46-Intro to Medical Microbiology 2 Flashcards Preview

Immunology > 46-Intro to Medical Microbiology 2 > Flashcards

Flashcards in 46-Intro to Medical Microbiology 2 Deck (63)
1

What is a virus

Nucleic acid with protein coat
Can have a lipid envelope
Not alive, depend entirely on host cell
Not metabolically active
Smaller than bacteria

2

What is a bacteriophage

Virus that infect and replicate in bacteria

3

DNA in a virus

double stranded, replicates in nucleus

4

RNA in virus

Single stranded, replicate in cytoplasm
Can be positive or negative

5

Positive sense RNA

Ready for translation

6

Negative sense RNA

Requires complementary strand synthesis

7

Lipid envelope

On some viruses
Non enveloped. Viruses are particularly hardy like norovirus

8

virion

Individual virus particle

9

capsid

Proteins associated with nucleic acid

10

capsomers

Individual proteins making up capsid

11

Spike proteins

Specific binding or enzymatic functions
Emerging from capsid of naked virus or membrane of enveloped virus

12

HIV

Reverse transcriptase during replication

13

Shape of capsomers

Helical or spherical (icosahedral)

14

Virus life cycle at cell level

Adsorption
Penetration and uncaring
Synthesis
Assembly
release

15

Virus life cycle at organisms level

Attachment
Spread
Replication
Evasion
transmission

16

adsorption

Interactions between viral proteins and specific host proteins

Have particular tropism

17

Penetration and uncoating

Need to get through cytoplasmic membrane to cytoplasm/nucleus for replication
Enveloped-fuse membrane
Naked-lyse

18

Synthesis and replication

+sense RNA ready to translate
-sense RNA need to generate +sense first
DNA transcribe mRNA

19

Assembly of virions

Helical-capsid proteins form around nucleic acid
icosahedral- capsid assembles and nucleic acid threaded in

20

release

Enveloped-membrane budding
Naked-cell lysis

21

influenza

Enveloped negative sense RNA with 8 genome segments

22

Adsorption of flu

hemagluttinin binds sialic acids

23

Uncoating of flu

Membrane fusion

24

Synthesis of flu

Happens in nucleus, use RNA dependent RNA polymerase to make +mRNA, goes to cytoplasm to make proteins and -mRNA

25

Assembly and release of flu

Virus capsid buds out
Neuraminidase cleanse sialic acid to release virion

26

High mutation rate of RNA virus from RDRP

Help virus evade immunity by causing gradual changes in viral proteins

reason for revaccination every year!

27

Antigenic drift

Gradual changes in viral protiens

28

Antigenic shift

Large changes caused by:
Segmentation of genome
Infection of humans and animals
coinfections

Only type A influenza

29

Immunity to flu

Presence of antibodies against hemaglutanin and neuraminidase

30

sialic acids

Bind hemaglutanin
Human 2-6
Birds 2-3
Pigs 2-3 and 2-6: mixing vessels

31

Where do viruses grow

Cell culture

32

PCR

Diagnostics For DNA virus

33

Reverse transcriptase PCR

diagnosticsRNA virus

34

Serology

Detection of antibodies to virus

35

Viral latency

Viruses can cause lifelong infection
Herpes 1: oral ulcers
Herpes 2: genital ulcers
VZV: chicken pox/shingles

36

What does innate immunity detect

Nucleic acids
dsRNA: not normal, cells infected by RNA virus that have died
5'triphosphate viral ssRNA: generated during RNA virus replication, recognized by RIG-I

37

M2 protein

Made by flu virus, channel for acidification of virion
Lowers pH and is detected by NLRP3

38

NLRP3

cytosolic protein, detect damage and stimulate cytokine production and stimulate inflammation
Detect non self and damaged self

39

Type 1 interferons

Interfere with viral replication
Impair protein uncoating, replication, protein synthesis
Enhanced antigen presentation

40

What does innate immunity do after detection of virus

Type 1 interferon
Programmed cell death
Activation of neighboring immune cells

41

virulence factors

Specific traits that permit evasion of host immunity

42

Virulence factors in flue

hemagglutinin that permit binding and uptake into respiratory cells
Ability to uncoat
Antigenic shift and drift

43

Epstein Barr virus

Mononucleosis
Herpes virus that transforms infected B lymphocytes into long lived cells (prevent cell death)

44

Virus pathology

Tissue damage and illness due to host response

Too little=uncontrolled replication
Too robust=excessive inflammation and organ damage

45

yeast

Single celled
Round or oval
Reproduce by budding
Candida

46

molds

multicellular
Form hyphae and Candida
Skin infections

47

dimorphic

Switch between yeast and mold

48

Fungi reproduction

asexually and form conidia (spores)

49

fungi

eukaryotes
capsule to inhibit phagocytosis
cell wall
Cell membrane

50

cell wall components in fungus

chitins, glucans, mannins

B-D-glucan syntheses is target for antifungals

51

Cell membrane components in fungus

ergosterol and sterols

Targets for antifungals

52

toxin production from fungus

alatoxicosis from contaminated food
Hypersensitivity/allergy

53

Infection from fungus

Superficial
Cutaneous:tinea pedis
Subcutaneous
Systemic: opportunistic, endemic mycosis

54

Candidiasis

Yeast
Common:C. albicans
Human commensal
Form pseudohyphae to permit survival
Opportunistic-diabetes, antibiotics, ill, neutrophils deficiency

55

Endemic mycoses
histoplasmosis

dimorphic
NOT commensals
In soil in the Midwest
Ingested by macrophages and grow within them

56

Targets of antifungals

Mannans
B-D-glucan
ergosterol

57

parasites

Protozoa
worms

58

protozoa

Single celled
Amebic, ciliated, flagellated, nonmotile

59

malaria

Parasite of red blood cells and liver cells

60

Worms (helminthes)

Nematodes (roundworms)
flatworms cestodes (tapeworms), trematodes (flukes)

61

schistosomiasis

Human interacts with cercariae, adult flukes, eggs
Disease caused by chronic inflammation and immune response to eggs laid by females

62

Immune response to helminths

Type TH2, eosinophilic inflammation and IgE
Resembles inflammation seen in allergies

63

Disease equation

Organism inoculum # * virulence
___________
Host defense