Microbiology

Question 1

What is an infection of the cornea?

Answer 1

Keratitis

Question 2

What is infection of the entire globe?

Answer 2

Endophthalmitis

Question 3

What organisms can cause conjunctivitis in neonates?

Answer 3

Staph aureus
Neisseria gonorrhoeae
Chlamydia trachomatis

Question 4

What are conjunctivitis causes at other ages?

Answer 4

Staph aureus
Strep pneumoniae
Haemophilus influenza (esp. in children)

Question 5

How do you treat bacterial conjunctivitis?

Answer 5

Swab
Topical antibiotics
Drops vs ointments

Question 6

When should you avoid chloramphenicol?

Answer 6

History of aplastic anamia or allergy

Question 7

What are viral causes of conjunctivitis?

Answer 7

Adenovirus
Herpes simplex
herpes zoster

Question 8

What are signs of chlamydial conjunctivitis?

Answer 8

Chronic history
unresponsive to treatment
symptoms of urethritis and vaginitis

Question 9

What is involved in Hutchison & Robinson sign?

Answer 9

Tip of the nose

Question 10

What is a hypopyon?

Answer 10

A greeny yellow dot in the eye

Question 11

What is the treatment for bacterial keratitis?

Answer 11

Admission for hourly drops
Daily review
Assoc. with corneal pathology or contact lens wear

Question 12

What are viral causes of karatitis?

Answer 12

Herpes

Adenovirus

Question 13

Describe herpetic karatitis

Answer 13

Painful
Recurrent
Reduced corneal sensation
steroids can cause corneal melt and perforation

Question 14

Describe adenovirus keratitis

Answer 14

Bilateral
Follows URTI
Contagious
Topical AB to prevent secondary infection
May affect vision
Can give steroids

Question 15

What are fungal causes of karatitis?

Answer 15

Acanthamoeba

Pseudomonas aeruginosa

Question 16

Describe fungal karatits

Answer 16

More idolent than bacterial
History of trauma from vegetation
Long time to heal

Question 17

Describe orbital cellulitis

Answer 17

Painful - esp on eye movement
Assoc. paranasal sinisitus 
Pyrexial
Sight threatening
cared by ENT and optha
CT scan for orbital abscesses

Question 18

Where does orbital cellulitis extend from?

Answer 18

Directly from sinus
From focal orbital infection
Post operative

Question 19

What organisms can cause cellulitis?

Answer 19

Staphylococci
Streptococci
Coliforms
Haemophilus influenzae
anaerobes

Question 20

What is endophthalmitis?

Answer 20

infection inside the eye
very painful with decreased vision
red eye
post surgical or endogenous

Question 21

What is the most common cause of endophthalmitis?

Answer 21

Staph epidermidis

Question 22

What is used to treat endophthalmitis?

Answer 22

Intravitreal amikacin and vancomycin

Topical antibiotics

Question 23

What organisms cause chorioretinitis?

Answer 23

CMV in AIDS
Toxoplasma gondii
Toxocara canis (worm)

Question 24

What is toxoplasmosis?

Answer 24

Protozoan infection 
flu-like
if immunosuppressed, cysts may form
IgG
Can reactivate

Question 25

Describe toxocara

Answer 25

Parasitic nemotode affects cats/dogs cant replicate in humans Form granulomas which can cause irreversible visual loss

Question 26

How do you diagnose an eye infection?

Answer 26

``` Swabs Corneal scrapping aqueous/vitreous for culture microscopy/culture serology ```

Question 27

What 3 things can broad antibiotics do?

Answer 27

Inhibit protein synthesis Inhibit cell wall synthesis Inhibit nucleic acid synthesis

Question 28

Describe chloramphenicol

Answer 28

ointment/drops inhibits peptidyl transferase enzyme Bacteriocidal for strep/heamophilus Bacteriostatic for staph

Question 29

What side effect can chloramphenicol?

Answer 29

Grey baby syndrome

Question 30

What AB inhibit cell wall synthesis?

Answer 30

Penicillins and cephalosporins have common B lactam ring

Question 31

What AB inhibit nucleic acid synthesis?

Answer 31

Quinolones e.g.ofloxacin | inhibit DNA gyrase

Question 32

What antiviral inhibits viral DNA synthesis?

Answer 32

Aciclovir Antivirals used for dendritic ulcers of corneas Dont give steroids

Question 33

How do you treat bacterial conjunctivitis?

Answer 33

Chloramphenicol Fusidic acid Gentamicin

Question 34

What does chloramphenicol treat against?

Answer 34

Bacteria except pseudomonas aeruginosa

Question 35

What does fusidic acid treat against?

Answer 35

staph aureus

Question 36

What does gentamicin treat against?

Answer 36

Gram negative bacteria including coliforms, pseudomonas aeruginosa

Question 37

What is used to treat chlamydial conjunctivitis?

Answer 37

topical oxytetracycline | adults may beed oral azithromycin

Question 38

What is used to treat bacterial keratitis?

Answer 38

A 4-quinolone (Ofloxacin) | Gentamicin and cefuroxime

Question 39

What does A 4-quinolone (Olfoxacin) treat against?

Answer 39

Gram negative bacteria but not strep pneumoniae

Question 40

What does Gentamicin and cefuroxime act against?

Answer 40

gram positive and gram negative organisms when used together