vaccine preventable bacterial diseases Flashcards
toxoid
toxin preparation rendered non-toxic (e.g. Rx with formalin) but retains the ability to stimulate the formation of antitoxin. Ex: diphtheria toxoid
what kind of immunity protects quickest? whats wrong with it?
passive immunity but it doesnt persist (ex from mother)
5 categories of bacterial vaccines
live
attenuated
toxoid (ex: tetanus or diphtheria (dTap)) polysaccharide alone
conjugate (polysaccharide + protein) combined
T independent antigens like polysaccharides are not recognized by… unless…
kids less than 2 (so they would not react with B cell production or antibody production)
when polysaccharide is conjugated to protein, all ages can recognize it and respond with T cell help –> memory B cells and antibody made!!
bordatella pertussis
Causes pertussis (whooping cough)
gram negative rod
encapsulated when virulent
virulence factors = pertussis toin (LPF), adenylate cyclase, and adhesins
growth requires enriched media that binds fatty acids like BG (bordet gengou) agar or RL (regan lowe) charcoal with horse blood
pertussis
caused by bordatella pertussis
Acute infection of tracheobronchial tree
three stages: 7-10 day incubation –> catarrhal, paroxysmal, and convalescent phases
infants <1 at risk; adults with waning immune respnse may present with long-standing cough with no “whoop”
virulence factors of B. pertussis
1) pertussis toxin (lymphocytosis promoting facotor) 2) extracellular adenylate cyclase (resembles anthrax, increases cAMP and increased fluid secretion in URT)
3) filamentous hemagglutinin and pertactin (adhesive factors)
4) tracheal cytotoxin (destroys ciliated epithelial cells)
mechanism for pertussis toxin
aka lymphocytosis promoting factor (LPF) activates membrane adenylate cyclase of eukaryotic cell via ADP-ribosylation of the regulatory protein Gi
increases cAMP –> increases fluid secretion in URT
pathogenesis of pertussis
Colonization (without invasion) of ciliated bronchial epithelia via filamentous hemagglutinin and pertactin localized damage by tracheal cytotoxin impaired host immune response by adenylate cyclase systemic effects like lymphoxytosis - by pertussis toxin
three stages of pertussis
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lab diagnosis of pertussis
nasopharyngeal aspirate and plate onto regan-lowe charcoal medium
isolation and identification in 3-7 days –> shows “mercury drop” colonies
vaccine for pertussis?
DTaP
-purified inactivated B pertussis products
treatment for pertussis
erythromycin
*paroxysmal stage may be too late to treat effectively
corynebacterium diphtheriae
causes diphtheria
gram + rods that form chinese letters
nonmotile, nonspore forming, catalase +
diphtheria toxin –> ADPribosylates EF-2 and shuts down protein synthesis (cytotoxic)
diphtheria
a toxin mediated disease caused by corynebacterium diphtheriae
affects mucuous membranes of nose and throat –> pseudomembrane in throat
