23 - Bacterial Pathogens causing Human Disease Flashcards
on average which is more severe: upper or lower resp infection?
lower
upper resp infection, gram + cocci with large capsule, found in sore throat in kids, humans only known reservoir, resp droplet transmission
streptococcus pyogenes
strep throat is ____, and there is no immunity to reinfection but still need treat with antibiotics
self limiting
strep throat symptoms + skin rash caused by certain strains that produce erythrogenic exotoxin
scarlet fever
erythrogenic exotoxin is carried via ___ throughout body and damages ____
blood; small blood vessels (fever, rash, strawberry tongue)
what cause glomerulonephritis?
immune complexes accumulate in glomeruli of kineys, occurs in recovery stage of untreated strep
autoimmune disease where Ab formed against strep cross react with heart 3-4 wks after self limited strep
rheumatic fever
destructive tissue infection caused by various bacterial species including strep pyogenes (produce enzymes that degrade connective tissue, invade to deeper muscle tissues)
necrotizing fascitis
necrotizing fascitis only spread by:
entry into skin via cuts
why take throat swab?
look for hemolytic colonies on blood agar
infections of lower resp tract caused by variety of bacteria species
pneumonia
types of pneumonia?
lobar (entire section of lungs), bronchial (patches around bronch tubes)
pneumonia leads to:
inflammation of lungs (chills, high fever, bloody sputum) and filling of air spaces with fluids
important virulence factors in pneumonia
bacterial capsules
lower resp infection, slow growing, acid fast, humans only known reservoir, lacks most of usual virulence factors in other bacteria
mycobacterium tuberculosis
all disease in TB due to ____
host immune response
2 forms of TB
primary (first time) and secondary
mech of primary?
airborn/droplet transmission, TB survives and multiplies in phagocytic cells, break open, TH cells activated and stim. macrophage after 3 weeks, which kill M.Tb or create Ghon complex/tubercle to prevent further spread
in ___% of primary cases, tubercles heal by _____
95; fibrosis + calcification
what is secondary TB?
reactivation of dormant tubercles –>activate TH results in delayed hypersensitivity–>can occur years after primary infection
how diagnose TB?
acid fast stain of sputum, lab culture of TB from sputum, tuberculin skin test
gold standard for diagnosis?
lab culture (but slowww)
what is vaccine for TB/
BCG (attenuated, live mycobacterium bovis)
before 1950s , TB treated with ___, now use ____
long term care in sanatorium; anti-mycobacterial drugs (isoniazid, rifampin) for 6-9 mths daily treatment
