complement

41

Examples of virulence factors

Escape phagosome
Alter membrane to prevent lysosome fusion
Capsule to block complement and antibody binding
Toxins-disrupt cell function
Enzymes-protect against microbicidal

42

lipid membranes of + vs -

+ cytoplasmic
- cytoplasmic and outer membrane

Gram - harder to access for antibiotics

43

Unique features of + vs -

+ teichoic and lipteichoic acids
- lipopolysaccharide

Important MAMPs sensed by innate immune system

44

Shared structures of + and -

flagella, pili, membrane proteins

45

capsule

Surface polysaccharide
Inhibit ingestion by phagocytes

46

toxins

Staph aureus
enterotoxigenic E coli

47

secretion

Gram - require specific structures to secrete

48

sense extracellular infections

Toll like receptor

49

Sense intracellular infection

Nod like receptors

50

mycobacteria

Acid fast
Waxy wall, mycolic acid, and LAM make it hard to stain
TB

51

Acquisition of microbes

Another person
Own microbiota
Animal
Environment

52

Cononizing

Bacteria can start as colonizers and then cause disease
Or never colonize and still cause disease