bacteria2 Flashcards
organisms most responsible for URT (sinusitis and otitis media)
Strep pneumoniae, Staph aureus, Haemophilius influenzae, Moraxella catarrhalis
most common cause of bacterial meningitis (except in elderly and children)
Strep pneumoniae
primary inflammatory response blocks these…resulting in secondary overgrowth of colonizing bacteria
sinus ostia or eustachian tube
organisms that can cause invasive disease, bacteremia, systemic disease, meningitis from URT (*all have capsule*)
Strep pneumonia, Neisseria meningitidis, H. influenzae B, E. coli
what Neisseria meningitidis patients normally die from
DIC
most common organisms for neonates causing URT/meningitis
E coli, group B strep
most common organisms for adolescents/young adults causing URT/meningitis
N. meningitidis
most common organisms for people across all ages causing URT/meningitis
Strep pneumoniae
key to pathogenesis in organisms that cause URT/meningitis
encapsulation
must have these to fight deep invasion of encapsulated organisms into tissue
antibodies and complement
capsule for Pneumococcus
PspC
capsule for N. meningitidis
LPS
capsule for N. gonorrhea
LOS
capsule for H. influenzae type B
LPS
URT caused by Strep pneumoniae
sinusitis and otitis media
LRT caused by strep pneumoniae
lobar pneumonia
most common cause of community-acquired pneumonia
Strep pneumoniae
virulence factors for Strep pneumoniae
PspC capsule, pneumolysin, pspA (inhibits complement)
these cause secondary asthma due to sinus infection
inflammatory mediators
nutritional requirement for Neisseria
iron
gram stain and metabolism for Neisseria
negative; aerobic or facultative anaerobe
incubation period for Neisseria meningitidis
less than 1 week
where is petechial rash located in N. meningitidis induced DIC/shock (caused by microhemorrhages in capillaries)
extremities and ear lobes
these occur in vessles that causes ischemic necrosis in limbs of N. meningitidis DIC/shock
microthrombi
patients lose adrenal function due to clot/bleeding into adrenal glands in DIC of N. meningitidis
Waterhouse-Friderichsen syndrome
virulence factor for N. gonorrhea…evades mucosal immunity
IgA protease
window of susceptibility for invasive H influenzae (due to being unable to make good protective Ab response to carbohydrate antigens)….solve this problem with VACCINE
3 mo-3 years
3rd most common cause of secondary bacterial infections (sinusitis and otitis media)…gram-neg, present in normal flora
Moraxella catarrhalis
gram stain and metabolism of Bordetella pertussis
negative, aerobic
vaccine to Bordetella is against this….causes local ciliary paralysis w/ secondary inflammation
exotoxin
causes necrotic, coagulative exudate and formation of pseudomembran
Corynebacterium diphtheria
most common cause of death related to Cornyebacterium diphtheria
cardiac failure
does Corynebacterium cause necrosis or inflammation?
necrosis
vaccine for pertussis for children younger than 7
DTaP
vaccine for pertussis which is intended for person 10 years and older
Tdap
Corynebacterium diphtheria inhibits this in cells…leads to necrosis (specifically in myocardium)
protein synthesis
E. coli is considered this kind of organism because it ferments lactose
coliform
what can urease from Proteus mirabilis cause?
chronic pyelonephritis (staghorn calculi)
shape and gram stain of Pseudomonas aeruginosa
rod, negative (aerobic, flagellum!)
exotoxin from Pseudomonas aeruginosa that causes shock
A
lung infection caused by Pseudomonas aeruginosa
fulminant pneumonia
Pseudomonas aeruginosa found in walls of blood vessel causes what characteristic appearance?
blue haze
this commonly causes pneumonia in cystic fibrosis patients
P. aeruginosa
necrosis caused by Legionella pneumophilia (very severe
fibrinopurulent
this organism causes intracellular infection of endothelial cells…with perivascular lymphocytic infiltrate (*perivascular cuffing*)
Rickettsia
gram stain for Rickettsia; intracellular or extracellular?
negative; obligate intracellular
transmission for Rickettsia
arthropod (bite or contamination of abraded skin)
this may appear at inoculation site of Rickettsia transmission
eschar
diagnosis of Rickettsia infection
immunostaining or anti-rickettsial serology
primary location for rickettsia multiplication
small vessel endothelia
primary manifestations of rickettsia infection (*due to vascular leakage secondary to endothelial cell damage*)
rash, fever, CNS, small vessel vasculitis
this Rickettsial group lyses endothelial cells
typhus
this Rickettsial group spreads from cell to cell
spotted fever
Rickettsial infection may progress to this…
hypovolemic shock (w/ peripheral edema)
NK cells produce this in Rickettsia infection; what cells mediate immune response responsible for most of the tissue damage?
IFN-g; cytotoxic T cells
occurs as result of small vessel damage in Rickettsia infection
thrombosis and hemorrhage
these things are seen in severe cases of Rickettsia infection
hypovolemic shock, DIC, pulmonary edema
DDX for rickettsia infection
Meningococcemia, Rubeola, Rubella, Erlichiosis (and Rickettsial disease)
transmission of epidemic typhus (R. prowazekii) from human to human
head lice
responsible for epidemic typhus
R. prowazekii
characterized by centrifugal rash, followed by CNS symptoms (apathy, dullness, stupor, coma) –> high fever, chills, cough, rash, severe muscle pain, sensitivity to light and delirium
epidemic typhus
murine typhus is similar to epidemic typhus but is transmitted via these
fleas on rodents
severe clinical presentation of epidemic typhus (mild is rash and small hemorrhages)
gangrene tips of fingers, nose, penis, scrotum, earlobes, vulva
will find cuff of these around vessels in epidemic typhus infection; what do you see in affected organs?
mononuclear inflammatory cells; ecchymotic hemorrhages
incubation period for RMSF
7 days
general findings for RMSF
fever (high for 2-3 weeks), N/V, headache, muscle pain, hemorrhagic rash (including P/S)
pattern of RMSF rash spreading
periphery to trunk
infiltrate seen in RMSF
perivascular mononuclear
see this in small vessels and arterioles in RMSF
necrosis, fibrin extravasation, thrombosis
is noncardiogenic pulmonary edema transudate or exudate?
exudate
major cause of death in RMSF
noncardiogenic pulmonary edema
will see this in severe infection of RMSF
foci necrotic skin (fingers, ears, scrotum, toes, elbows)
gram negative diplococcus, normal flora in URT, *third most common cause of secondary bacterial infections*
Moraxella cararrhalis
C diphtheria has this toxin that can cause damage to distant organs
exotoxin A
pleomorphic gram negative, aerobic, coccobacillus that has exotoxin that causes local ciliary paralysis
B pertussis
pertussis exotoxin causes this
ciliary paralysis
C diphtheria exotoxin causes this due to protein synthesis inhibition
fatty myocardial change, myofiber necrosis, polyneuritis
what is most common cause of death due to diphtheria?
cardiac failure (due to exotoxin)
gram negative, rod bacteria cause these 3 kinds of infections
UTI, intra-abdominal infection, nosocomial pneumonia
cause of most uncomplicated UTI in absence of obstruction
E coli
this bacteria will cause suppurative infection of abdominal cavity secondary to obstruction (cholecystitis, appendicitis, diverticulitis) or perforation/trauma
E coli
pneumonia caused by E coli in debilitated patients (dangerous for aspiration)
gram neg hemorrhagic bronchopneumonia
