infectious disease Flashcards
what are 4 major gram + cocci bacteria? how are they shaped?
staphylococcus aureus - grapes/clusters
staphylococcus epidermitis: grapes/clusters
streptococcus viridans (GABHS) - chains/pairs
Streptococcus pneumococcus - chains/pairs
Staph aureus is found where? how is it spread?
normal flora of skin/nose, spread thought lesions, fomites
in diagnosis, how is staph differentiated from strep?
staph has catalase (is catalase positive) - aka when its added to hydrogen peroxide, O2 is produced.
treatment options for staph? MRSA?
methacillin, nafcillin, dicloxacillin (PCNs)
if MRSA- vancomycin
what diseases can staph aureus cause? (7)
skin infections, bacteremia/sepsis, acute endocarditis, PNA, osteomyelitis/septic arthritis, food poisoning, TSS
what does Staph epidermitis infect?
assoc. with IV catheters and damaged/ prosthetic heart valves –> insidious onset and less virulent
what diseases does strep (GABHS) cause? (5)
skin infection, pharyngitis + scarlet fever + rheumatic fever, mitral valve disease, acute glomerulonephritis, TSS
where is strep viridans found and how does it spread?
throat/skin spread through resp. droplets
how is strep diagnosed?
catalase negative
beta hemolysis and bacitracin sensitivity = GABHS
treatment for strep?
PCN to prevent rheumatic fever
what disease does strep pneumo cause? (3)
lobar PNA, adult meningitis, URI (kids)
- found in nasopharynx
what are the 2 gram - cocci? what shaped are the?
Neisseria meningitis and Neisseria gonnorhoeae
both: kidney bean shaped
how do you differentiate the two gram - cocci?
N. meningitis ferments maltose
N. gonorrhoae does NOT ferment maltose
what 3 dz does N. meningitidis cause?
meningococcemia (w/ petechial rash)
meningitis (w/ increased PMNs in CSF)
waterhouse friedrichsen (fever, purpura, DIC, bilateral adrenal hemorrhage, shock, death)
what dz does N. gonorrhea cause?
males- urethritis, epididymitis, prostatitis
female- cervicitis, infertility, PID, ectopic, ophthalmia neonatorum
both- septic arthritis
treatment for gram - cocci (Neisseria meningitidis and gonorrhoaea)? prophylaxis?
ceftriaxone (general 3 cephalosporin)
prophylaxis: N. meningitidis - rifampin, N. gonnorhoaea - erythromycin eye drops for newborns
what is the likely bacterial meningitis in 0-6months? 6mo - 3 yrs? 3-15yrs? >15 yrs?
0-6mo : group B strep, E coli, Listeria
6mo - 3yr: H flu B
3yr- 15 yrs: N. meningitidis
>15yrs: Strep pneumo
what are the gram + rods? (3)
Clostridium ( C. tetani, C. botulinum, C. perfungens, C. difficile)
Corynebacterium diptheriae
listeria monocytogenes
what bacteria group are all anaerobic, spore-forming, and with exotoxins ?
gram + rods Clostridiums
what is the MOA of C. tetani? C. botulinum?
tetani: blocks release of inhibitory glycine neurotransmitter
botulinum: blocks Ach release
what is the MOA of C. difficile?
suppression of normal flora allows overgrowth, meds that cause this - clindamycin, ampicillin, cephalosporins
treatment for gram + rods?
C. tetani - tetanus immunoglobin +/- (prevention tetanus toxoid)
C. botulinum - antitoxin
C. perfingens - debridement, O2 gas, PCN
C. Diff - metronidazole, vancomycin
Diptheriae- antitox, PCN
listeria- ampicillin
what antibiotic can you NOT use for C. botulinum? why?
PCN will burst cells and release the toxin
what does the gram + rod diptheria cause? (3)
gray fibrinous exudate in throat (pseudomembrane) - airway obstruction, myocartidis, recurrent laryngeal nerve palsy