Exam 3 (Zoonoses, Hawmophilus, Listeria) Flashcards
Is Yersenia pestis G+ or G-?
G-
What organism is known for the plague/black death?
Yersenia pestis
Once a human is infected with Yersenia pestis, it can cause what two forms of the disease?
- Bubonic: swollen lymph nodes can burst and lead to…
- Septicemic: within the blood stream
What form of the plague is most contagious?
Pneumonic plague
The plague spread from human to human is then called….
demic plague
Francisella tularenis
Gram:
Epidemiology:
Gram: G-
Epidemiology: opportunistic zoonosis
Virulence Factor of Francisella tularenis?
- intracellular growth in macrophages
- prevents phagolysosome fusion -> bacteremia
What is rabbit or tick fever?
- ulceroglandular and oculoglandular tularemia
- pulmonary tularemia
Brucella
Gram:
Epidemiology: (what specific organism?)
Gram: G-
Epidemiology: opportunistic zoonosis by B. melitensis
How does “Undulant Fever” from B. melitensis start?
-organism penetrates mucus membranes and carries to heart and other organs via lymphatic system and resist phagocytic killing
Is Haemophilus influenzae G+ or G-?
G-
H. influenzae is frequently part of ________ flora and has __ O-antigen serotypes with type __ most virulent
- oral
- 6 (a-f)
- b
What is the main virulence factor of H. influenzae?
capsule b (the most virulent O-antigen serotype)
Conjugated vaccine against capsule b polysaccharides of H. influenzae stimulates production of what antibodies?
IgG
What was the most common cause of bacterial meningitis in preschool children before 1987?
H. influenzae type b
In unvaccinated children, encapsulated strains of _______________ can cause systemic diseases like __________, _________, __________, and ________.
- H. influenzae
- meningitis
- septicemia
- cellulitis
- epiglottitis
Epidemiology of Haemophilus influenzae?
- aerosol transmission
- respiratory tract in elderly
Legionella pneumophila
Gram:
Growth temp:
Resistant to:
Gram: G-
Growth temp: up to 46 C
Resistant to: chlorine and other biocides
What is the main virulence factor of Legionnaire’s disease?
Legionella pneumophila
-inhibition of phagosomal fusion allows for growth within the ER of alveolar macrophages
Transmission method of Legionella pneumophila?
-aerosol from water sources (from amoeba)
Symptoms of legionnaires’ disease?
- severe pneumonia
- necrotic abscesses
- *especially in immune compromised and elderly pts**
Is Listeria monocytogenes G+ or G-?
G+
L. monocytogenes is resistant to what three things?
- acid
- cold
- salt
What is the mechanism of action of listeriolysin O in L. monocytogenes?
- acid activated hemolysin for beta-hemolysis
- is a pore forming toxin that allows for phagosome escape
What pathogen is associated with food borne illnesses even when kept in cold temps?
Listeria monocytogenes
How do L. monocytogenes bacteria enter host cells?
Enter through M cells of digestive tract, are engulfed by macrophages, inhibit phagosome fusion, exit macrophage, enter host cells via endocytosis, move from cell to cell by actin filaments
Mutant listeria lacking lysteriolysin can be killed with what kind of immune response?
CD4+ T cells binding to MHC Class 2 receptors on macrophages
-bacteria are in a phagosome
Wild type listeria with lysteriolysin can be with what kind of immune response?
CD8+ T cells binding to MHC Class 1 receptors on the infected cell
-bacteria are not in a phagosome
Listeria monocytogenes infections are most commonly seen in….
- immunocompromised pts
- neonates
- elderly
- pregnant women
- from contaminated food
