Dr. Daniels Flashcards
S. pneumonia phenotype
a-hemolysis on blood
Gram positive cocci
Major cause of worldwide pnimonia
Streptococcus pneumonia
S. penumonia Encounter
Many people are carriers - mainly kids
Present in nasopharyngela mucosa
S. pneumonia Entry
Access to lower airway. Usually cleared by innate immunity, but risk factors can help establish infection (seasons, viral infection, smoking, edema, etc)
S. pneumonia entry/spread
Alveoli fill with fluid, and there is suppurative inflammation in the lungs. This packs the effected tissue with neutrophils, making iit solid instead of spongy (hepatozation)
Diagnosis of S. pneumonia
It can be isolated in culture
Legionella pneumophila phenotype
Gram negative pleomorphic rod
Obligate anaerobe
Fastidious - need special conditions for culture
L. pneumophila encounter
Found in contaminated water
In biofilms with protozoas
Can stand pretty high temperatures
L. pneumophila spread/multiplication
Bacteria in alveoli are phagocytosed by alveolar macrophages, and the virulent strains multiply within autophagosomes.
L. pneumophila damage
Both cell-mediated and virulence factors. L. pneumophila can survive in macrophages, excrete LPS, furthering the inflammation
L. pneumophila treatment
Antimicrobial drugs with good intracellular penetration
Bordella pertussis phenotype
Gram negative rod
Obligate aerobe
Cause of Whooping Cough
Very contageous
B. pertussis encounter, entry, and spread
colonizes in the nasopharynx of adults
Organisms access the trachea/bronchii adhering to cilia via Filamentous hemagglutinin, Pili, and Pertactin
B. pertussis damage
Excretes pertussis toxin and adenylate cyclase/hemolysin. They upregulate host cAMP, decresing neutrophil function and increase capillary permiability; resulting in edema
Pertussis Clinical Stage 1
Catarrhal stage
- really bad runny nose, looking like a bad cold
- Very contagious at this point
- Organisms moving down the respiratory tract
Pertussis Clinical Stage 2
Paroxysmal Stage
- Can last 1-6 weeks (even up to 10)
- Rapid cough followed by “whoop” sound
- Vomiting and exhaustion after coughing fits
Pertussis Clinical Stage 3
Convalescent stage
- Lasts about 2-3 weeks
- Coughing lessens, but fits may return
Pertussis Diagnosis
Hard to diagnose - Suspicion is low during Catarrhal phase, but there are fewer organisms shed in paroxysmal phase
Myobacterium spp. phenotype
Acid fast bacteria
Non-spore forming
Obligate aerobes
Thick, waxy cell wall
Myobacterium Leprae
Granulomatous disease
Found in skin because organisms prefer lower temperatures
Spread through respiratory
Two Types: Tuberculoid Leprosy, and Lepromatous Leprosy
Tuberculoid Leprosy
Milder form of Leprosy
Characterized by sessile lesions - very few bacteria in these lesions
Lepromatous Leprosy
Severe, disfiguring
Many organisms in lesions
Cell mediated immunity is significantly decreased
M. Leprae cultures
Uncultivable in vitro
Can be inoculated in mouse footpad
