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Flashcards in Micro Summary: Virulence Factors Deck (43):
1

Bacteriodes: Bacilus, Prevotella, Porphoryngeus

LPS, capsule, enterotoxin

2

Histotoxic Clostridia: C. perfringens, C. septicum

Exotoxins, α toxin

3

C. tetani

Tetanus toxin

4

C. botulism

Exotoxin (neurotoxin), Botulinum toxin (type A most serious, persists the longest in the neuron), Spores: heat-resistant (toxin is heat-sensitive)

5

C. difficile

Toxins A & B: enterotoxins, render intestinal epithelial cells nonfunctional & leaky, chemoattractants for neutrophils, provoke inflammation, Binary toxin: causes cytoskeletal effects

6

Campylobacter jejuni

Adhesions, LPS

7

Haemophilus influenzae

Capsules, Hib, LOS, IgA, obtain iron from transferrin

8

Mycoplasma pneumoniae

Adhesins, CARDS toxin, peroxides, inflammation

9

Escherichia coli

(1) Fimbrial & afimbrial adhesins: All produce a common (type 1) pili that attach to mannose receptors, Pathogenic E. coli have a unique pili (CFA for ETEC) to bind unoccupied receptors; (2) Iron acquisition: Produce siderophores w/ high affinity for iron; (3) Toxins: Endotoxin (LPS): outer membrane, Hemolysin: pyelonephritis, Heat-stable enterotoxin: increases cGMP, Heat-labile enterotoxin: increases cAMP, Shiga toxin: inactivates ribosomes

10

Salmonella

LPS: inflammation, Type III secretion system & effectors: Inv/Spa (entry) & Spi/Ssa (survival in macrophages), Pho/PhoQ: controls gene expression, PagC & outer membrane proteins: resist antimicrobial peptides, Adhesins, Typhoid toxin: damages hot DNA, Vi antigen: capsular polysaccharide, Flagella

11

Shigella

LPS, Ipa proteins, Mxi-Spa TTSS needle, IcsA, IcsB, Shiga toxin

12

Yersinia pestis

LPS, TTSS, plasminogen activator

13

Rickettsia rickettsii

Direct actin reorganization (filopodia enhances spread), Phospholipases, proteases, and membrane peroxidation result in host cell damage, Energy parasites

14

Borrelia burgdorferi

Osps (surface lipoproteins, differentially expressed, important for attachment/adhesins)

15

Bacillus anthracis

Capsule, Exotoxins (Edema toxin, Lethal toxin)

16

Francisella tularensis

Capsule, FPI

17

Helicobacter pylori

Urease & flagella (for higher pH), VacA, cag pathogenicity island (type IV secretion system & CagA), LPD, & inflammation/urease

18

Staphylococcus aureus

Multiple adhesion molecules, exotoxins, cell wall components (LTA, peptidoglycan), exotoxins (hemolysins, enterotoxins, exfoliative epidemolytic scalded skin syndromes, toxic shock syndrome toxin), protein A, polysaccharide capsule, peptidoglycan, LTA, resistance molecules

19

Acinetobacter baumanii

Endotoxin

20

Neisseria meningitidis

*Capsule, outer membrane proteins, pili, LOS, IgA-protease, complement-binding proteins

21

Neisseria gonorrhoeae

Pili, Opa proteins, LOS

22

Streptococcus pyogenes

M protein, LTA, cell wall components: hyaluronic acid (disguise molecular mimicry), C5a peptidases (complement), exotoxins: hemolysisn, streptokinase steptodornase, hyaluronidase, erythrogenic toxin

23

Streptococcus pneumoniae

Adherence: neuraminidase, Immune evasion: IgA protease, Inflammation: LTA, Immune evasion: capsule, Defense damage: pneumolysin

24

Listeria monocytogenes

phagosome, a toxin (listeriolysin O; gene: hlyA) which breaks open the phagosome and allows the bacterium to enter the cytoplasm, an actin tail by actA which propels the microbe around the cell, and sometimes into a neighboring cell, allowing cell to cell spread without leaving the cell (eliminates exposure to antibodies)

25

Legionella pneumophila

Intracellular, (1) replication phase (abundant nutrients) & (2) transmission (limiting nutrients), Inhibition of phago-lysosome fusion by remodeling phagosome to look like the RER by recruiting host secretory vesicles from the ER, Type IV secretion system may allow rapid secretion of effector molecules to modulate phagosome and prevent fusion with lysosomes

26

Pseudomonas aeruginosa

exotoxin A: necrosis, endotoxin: shock, pili: adhesion, enzymes (proteases, elastase): tissue damage, leucocidin: inhibits/kills WBCs, phospholipase C: hemolysin, affects WBCs, capsule (slime layer/biofilms): antiphagocytic, contributes to cystic fibrosis, inferferes w/ antibiotic actio+K32n

27

Mycobacterium tuberculosis

mycolic acids, lipids, liparabinomannan (~LPS), cytolysin, adhesin/invasin genes, secretion systems (ESX loci), allow survival & replication of M. tuberculosis within macrophages using complement receptor

28

Mycobacterium leprae

lipid-rich outer "capsule" contains phenolic glycolipid 1 (PGL-1), acid fast, slow-growing, resides within macrophages & Schwann cells (tropism for peripheral nerves)

29

Corynebacterium diphtheria

Adhesins, diphtheria toxin: responsible for the disease, inhibits hot cell protein synthesis by ADP-ribosylating elongation factor 2

30

Vibrio cholera

Cholera toxin: causes increased cAMP levels in intestines --> fluid & electrolyte loss, Zonula occludens toxin (affects tight junctions) & accessory enterotoxin (forms ion channels),Toxin-coregulated pilus, biofilm production, other adhesins, & other colonization factors

31

Bordetella pertussis

adhesins: fliamentous hemagglutinin, pertussin toxin, pili, pertussis toxin: A-B exotoxin, increases cAMP, adenylate cyclase: increases cAMP, tracheal cytotoxin derived from peptidoglycan: kills ciliated cells, heat-labile toxin: local damage

32

Poliovirus

CNS spread, unenveloped for GI acid, 2A protein (inhibits protein translation), 2BC/3A protein (inhibits vesicle transport), 3C protease (inhibits transcription)

33

HBV

4 genes (surface, core, pol, X), chronic infection, HBsAG immune decoy

34

HCV

High mutation rate of viral RNA polymerase, protease

35

HSV

envelope: acquired from host, tegument: surrounds capsid, capsid: icosahedral, DNA genome: linear dsDNA, Viral DNA synthesis: maintain nucleotide pools in quiescent cells (thymidine kinase & ribonucleotide reductase), Control host cell function: shut-off protein synthesis and block apoptosis (UL41 & g34.5),Control host cell function: toxicity/apoptosis (ICP0), Immune regulation: block complement, antibody and Ag recognition (gE/gI, gC, & ICP47)

36

HPV

Enter and remain in latency in keratinocytes, Inactivation of E1 or E2 genes --> integration into host DNA --> up-regulation of E6 &E7 oncogenes --> transformation

37

Norovirus

Capsid

38

Rotavirus

Nonstructural protein (NSP4): enterotoxin

39

Adenovirus

Early genes hijack normal growth resources for viral replication, Immune evasion by blocking cell signaling (E3), Cell destruction (cytopathic effect) releases new virions

40

Hantavirus

Envelope glycoproteins

41

Rabies

Neuronal tropism, targets ACh receptor

42

EBV

Infects B cells or nasopharyngeal cells by CD-21(-like), receptor, Latency & immortalized human B cells

43

Influenza

Hemagglutinin (HA) protein: binds carbohydrates, causes fusion for entry into cell, releases viral RNA inside cell, Neurominidase: releases new viral particles to infect new cells, prevents viral aggregation