Virulence/Immunology Flashcards
Common cold
Rhinovirus
1. Host receptor
2. How it promotes virulence
- ICAM-1 (CD54)
2. Binds human cells and infects
Bacterial rhinosinusitis
S. pneumoniae
1. Virulence factor
2. How it promotes virulence
- Capsule
2. Prevents WBC phagocytosis
Bacterial rhinosinusitis
H. influenzae
1. Virulence factor
2. How it promotes virulence
- Capsule
If non typeable: lipooligosaccharide (LOS) - LOS helps bind to nonciliated epithelial cells
Rhinocerebral mucormycosis
Rhizopus and Rhizomucor
1. Virulence factor
2. How it promotes virulence
- Fungal spores
- Spores germinate and hyphae penetrate host tissue and clog vessels. Necrosis results. IC host can’t phagocytize spores fast enough
Pharyngitis
S. pyogenes
1. Virulence factor
2. How it promotes virulence
- Hyaluronic acid capsule and M protein
2. Both prevent WBC phagocytosis
Scarlet fever
S. pyogenes
1. Virulence factor
2. How it promotes virulence
- Streptococcal Pyogenic exotoxin A-C (Spe A-C, erythrogenic toxin A-C)
- Spe A-C can cause damage to capillary walls in skin - causing rash. Also are super antigens that cause overstimulation of immune cells and streptococcal toxic shock syndrome
Rheumatic heart disease following pharyngitis
S. pyogenes
1. Virulence factor
2. How it promotes virulence
- M protein
- Antigenic and causes host cells to make antibodies that react with M proteins but also with host proteins on the surface of the heart valves
Diphtheria
Corynebacterium diphtheriae
1. Virulence factor
2. How it promotes virulence
- Diphtheria toxin
2. ADP ribosylation if host cell elongation factor II stopping protein production and causing cell death
Epiglottitis
H. influenzae type B
1. Virulence factor
2. How it promotes virulence
- Capsule
2. Prevents WBC phagocytosis
Bronchiolitis
RSV
1. Host receptor
2. How it promotes virulence
- CXCR1 on ciliated human airway epithelial cells OR heparin sulfate on immortalized tissue culture cells
- Allows virus to bind and then infect
Influenza
Influenza virus A
1. Virulence factor
2. How it promotes virulence
- Hemagglutinin and neuroaminidase
2. Hemagglutinin helps binding. Neuraminidase helps virus escape host cells
Whooping cough
Bordetella pertussis
1. Virulence factor
2. How it promotes virulence
- Filamentous hemagglutinin, cytotoxin, pertussis toxin
- FH: attachment to ciliated epithelial cells
Cytotoxin: cell death of cells that line trachea
Pertussis toxin: causes nearly ALL of the cell damage of the trachea by ADP ribosylating guanine-nucleotide-binding protein (G protein)
Pneumonia S. pneumoniae H. influenzae K. pneumoniae 1. Virulence factor 2. How it promotes virulence
- Al have capsules
2. Prevent WBC phagocytosis
Pneumonia
Mycoplasma pneumoniae
1. Virulence factor
2. How it promotes virulence
- Cytadherence organelle
2. Adherence to ciliated columnar epithelial airway cells
Pneumonia
Viruses and Chlamydia bacteria species
1. Virulence factor
2. How it promotes virulence
- Invade and live in alveolar macrophages and other cells of the lungs
- Avoid elimination, harder to detect