Microbiology

Question 1

types of gram positive bacteria:

Answer 1

cocci and bacilli

Question 2

types of gram negative bacteria

Answer 2

cocci, cocci-bacilli and bacilli

Question 3

examples of cocci gram positive bacteria

Answer 3

step and staph

Question 4

examples of cocci gram negative bacteria

Answer 4

neisseria

Question 5

examples of cocci-bacilli gram negative bacteria

Answer 5

H. influenzae

Question 6

gram negative bacilli bacteria

Answer 6

pseudomonas

Question 7

types of eye infections and what they affect:

Answer 7

conjunctivitis - conjunctiva
keratitis - cornea
endophthalmitis - entire globe
cellulitis

Question 8

causes of bacterial conjunctivitis in neonates

Answer 8

staph aureus, Neisseria gonorrhoea, chlamydia trachomatis

Question 9

causes of bacterial conjunctivitis in all other ages

Answer 9

staph aureus, strep pneumonia and H. influenza

Question 10

what causes bacterial conjunctivitis especially in children?

Answer 10

H. influenza

Question 11

what is the treatment of bacterial conjunctivitis?

Answer 11

swab, topical antibiotic - chloramphenicol qds
avoid is aplastic anaemia/allergy
allergy is noted if there is worsening symptoms

Question 12

what are the causes of viral conjunctivitis?

Answer 12

adenovirus, herpes simplex, herpes zoster

Question 13

what is the appearance of adenovirus conjunctivitis?

Answer 13

pink eye, tearing, photophobia, lid swelling, decreased vision

Question 14

what is the appearance of herpes simplex?

Answer 14

corneal ulcers,

Question 15

what to suspect in bilateral conjunctivitis in young adults?

Answer 15

chlamydial conjunctivitis

which is unresponsive to treatments

Question 16

how does chlamydial conjunctivitis present?

Answer 16

with or without vaginitis and it requires contact tracing
follicles
sub tarsal scarring

Question 17

what causes microbial keratitis?

Answer 17

bacteria, viruses, fungi

Question 18

what is a hypo-yon?

Answer 18

leukocytic exudate

Question 19

what is associated with other corneal pathology or contact lens wear?

Answer 19

bacterial keratitis

need admission for hourly drops and daily review

Question 20

what causes viral microbial keratitis?

Answer 20

herpes, adenovirus

Question 21

how does herpetic keratitis present?

Answer 21

dendritic ulcers
very painful
can be recurrent

Question 22

what happens when you treat herpetic keratitis with steroids?

Answer 22

corneal melt and perforation of the cornea

Question 23

how does adenovirus keratitis present with?

Answer 23

sub epithelial infiltrates
bilateral
follows URTI
contagious may affect vision
can give topical AB to prevent secondary infection
can require steroids to speed up recovery if it becomes chronic

Question 24

what causes keratitis in contact lens wearers?

Answer 24

acanthomoeba and pseudomonas aeruginosa

Question 25

presention of fungal keratitis?

Answer 25

more indolent course than microbial keratitis, history of trauma from vegetation and takes a long time to heal

Question 26

what is the presentation of orbital cellulitis?

Answer 26

``` painful - on eye movements proptosis often associated with paranasal sinusitis pyrexial sight threatening cared for by ENT and Ophthalmology CT scan to identify orbital abscesses ```

Question 27

orbital cellulitits

Answer 27

direct extension from sinus extension from focal orbital infection (infected chalazion, dacryocysitis) post-operative and need to differentiate between preseptal and orbital

Question 28

what are the organisms that cause orbital cellulitis?

Answer 28

staphylococci, streptococci, coliform, H. influenza, anaerobes

Question 29

treatment for orbital cellulitis

Answer 29

any suggestion of restriction of muscles or optic nerve dysfunction requires scan, broad spectrum AB and monitor closely and sometimes an abscess will require drainage

Question 30

what is endophthalmitis?

Answer 30

devastating infection inside of the eye, post-surgical or endogenous. Painful +++ with decreasing vision, very red eye and sight threatening

Question 31

what causes endophthalmitis>

Answer 31

often conjunctival "commensals" | most common - staph epidermidis

Question 32

treatment of endophthalmitis?

Answer 32

intravitreal amikacin/ceftazidime/vancomycin and topical antibiotics

Question 33

what is the role of systemic antibiotics in endophthalmitis treatment?

Answer 33

EVS is the main body of evidence but at that time 4th get fluroquinolones which have better penetration of blood ocular barrier were not available

Question 34

what causes chorioretinitis?

Answer 34

CMV in AIDs, toxoplasma gondii, toxocara canis

Question 35

what is seen in optic disc of patients with CMV in AIDs?

Answer 35

hemorrhages

Question 36

what causes toxoplasmosis?

Answer 36

protozoan infection, toxoplasmosis gondii from cats and raw meat

Question 37

presentation of toxoplasmosis?

Answer 37

mild flu like illness which rarely causes any further problems. IN immunocompetent patients it enters latent phase with cysts forming

Question 38

what is seen in toxoplasmosis?

Answer 38

very common - specific IgG antibodies can reactivate requires systemic treatment if sight threatening

Question 39

what is toxocara?

Answer 39

``` parasitic nematode affects cats or dogs unable to replicate in humans hence remains an immature form of the worm self-limits as they cannot replicate ```

Question 40

what is formed in toxocara?

Answer 40

form granulomas which van cause irreversible visual loss

Question 41

how to diagnose chlamydial/viral eye infections?

Answer 41

swabs for culture

Question 42

how to diagnose bacterial keratitis?

Answer 42

corneal scrapes

Question 43

how to diagnose endophthalmitis?

Answer 43

aqueous/vitreous for culture

Question 44

how do you diagnose acanthamoeoba?

Answer 44

microscopy/culture

Question 45

how do you diagnose toxoplasma and toxocara?

Answer 45

serology

Question 46

what are the 3 broad categories of antibiotics?

Answer 46

inhibit protein synthesis, cell wall synthesis and nucleic acid synthesis