Term
| How is the eye normally protected from infection? |
|
Definition
Conjunctiva=mucosal surface on eyelid and cornea
What is present on all mucosal surfaces?
IgA=neutralization and opsinization
Lysozyme=disrupt bacterial cell wall
Normal bacterial flora=Staph epidermis, Corynebacteria xerosis |
|
|
Term
| 3 types of common eye infections |
|
Definition
Blepharitis
Conjunctivitis
Keratitis |
|
|
Term
|
Definition
bacterial cause
S. aureus |
|
|
Term
|
Definition
"pink eye"
inflammation of conjunctiva
Viral OR bacterial |
|
|
Term
|
Definition
inflammation of cornea
vision threatening
Viral (HSV) OR parasitic |
|
|
Term
| Keratoconjunctivitis-basics |
|
Definition
conjunctiva and cornea
Viral (Adenovirus, Chlamydia) |
|
|
Term
| 3 organisms with IgA protease |
|
Definition
SHIN
Strep pneumoniae
H. influenziae
Neisseria |
|
|
Term
| Gram positive organisms that cause eye infections |
|
Definition
Staph aureus
Staph epidermis
Strep pyogenes
Strep pneumoniae |
|
|
Term
| gram negative bacteria causing eye infecitons |
|
Definition
H. influenziae
Neisseria gonorrhoeae |
|
|
Term
| Viruses causing eye infections |
|
Definition
|
|
Term
| Parasites causing eye infections |
|
Definition
Acanthamoeba
Onchocerca volvulus |
|
|
Term
Blepharitis
-causative agent
-symptoms
-lesser causes |
|
Definition
-S. aureus
-itching, burning, redness, CRUSTING OF EYELASHES
-HSV, VZV, Phithiris pubis |
|
|
Term
|
Definition
Hordeolum
-infection of tear gland, sebatious gland, hair follicle
-caused when blepharitis becomes an ACUTE LOCALIZED infection
-S. aureus |
|
|
Term
|
Definition
coag + (destroy H2O2)
cat +
B-hemolytic
mannitol fermentation
highly RESISTANT to penicillin
|
|
|
Term
| Distinguish btw staph and strep |
|
Definition
Staph=CAT POSITIVE
Strep=CAT NEGATIVE |
|
|
Term
| Difference btw Staph aureus and Staph epidermis |
|
Definition
S. aureus=COAG POSITIVE
Staph epidermis (and all other Staph)=COAG NEGATIVE |
|
|
Term
|
Definition
Fibronectin binding protein (adhere to conjunctiva)
Protein A (prevent opsinization)
Coagulase (walls off the bacteria)
Alpha toxin (B-hemolytic)
|
|
|
Term
|
Definition
Bactitracin
Group B Strep=Resistant
Group A Strep=Sensitive |
|
|
Term
Bacterial Conjunctivitis
-causes |
|
Definition
Staph epidermidis
Strep pyogenes
Strep pneumoniae
H. aegyptius
(Staph aureus not so much) |
|
|
Term
| Bacterial conjunctivits vs. Viral conjunctivits |
|
Definition
Bacterial=acute onset
purulent discharge
pruritis MAYBE
Viral=subacute onset (usually occurs after an URI or with an URI
clear, watery discharge
pruritis COMMON
Both=red eye |
|
|
Term
Bacterial conjunctivitis
-diagnosis and treatment |
|
Definition
history and physical
gram stain
topical antibiotic ointment |
|
|
Term
Staph epidermidis
-basics
-virulence |
|
Definition
Coag NEGATIVE
novoviocin sensitive
opportunistic (catheters and prosthetics)
Virulence=BIOFILM (surround organism and prevents against phagocytosis, complement, antibiotics) |
|
|
Term
Streptococcus
-group characteristics. How do you classify them? |
|
Definition
gram + cocci
Chains
facultative anaerobes
non-motile
Classify by:
hemolytic pattern
Lancefield antigens |
|
|
Term
Strep pyogenes
-basics
-habitat
-transmission |
|
Definition
gram + cocci
chains
Group A (B-BRAS)
B-hemolytic
Habitat=nares, URT, skin
Transmission=respiratory secretions
directs contact with infected skin lesions
|
|
|
Term
Strep pyogenes
-virulence |
|
Definition
M protein
Protein F
Protein G
C5a peptidase, IgA protease
Hyaluronidase, DNAses
Streptolysins=O and S (oxygen labile and stabile)
Exotoxins=A-C |
|
|
Term
Strep pneumoniae
-mnemonics
|
|
Definition
MOPS
most common cause of: Meningitis, Otitis media, Pneumonia, Sinusitis
Most OPtochin Sensitive
PPP
Pairs
Polysaccharide capsule
Pneumolysin |
|
|
Term
Strep pneumoniae
-basics
-virulence |
|
Definition
gram +
alpha-hemolytic
PAIRS
NO lancefield antigens
optochin
Virulence=polysaccharide capsule
enzymes (autolysin and pneumolysin) |
|
|
Term
H. aegyptius
-basics
-virulence |
|
Definition
gram - bacilli
facultative anaerobe
requires Chocolate agar with NAD and Factor X
it is H. influenziae, but NON-encapsulated
Virulence
IgA protease
biofilm |
|
|
Term
| 2 bacteria that have BIOFILM |
|
Definition
Staph epidermidis
H. aegyptius |
|
|
Term
Neonatal bacterial conjunctivitis
-causes
-transmission |
|
Definition
Gram - bacteria:
chlamydia trachomatis
Neisseria gonorrhoeae
Transmission=during passage through the birth canal |
|
|
Term
Neisseria gonorrhoeae
-basics
-virulence |
|
Definition
gram -
non-motile
oxidase positive
aerobic
ferments GLUCOSE only
NON-encapsulated
Virulence
Pili (antigenic variation)
LPS (sialic acid)
IgA protease
outer memb proteins |
|
|
Term
|
Definition
1. gonorrhea
2. conjunctivitis
3. opthalmia neonatorum |
|
|
Term
Opthalmia neonatorum
-cause
-basics |
|
Definition
Nesseria gonorrhea
purulent bacterial conjunctivitis
transmitted to neonate during vaginal delivery
occurs 3-5 days after birth
corneal involvement is possible-->blindness!
may be invasive--rhinitis, arthritis, meningitis
|
|
|
Term
|
Definition
resembles gram negative=high lipid content, NO peptidoglycan, penicillin binding proteins, lysozyme resistant
NOT identifiable in gram stain
use immunoflourescence |
|
|
Term
Chlamydia trachomatis
-transmission
-major diseases (serovars)
-pathogenicity |
|
Definition
Transmission=person to person or mother to child
Diseases:
1. Trachoma (A-C)
2. STD (D-K)
-inclusional conjunctivitis and pneumonia (INFANTS)
3. Lymphogranulmoa venerum (L)
Pathogenicity=can form EBs |
|
|
Term
| Chlamydia trachomatis and infants |
|
Definition
Serovars D-K (STD)
Inclusional Conjunctivitis (ICN)
2-14 days
conjunctiva inflammation with purulent yellow discharge
prophylactics
treat systemically to prevent pneumonia
Pneumonia
2-12 weeks
rise in IgM titre |
|
|
Term
Viral conjunctivitis
-causes |
|
Definition
Adenovirus=most common
HSV 1=progress to keratitis
VZV=following primary or secondary disease |
|
|
Term
|
Definition
non-enveloped virus
common following URI
transmitted by respiratory secretions, fomites, and contaminated swimming pools
self limiting, NO antivirals
may progress to kerato-conjunctivitis
|
|
|
Term
Keratitis
-disease
-clinical presentation
-most common agents that progress form conjunctivitis to keratitis |
|
Definition
proliferation of microorganisms in the stroma of the cornea-->causes ulcers, necrosis, accumulation of immune cells, initiate avascular changes in the cornea-->vision threatening
presentation
-pain, photophobia, blurred vision, redness
Progress=S. pneumoniae, H. aegyptius |
|
|
Term
| Most common cause of Keratitis? |
|
Definition
|
|
Term
|
Definition
enveloped
DS DNA
transmitted by direct contact with virus-containing secretions or mucosal/skin lesions containing the virus
Trigeminal ganglion-->reactivation
common cause of BLINDNESS
lesion manifests as a VESICLE |
|
|
Term
|
Definition
Common in U.S.
Protozoan (cyst and trophozoite)
acquired by direct contact
can survive in water sources
|
|
|
Term
| Greatest risk factor for acquiring keratitis? |
|
Definition
|
|
Term
| 2 presentations of Acanthamoeba |
|
Definition
1. Keratitis and ulceration of cornea
-pain, photophobia, foreign body sensation
2. Chronic granulomatous amebic encephalitis |
|
|
Term
Onchocerca volvulus
-basics |
|
Definition
Nematode
cause onchocerciasis=River blindness
transmitted by Black Fly |
|
|
Term
Onchocerca volvulus
-how worm spreads |
|
Definition
| black fly bites you-->larva migrates through tissue-->develops into adult worm-->adult worms group together (2-3)-->encapsulate into BENIGN fibrous nodules-->they are mating and releasing thousands of microfilariae everyday-->River blindness bc the microfilariae get to the cornea |
|
|
Term
| Symptoms of Onchocerca volvulus |
|
Definition
dermatitis/pruritis
skin losses elasticity-->wrinkled
eye lesions-->blindness |
|
|
Term
Keratoconjunctivitis
-cause |
|
Definition
Chlamydia trachomatis (A, B, Ba, C)
Asia, Africa, Mediterranean
-usually infected at age 2, then repeatedly cause infection throughout life
Leading cause of preventable blindness |
|
|
Term
Keratoconjunctivitis
-presentation |
|
Definition
early=inflammatory changes in conjunctiva and cornea
FOLICULAR CONJUNCTIVITIS-fibrosis of eyelid causes it to curl up-->eyelashes abrade the eye's conjunctiva
late=re-infection
-corneal abrasions, scarring, blindness
|
|
|
Term
|
Definition
based on clinical appearance
develop group-specific and serovar-specific antibodies=found in serum and eye secretions
PCR |
|
|
Term
|
Definition
S. aureus
-folliculitis/furunculosis (hairs are infected)
-acute, local infection
-abscess formation associated with hair in ear canal
P. aerunginosa
-swimmer's ear |
|
|
Term
|
Definition
most commonly caused by P. aerunginosa
-develops a moist and elevated pH environment (nice for organism to live) |
|
|
Term
Pseudomonas aeruginosa
-basics |
|
Definition
gram -
aerobic
motile
oxidase +
produces PYOCANIN and SWEET GRAP ODOR
opportunistic=CF patients
Antibiotic resistant |
|
|
Term
|
Definition
extracellular slime
Exotoxin A=ADP-ribosylates EF 2, block protein synthesis, cell death!!
Elastase=inactivates IgA, IgG and several complement components. Targets elastin in lungs and BVs |
|
|
Term
|
Definition
inflammation of middle ear
follows URI
more common in kids bc of eustachian tube
common causes: RSV, influenze, parainfluenza
Strep pneumoniae
H. influenze-Type B |
|
|
