Term
Haemophilus influenzae
reservoir
virulence
clinical
diagnostics
misc |
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Definition
Obligate human paraiste
transmitted via respiratory route
Capsule: 6 types, b is most virulent
Attachment pili
IgA1 protease
ENCAPSULATED - usually type b
Meningitis: 3-36 mo, complications include mental retardation, seizures, deafness, death
Acute epiglottitis
Septic arthritis in infants
Sepsis: esp pts w/o functioning spleen
Pneumonia
NONENCAPSULATED
Otitis media
Sinusitis
COPD exacerbation & pneumonia
Gram stain
Chocolate agar at 80C, lyses RBC, releasing factors X and V
ELISA, latex particle agglutination
Positive Quellung test: due to capsule
Requires 2 factors for growth:
X: Hematin
V: NAD+
"blood loving"
tends to follow the flue |
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Term
Haemophilus ducreyi
reservoir
clinical
diagnostics
misc |
|
Definition
STD
chancroid: painful genital ulcer, often assoc with unilateral swollen lymph nodes that can rupture, releasing pus
Gram stain and culture of ulcer exudate and pus released from LN
Requires factor X (hematin) only |
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Term
Gardnerella vaginalis
reservoir
virulence
clinical
diagnostics
misc |
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Definition
STD
no capsule, no exotoxins
Bacterial vaginitis: foul smelling vaginal discharge (fish), vaginal pruritus, dysuria
Clue cells: vaginal epithelial cells that contain tiny pleomorphic gram-neg bacilli within the cytoplasm
Doesn't require X factor or V factor for growth |
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Term
Bordetella pertussis
reservoir
virulence
toxins
clinical
diagnostics
misc |
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Definition
man: highly contagious
transmitted via respiratory route
Capsule
Beta-lactamase
filiamentous hemagglutinin (FHA): pili rod that extends from surface, enabling bacteria to bind to ciliated epithelial cells of bronchi
Pertussis toxin: activates G pr that i/c cAMP
-i/c sensitivity to histamine
-i/c insulin release
-i/c number of lymphocytes in blood
Extracytoplasmic adenylate cyclase weaknes neutrophils, lymphocytes, monocytes
Filamentous hemagglutinin allows binding to ciliated epithelial cells
Tracheal cytotoxin kills ciliated epithelial cells
Whooping cough
-Catarrhal phase: highly contagious, 1-2 wks, sensitive to antibiotics
-Paroxysmal phase (2-10 wks), whoop, i/c # of lymphocytes in blood smear
-Convalescent stage
Bordet-Gengou media
ELISA
PCR
Direct fluorescein-labeled Ab applied to nasopharyngeal specimens
High risk groups:
infants < 1 yo
Adults as immunity acquired from vaccine wears off |
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Term
Legionella pneumophila
reservoir
virulence
toxins
clinical
diagnostics
misc |
|
Definition
Ubiquitous in man and natural water environments
Facultative intracellular parasite: inhibits macrophage phagosome/endo/lysosome fusions
Superoxide dismutase and catalase-peroxidase protects bact from macrophage superoxide and hydrogen peroxide oxidative burst
Pili and flagella promote attachment and invasion
Secretion of protein toxins like RNAse, phosphlipase A and phosphlipase C
Cytotoxin
Pontiac fever: headache, fever, muscle aches, fatigue, self-limiting
Legionnaires' Disease: pneumonia, fever, non-productive cough
Culture on buffered charcoal yeast extract agar
Serology: IFA, ELISA
Urinary Ag by radioimmunoassay
Facultative intracellular parasite: inside alveolar macrophages
Persons with compromised immune systems are esp susceptible |
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