Gram negative bacteria Flashcards
Gram negative cocci – Neisseria gonorhoea – ID
gram negative cocci
-grows on chocoalte agar and low O2 * think candlelight
Gram negative cocci – Neisseria gonorhoea – epi
STI
@ risk: sexually active, neonates
Gram negative cocci – Neisseria gonorhoea – pathogenesis
Endotoxin (LOS)
Gram negative cocci – Neisseria gonorhoea – clinical
cervicitis/urethritis
pharyngitis
proctitis
disseminated dz
Gram negative cocci – Neisseria gonorhoea – tx
ceftriaxone + Azithromycin
Gram negative cocci – Neisseria gonorhoea – prevention
barrier
Gram negative cocci – Neisseria meningitidis – ID
gram negative cocci
-grows on chocolate agar and low O2 (think candelight)
Gram negative cocci – Neisseria meningitidis – epi
college
military
“meningitis belt” Africa
Gram negative cocci – Neisseria meningitidis – pathogenesis
Endotoxin (LOS) –> activates TLR40 –> uncontrolled immune response –> septic shock via vasodilation, hypotension, shock
Gram negative cocci – Neisseria meningitidis – clinical
- meningitis
- meningococcemia (DIC and petechiae –> necrosis and purpura)
Gram negative cocci – Neisseria meningitidis – tx
ceftriaxone
Gram negative cocci – Neisseria meningitidis – prevention
- pre-exposure: vaccine, droplet mask
- post-exposure prophylaxis: ciprofloxacin, rifampin
Gram negative rod – E. coli – ID
gram negative rod
ferments lactose and glucose
Gram negative rod – E. coli – epi
- lives in gut
- most common diseases: UTI, neonatal sepsis, “traveler’s diarrhea” - ETEC, STEC
Gram negative rod – E. coli – pathogenesis
- UTIs: pili bind urinary tract epithelium –> sticky and invasive
- systemic infxn –> cell wall LPS (endotoxin) –> fever, hypotension, DIC
- Enteric infxn –> enterotoxin mediated
Gram negative rod – E. coli – clinical
- UTIs
- systemic: sepsis, neonatal infxn
- gut: watery (ETEC)and bloody diarrhea (STEC)
Gram negative rod – E. coli – tx
- UTIs and systemic: antibiotics
2. gut: usually supportive
Gram negative rod – E. coli – prevention
- UTIs – remove catheters, prophylactic abx
2. gut: hand hygiene
Gram negative rod – Klebsiella – ID
gram negative rod
ferments lactose
Gram negative rod – Klebsiella – epi
- lives in gut – causes infxn when it goes to the wrong place (ie lungs)
- pts usually older, male, EtOH, diabetes, but anyone
Gram negative rod – Klebsiella – pathogenesis
- antiphagocytic capsule
- person aspirates bacteria into GI
Gram negative rod – Klebsiella – clinical
- community acquired pneumonia (with productive cough of “red currant jelly”)
- UTI
Gram negative rod – Klebsiella – tx
antibiotics
Gram negative rod – Klebsiella – prevention
no vaccine
gram negative rod – proteus mirabilis – ID
gram negative rod
NOT a lactose fermenter
-highly motile –> “swarming” overgrowth on blood agar
gram negative rod – proteus mirabilis – epi
stones leading to recurrent UTIs
gram negative rod – proteus mirabilis – pathogenesis
urease positive pathogenesis: proteus makes urease to hydrolyze urea into ammonia –> increase pH –> struvite stones “staghorn calculi” produced –> recurrent UTIs
gram negatie rod – proteus mirabilis – clinical
UTIs
gram negatie rod – proteus mirabilis – tx
antibiotics
gram negatie rod – proteus mirabilis – prevention
no vaccine
gram negative rod – pseudomonas aeruginosa – ID
gram negative rod NOT a lactose fermenter Oxidase positive green-blue pigment fruity odor
gram negative rod – pseudomonas aeruginosa – epi
- lives in water (*think blue and green) especially in ICU
- @ risk: hospitalized pts, especially intubated, burn, cystic fibrosis, neutropenic pts
gram negative rod – pseudomonas aeruginosa – pathogenesis
Endotoxin (LPS) primarily
Exotoxin A for tissue necrosis
gram negative rod – pseudomonas aeruginosa – clinical
sepsis
pneumonia
wound infxn in burn patients
hot tub folliculitis
gram negative rod – pseudomonas aeruginosa – tx
antibiotics
gram negative rod – pseudomonas aeruginosa – prevention
keep WBC > 500, scrupulous care burn pts
gram negative rod – Haemophilus influenzae – ID
small gram negative rod
NOT a lactose fermenter
grown on “chocolate agar”
gram negative rod – Haemophilus influenzae – epi
enters via droplets and lives in respiratory tract
-most @ risk: 6mo-6yo
gram negative rod – Haemophilus influenzae – pathogenesis
IgA protease degrades IgA
Antiphagocytic capsule
Endotoxin LPS
gram negative rod – Haemophilus influenzae – clinical
meningitis otitis media pneumonia sinusitis sepsis **serious MOPSS
gram negative rod – Haemophilus influenzae – tx
antibiotics
gram negative rod – Haemophilus influenzae – prevention
conjugated type b vaccine to reduce meningitis by 90%
gram negative rod – Bortadella pertussis – ID
gram negative rod
NOT a lactose fermenter
gram negative rod – Bortadella pertussis – epi
highly contagious, droplet transmission
@rick: infants and young children
gram negative rod – Bortadella pertussis – pathogenesis
Extoxin: ADP-ribosylation disables Gi protein –> overactivates adenylate cyclase leading to inc cAMP –> respiratory mucosal edema
gram negative rod – Bortadella pertussis – clinical
- inspiratory “whooping” caused by acute tracheobronchitis in kids, 1-4wks
- adults can have 100 day cough w/o whooping
gram negative rod – Bortadella pertussis – tx
antibiotics, supportive care
gram negative rod – Bortadella pertussis – prevention
Acellular vaccine containing inactivated pertussin toxin, often combined with diphtheria and tetanus – DTap
gram negative rod – Legionella – ID
gram negative rod
NOT a lactose fermenter
needs charcoal yeast agar
gram negative rod – Legionella – epi
associated with air conditioners
-typically older, smoker, HIV, transplant IC pt
gram negative rod – Legionella – pathogenesis
can replicate in free-living amoebas in water –> enters respiratory tract –> endotoxin (LPS)
gram negative rod – Legionella – clinical
severe pneumonia + diarrhea
gram negative rod – Legionella – tx
antibiotics
gram negative rod – Legionella – prevention
no vaccine
