Zoonoses-Haemophilus-Listeria Flashcards
What is the gram stain and shape of Yersenia pestis?
Gram−small coccobacilli
Is Yersenia pestis zoonotic?
Yes
What bacteria caused the bubonic plague/black death?
Yersenia pestis
Which 2 organisms typically transmit Yersenia pestis?
Rodnets/rats and fleas
____: (infected lymph node with pus) not contagious
- 50-75% mortality if not treated promptly
bubo
In 10-20% spread to lungs:
•highlycontagious (direct transmission)
•near 100% mortality: black death
Pneumonic plague
The following virulence factors are seen in \_\_\_\_\_\_\_: Pla Yops F1 PsaA Complete resistance Iron Acquisition LPS endotoxin
Yersenia pestis
_____ is a virulence factor of Yersenia pestis:
coded by a plasmid; activates plasminogen activator; destroys C3b, C5a; destroys blood clots; prevents complement-based phagocytosis; clears the way for bacteria to spread from the flea bite site to regional lymph nodes
Pla
_____ is a virulence factor of Yersenia pestis:
coded by a plasmid; interferes with phagocytosis and the immune response by differing mechanisms; loss of virulence if lost; several antiphagocytic proteins and regulators for their expression; injected by type III secretion system
Yops
_____ is a virulence factor of Yersenia pestis:
coded by a plasmid; forms antiphagocytic capsule; capsule formation is induced when temps rise from 26 degrees C to 37
F1
Yersenia pestis carried to bloodstream causes _______
Septicemic plague
Fully virulent Yersenia pestis break out of phagocytes infect the nodes produce buboes causing ______
Bubonic plague
The lungs can become infected by Yersenia pestis, producing the highly contagious and lethal _________
Pneumonic plague
What is the gram stain and shape of Francisella tularensis?
Gram neg coccobacilli
Gram−small coccobacilli
strict aerobic
opportunistic zoonosis(birds, rabbits, tick bites)(bioterrorism)
slow growth in humans(requires cys)
Virulence Factors:
Øintracellular growth in macrophages (prevents phagolysosome fusion) bacteremia
Øthin capsule(anti-complement + weak LPS endotoxin)
Diseases: rabbit fever, tick fever
•ulceroglandular and oculoglandular tularemia
•pulmonary tularemia
Francisella tularensis
Gram -
opportunistic zoonosis by B.melitensis (or bioterrorism)
Organisms penetrate muscous membranes and are carried to the heart, kidneys, and other parts of the body via the blood and lymphatic system; they are resistant to phagocyctic killing and growth within these cells.
Brucella
Systemic bacteremia starting from infected lymph nodes.
“udulant Fever” Brucelloisis
Bang’s Disease
gram -
frequently part of oral flora (carrier rate up to 80%) 6 O-antigen serotypes: a – f: type b is most virulent
Virulence factors:
Capsule B
Haemophilus influenzae
Which O antigen sterotype of Haemophilus influenzae is the most virulent?
Type B
Conjugated vaccine against ______ __ polysaccharides
creates protective IgG,
preventing systemic infections
Vaccine does not protect against
other encapsulated strains and
unencapsulated strains
capsule b
Before the availability of conjugate vaccines in late 1987, H. Infulenzae _____ _ was the most common cause of baterial meningitis in preschool children
type b
Without vaccination to Haemophilus influenzae what results?
systemic diseases
How is Haemophilus influenzae spread?
aerosol transmission and effects the respiratory tracts in the elderly. `
What systemic diseases is one at risk of getting without a vaccine to Haemophilus influenzae?
meningitis
septicemia
cellulitis
epiglottitis
Gram -
facultatively intracellular (prevents endosome-lysosome fusion; autophagosome-like uptake)
Lives and proliferates in the vacuoles of amoebas and in the endoplasmic reticulum of macrophages
Growth up to 46C
Relatively resistant to chlorine and other biocides
Legionella pneumophila
Which disease of Legionella pneumophila was discovered by infected roof AC?
Legionnaires disease:
What are the virulence factors of Legionnaires disease?
Intracellular growth in alveolar macrophages.
nophagolysosomal fusion
What is the transmission method of Legionnaires disease?
aerosol from water sources (living inside amoeba)
No human to human tranmission
Gram +
acid resistant
cold resistant (grows from 1-45C)
Salt resistant
Motile
Food bourne pathogen
facultatiely intracellular (enterocytes, macrophages)
Listeria monocytogenes
_____ is rare but exposure is common (=10% asymptomatic carriers)
Listeriosis
What is a virulence factor for Listeria monocytogenes
Listeriolysin O
pore-forming toxin (phagosome escape)
How does Listeria monocytogenes
cross the membrane into a tissue? (2)
through an M cell
endocytosis from macrophages
In ______ Listeria that lack lysteriolysin, the oxidative burst in infected macrophages, stimulated by CD4+ T cell IFNg, will eradicate the infection.
mutant
In _____ Listeria, where the bacteria escape to the cytoplasm, the additional lytic action by CD8+ CTL s is required before the infection is eradicated.
wild-type
immune compromised
neonates
elderly
pregnant women
contaminated food
Epidemiology of Listeria monocytogenes
