EX2 S. pneumoniae, B. pertussis, L. pneumophila, and Mycobacterium - Daniels Flashcards
Strep pneumoniae is what gram stain, shape, oxygen level, spore, and capsule
gram + diplococci aerotolerant anaerobe non-spore forming encapsulated
S. pneumoniae is the main cause of what
community-acquired pneumonia
What are the results of hemolysis, catalase, and what is the test that presumptively identifies strep pneumonia
α-hemolysis (completely lyse)
catalase negative
optochin susceptibility identifies it
What genre of people carry S. pneumoniae and how is it transmitted
young children; nasopharyngeal mucosa
transmission via respiratory secretion/hands
What is the key location of entry for S. pneumoniae
lower airway
What are some risk factors for a S. pneumoniae infection
viral infection smoking loss of consciousness edema in lungs high risk, age, demographics season
What are the four stages of pathogenesis of S. pneumoniae
- alveoli fill with fluid
- early consolidation phase
- late consolidation phase
- recovery phase
What phase of pathogenesis of S. pneumoniae involves neutrophil inflammation
early consolidation phase
What phase of pathogenesis of S. pneumoniae involves the alveoli becoming packed with neutrophils and the affected tissues become solid
late consolidation phase
What is involved with the recover phase of S. pneumoniae infection
macrophages phagocytose debris
normal architecture is re-established
What other diseases besides pneumonia does S. pneumoniae cause
otitis media
pleural effusion (fluid in chest)
bacteremia –> meninigitis
What can you use to treat a S. pneumoniae infection
antibiotics; penicillins, macrolides, pluroquinolones
True or False
There is a vaccine for S. pneumoniae, made of capsular antigens
True
Legionella pneumophila is what gram, shape, oxygen level
gram -
pleomorphic rods
obligate aerobe
What is special about L. pneumophila in regards to lab and identification
it is fastidious; requiring special conditions
requires cysteine
L. pneumophila is a parasite of what
protozoa; biolfims
True or False
L. pneumophila cannot withstand high temps
False; L. pneumophila can withstand up to 46° C
True or Fales
You cannot spread L. pneumophila person to person (by cough)
True
L. pneumophila bacteria are phagocytosed where and by what
they are phagocytosed in the alveoli by alveolar macrophages
L. pneumophila virulent strains multiply where and cause what
multiply within autophagosomes (double membrane RER)
cause inflammation; acute bronchopneumonia
Acute bronchpneumina caused by L. pneumophila can result to what
recruitment of more macrophages
abscess formation
suppurative (neutrophils)
L. pneumophila induces what two immune responses
cell-mediated immune response
virulence/proimflammatory mechanism
This includes the secretion of IFN-γ and causes iron sequestration; decreases replication of bacteria
cell-mediated immune response
L. pneumophila has LPS and flagellin (virulence which allows survival in macrophages) which stimulates what
enhances inflammation via innate immune system
Anti-microbial drugs are good with what
intracellular penetration
True or False
Whopping cough is VERY contagious
True; 90% attack rate
one person can infect 12-15 others
Bordatella bronchiseptica is what
canine infectious tracheobronchitis; kennel cough
Penicillins are not effective against L. pneumophila why
they cannot achieve therapeutic concentration in the macrophages (where it festers)
Bordetella pertussis (and parapertussis) are what gram, shape, and oxygen level
gram -
rods
obligate aerobe
B. pertussis causes what fatal disease in infants
whopping cough
Where is B. pertussis encountered, where does it enter, and where does it spread
encountered via infected people
colonized the nasopharynx
spreads to the trachea and bronchi
What mechanism does B. pertussis use to spread
ciliary adherence via filamentous hemagglutinin, pili, and pertactin
What toxins does B. pertussis contain
pertussis toxin
adenylate cyclase/hemolysin
endotoxin
What does adenylate cyclase/hemolysin do
upregulates host cAMP which decreases neutrophil function, increases capillary permeability; resulting in edema
What toxins does B. parapertussis
adenylate cyclase/hemolysin
endotoxin
(no pertussis toxin)
What is the first stage of B. pertussis infection
catarrhal stage
really bad runny nose; mistaken for a bad cold
EXTREMELY CONTAGIOUS
What is the second stage of B. pertussis infection
paroxysmal stage (cough)
Why is laboratory diagnosis of pertussis tricky
fewer organisms shed in paroxysmal stage
deep nasal swab or nasal flush
diagnosable < 3 weeks of cough onset
What is the main type of prevention against B. pertussis
vaccination
dTAP
Tdap
What is the main component of B. pertussis vaccination
acellular pertussis
Mycobacterium spp. cause what diseases
tuberculosis (M. bovis, M. avium-intracellulare)
leprosy (M. leprae)
True or False
M. tuberculosis is highly contagious
True
Opportunistic disease is caused by what
rapidly growing mycobacteria (RGM)
Mycobacterium live in what oxygen level and do that undergo spore formation or not
obligate aerobes
non-spore forming
Mycobacterium have what type of cell wall
thick sticky cell wall
mycolic acid binds carbol fuscin dye
Mycobacterium are encountered how, they multiple where, and spread where
encountered via ingestion or inhalation
can either multiply in the intestine or lung
Mycobacterium is killed by cell mediated immunity but then under go what
latency period
upon reactivation, is deemed secondary TB
How does a Mycobacterium granuloma form
multiplication in macrophages
activation of CD4 (TH1)
cytokine profile of IFN-γ, IL-12, IL-2
recruitment of more macrophages
What is the structure of a Mycobacterium granuloma
shell of CD4 lymphocytes and a center of infected macrophages
What is used to diagnose TB
intradermal skin test
acid-fast sputum
culture (very slow)
PCR
This is a granulomatous disease what spreads via respiratory route of which the organism prefers lower temperature (skin)
leprosy (M. leprae)
What are the two forms of leprosy
tuberculoid
lepromatous
This is a milder form of leprosy, may be self limiting, and very few bacteria are present in the lesions
tuberculoid leprosy
This is a sever, disfiguring form of leprosy, many organisms are found in the lesions, and cell-mediated immunity is significantly decreased
lepromatous leprosy
True or False
M. leprae is uncultivable in vitro
True
What animal may be a carrier of lepromatous disease (~20%)
armadillos
