Gram Negative Bacteria Flashcards
1
Q
Neisseria gonorrhoeae
A
- facultative, intracellular diplococcus (“gonococcus”)
- surface pili
- motile
- produces IgA protease
- transmission: sexually, congenital
2
Q
gonococcal conjunctivitis
A
- hyperacute mucopurulent conjunctivitis
- may lead to peripheral ulcers (PU)
- can penetrate an intact cornea
- treat with antibiotics (IV PCN, in presence of PU, 4th gen FLQ)
- ophthalmia neonatorum- congenital, after birth
3
Q
moraxella
A
- non-motile coccobacilli
- mucuosal surface commensals
- catalase positive
4
Q
moraxella catarrhalis
A
- diplococcus
- opportunistic pathogen of the respiratory tract
- otitis media, bronchitis, bronchopneumonia
5
Q
moraxella lacunata
A
-angular blepharitis - angle of palpebral fissure; scaly cracked skin appearance
6
Q
bordatella pertussis
A
- primary pathogen
- encapsulated coccobacillus
- transmission (hardy): direct contact, aerosol droplets, fomites
- pertussis: “whooping cough”, prolonged upper respiratory tract infection
- pertussis toxin: necrosis of the ciliated respiratory epithelium
- vaccine available, though protection fades
7
Q
haemophilus influenzae
A
- pleomorphic coccobacillus
- transmission: airborne, direct, opportunistic pathogens
- non-motile
- non-spore forming
- associated with: meningitis, bacteremia, pneumonia, epiglottitis (“thumb sign”)
- vaccine preventable
8
Q
haemophilus influenzae Type a
A
- less virulent form
- unencapsulated
- pneumonia
- otitis media
- conjunctivitis
9
Q
haemophilus influenzae Type b (HiB)
A
- encapsulated*
- more virulent
- highest risk under 6 years
10
Q
orbital cellulitis
A
- post-septal infection
- swollen eyelid, febrile, painful EOMs, reduced VAs, proptosis
- causative organisms: staph aureus, strep pneumoniae, strep pyogenes, H. influenzae (children)*
- treat w/ IV antibiotics
- direct access to the brain so considered an ocular emergency
11
Q
legionella pneumophila
A
- facultative intracellular bacteria
- evades phagolysosomes*
- non-encapsulated coccobacillus
- motile
- non-spore forming
- airborne but not contagious* (not person to person)
- source: water
- Legionnaires Disease- acute pneumonia
- treat with antibiotics
12
Q
pseudomonas aeruginosa
A
- motile rod
- opportunistic
- ubiquitous in soil and water
- biofilm producer*: evades phagocytosis, fruity odor
- transmission: water aerosols, respirators, humidifiers, sink drains, raw vegetables
- hardy pathogen: simple growth requirements, pronounced ability to adhere, resistance to chemical disinfection
- nosocomial infections: pneumonia, wound infections, urinary tract disease (catheters)
- hot tub rash
13
Q
pseudomonas ulcer
A
- found in many eye related products: fluorescein, irrigating solutions, contact lens solutions, cosmetics
- major pathogen in contact lens wearers: does not penetrate intact epithelium, requires a break in epithelium, can cause corneal perforation within 72 hours, primary cause of bacterial keratitis among CL wearers
14
Q
escherichia coli
A
- facultative anaerobic rod
- commensals that live in our gut and produce vitamin K
- 6 majore pathogenic strains
- enteropathic infections (GI infections)
- > 90% of UTI (through cross-contamination of GI and urinary tracts)
- immunocompromised: pneumonia, sepsis
- newborns: meningitis, sepsis
15
Q
enterohemorrhagic E. coli (EHEC)
A
- shiga toxin-producing E. coli (STEC)*
- E. coli O157:H7
- hemolytic uremic syndrome (HUS): causes lysis of RBCs –> can clog glomeruli and cause kidney dysfunction
