Virulence Factors Flashcards
Mycobacteria tuberculosis
- Serpentine cord formation (cord factor)
- Mycolic acids prevent attack by lysozyme, complement
- LAM: stimulates host cytokines, TNF, IL-6
Mycoplasma pneumoniae
- Proline-rich adhesion (adhere to cells)
- Protein-M: block antibody
- **Production of oxygen radicals
Corynebacterium diphtheriae
- AB toxin: B binds to receptor; A ADP-ribosylates EF-2 –> stop protein synthesis
- High Fe will repress toxic effects
Bordetella pertussis
- Filamentous hemaglutinin: phagocytosed in macrophages
- Ciliary stasis of mucus escalator
- AB toxin: ADP-ribosylates inhibitory G-protein –> increase in cAMP
- Tracheal cytotoxin
- LPS
Haemophilus influenzae
- LOS
- IgA protease
- **PRP capsule (type b)
Most symptoms from T-cell activation by PG and bacterial replication
Legionella pneumophila
- Type II and Type IV secretion
- Activates macrophage coiling phagocytosis of bacterium
- Prevent phagolysosome fusion
- Release blebs of LPS
EPEC
- Attachment protein
- inhibit water uptake
ETEC
- CFA adhesion pili
EHEC
- Shiga-like toxin: AB toxin protein synthesis inhibitor (becomes systemic)
EIEC
- Invasive colonization factors
EAEC
- Aggregative pili –> infective foci
Salmonella
- Cytotoxic enterotxin
- Typhoid toxin: ADP-ribosylate G-protein; damage DNA
Shigella
- Lyse phagolysosome and replicated in MQ (release IL-1)
- Shiga enterotoxin disrupts protein synthesis
- Spread via actin tails
- Type III secretion
Yersinia pestis
- Type III secretion
- Inhibit MAP kinase (prevent cytokine production and cell replication)
- Prevent phagocytosis
- Prevent platelet aggregation
Vibrio cholerae
- AB toxin: A with ADP-ribosylate G-protein to increase cAMP
Vibrio parahemolyticus
- Biofilms, T3SS, T6SS, hemolytic/cytotoxic enterotoxin
Vibrio vulnificus
- Necrotizing cytotoxin, antiphagocytic capsule
Campylobacter jejuni
- Inflammatory enterotoxin
Campylobacter fetus
- Inhibit complement fixation by C3b
Helicobacter pylori
- Bind base of mucosa
- Bind O bloodgroup antigen
- Urease buffer to raise pH
- VacA: anion channel, vacuolation of epithelial cells, inhibit T cells
- CagA (ulcers)
Treponema pallidum
- Hyaluronidase
- Few surface proteins (hides)
- Tertiary is a hyperimmune response
Neisseria gonorrhea
- Pili, Opa (antigenic variation)
- Por (no phagolysosome fusion), Rmp (prevent Ab binding to other parts), IgA protease
- **LOS
- Fbp (scavenges Fe)
Neisseria meningiditis
- gonorrhea, plus…
- Antiphagocytic capsule
- Pili to cross BBB
Chlamydia trachomatis
- Invasiveness from elementary bodies
- Inhibit phagolysosome fusion
- Induce cytokines
Borrelia recurrentis, hermsii
- Antigenic variation (up and down fever)
Borrelia burgdorferi
- Doesn’t say much! No antigenic variation though
Coxiella burnetti
- Infects lung epithelia
Ehrlichia, Anaplasma
- Infect leukocytes
Rickettsia
- Grow in cytoplasm
- Endothelial pathogen
Bacillus cereus
- Emetic toxin
- Enterotoxins: hemolytic, non-hemolytic, cytotoxin
Bacillus anthracis
- AB toxin (A part has LF for MAP kinase protease and EF for making cAMP)
Brucella
- LPS, PG, cytokines (growth)
- Undulant fever due to release from macrophages
Francisella tularensis
- Grow in MQ and PMNs to high titer
- Resist complement
- LPS, PG
Pasteurella multocida
- **Antiphagocytic capsule
- Pili, adhesion, Fe-binding
- Crazy fast growth
Bartonella hensleae
- T4SS
- Stimulate apoptosis of cells
Leptospria interrogans
- No toxin (just LPS, PG)
- Damage to capillaries
Staphylococcus aureus
- PG, teichoic acids, Protein A (antigens)
- Coagulase
- Hyaluronidase, staphylokinase (tissue invasion)
- Hemolysins: alpha and beta toxins, leukocidin (PVL)
- Exfoliative toxin
- TSST-1: superantigen
- Enterotoxins (food poisoning)
- Quorum sensing (biofilms)
Streptococcus pyogenes
- M protein (heart reactivity)
- Antiphagocytic
- Streptokinase (dissolves fibrin)
- Streptdornase (DNAse)
- Hyaluronidase
- Exotoxins (scarlet fever, TSS)
- Hemolysins
Streptococcus pneumoniae
- Tissue colonization
- IgA protease
Listeria monocytogenes
- Intracellular growth: internalin
- Break out of phagolysosomes
- Actin polymerization
Pseudomonas aeruginosa
- Adhesion pili
- Persister strains
- LPS
- T3SS
- Exotoxins A (EF-2) and S (signal apoptosis)
- Elastase
- Pyocyanin / pyochelin: toxic O2 radicals
Bacteroides fragilis
- Antiphagocytic
- Neuraminidase, heparinase
Prevotella melaninogenica
- Collagenase
Clostridium botulinum
- AB neurotoxin: B binds motor endplates; A block release of ACh by cleaving synaptobrevin (necessary for fusion of synaptic vesicle)
Clostridium tetani
- AB neurtoxin: retrograde transport and prevent GABA release
Clostridium perfringens
- Alpha-toxin: phopholipase for membranes
- Hyaluronidase, collagenase
- Beta-toxin for enteritis necroticans
- Enterotoxin sometimes (like B. cereus)
- Gas from fermentations
Clostridium difficile
- Toxin A: enterotoxin; fluid accumulation
- Toxin B: cytotoxin; kill gut epithelial cells
Aeromonas hydrophila, Plesiomonas shigelloides
- LPS, PG (typical G-)
- ACT toxin (lyse cells, increase cAMP)
- Pili to attach to gut epithelium
