Important Ocular Bacteria

Question 1

What is the most common eye flora

Answer 1

Staphylococcus epidermist

Question 2

What is the most commmon anaerobe

Answer 2

Propionibacterium acnes

Question 3

What are stapylocicci?

Answer 3

GRam positive cocci
Aerobic, facultative anaerobes, produce catalase

Question 4

How do staph aureus and staph epidermis differ

Answer 4

Staph aureus - coagulase positive
Staph epidermis - coagulase negative

Question 5

What are streptococci?

Answer 5

Gram postiive cocci that are catalase negative

Question 6

What is a beta haemolytic strep

Answer 6

Streoptococcus pyogenes

Question 7

What is a alpha haemolytic strep

Answer 7

Streop pneumonia

Question 8

What are examples of gram positive rods

Answer 8

Bacillus
Clostridium
Corynebacterium
Propionibacterium

Question 9

What are bacillia

Answer 9

Large, aerobic, spore formin

Question 10

What is the funciton of spores?

Answer 10

Allow organism to survive long periods - resistant to heat, radiation, dessiccation and chemicals

Question 11

What are clostridia?

Answer 11

Anaerobic spore forming bacteria ( gram postiive)

Produce powerful exotoxins

Question 12

What does clostridium tetani cause? Treatment?

Answer 12

Tetanus toxin is an exotoxin that targets the presynaptic terminals of inhibtory interneurones - tonic spasm of voluntary muscles

Sensitive to penicillin

Question 13

What does Clostridium perfringens cause?

Answer 13

Gas gangrene

Sensitive to penicillin

Question 14

What are corynebacterium

Answer 14

Gram positive aerobic, non-spore forming

Commensal on skin and mucous membranes

Question 15

What are propionibacterium? What can it cause?

Answer 15

Non sporing gram positive
Anaerobic
Normal commensal on eyelids and in Meiboman glands

Can cause chronic blepharitis and endophthalmitis post cataract surgery

Question 16

What is an example of gram positive filament?

Answer 16

Actinomycetes
- grow in the form of mycelial network

Question 17

What is a gram negative cocci?

Answer 17

Neisseria

Question 18

What are gram negative rods?

Answer 18

Pseudomonas
HAemophilus
Moraxella
Enterobacteria

Question 19

What are examples of spirochaetes

Answer 19

Borrelia
Trepnomes

Question 20

What are acid fast bacilli?

Answer 20

Mycobacterium

Question 21

What are mollicutes?

Answer 21

Lack cell wall

Mycoplasma pneumonia
Mycoplasmia hominis
Ureoplasma ureolytica

Question 22

What are neisseriae?

Answer 22

Aerobic gram negative cocci

REquire speical media such as heated blood agar with high CO2 to grow

Question 23

What media is growth of gonnococcus optimal?

Answer 23

Enriched coholate agar - tHayer-Martin medium

Question 24

What is treatment for ophthalmia neonatorum

Answer 24

Cephalosporin
Penicillin

Question 25

What is pseudomonas aeruginosa?

Answer 25

Aerobic, non-motile, gram negative rodW

Question 26

hat is the effect of pseudomonas?

Answer 26

Does not penetrate healthy conreal epithelium but using proteases can pass through traumatised epithelium easily - keratitisW Produces toxin A - breaks down protein glycol matrices

Question 27

What are risk factors pseudomonas

Answer 27

Corneal trauma Thermal burns Vitamin A deficiency Immune suppression

Question 28

What is haemophilus

Answer 28

Non-motile, non-spore, aerobic gram negative rod Cultured on chocolate or blood agar (low CO2)

Question 29

What does Haem. influenza b cause?

Answer 29

URTI - sinusitis - orbital cellulitis Endophthalmitis post intraocular surgery Meningitis Epiglottitis

Question 30

What causes chancroid

Answer 30

H. ducreyi

Question 31

What is moraxella? What do they cause

Answer 31

GRam negative diplobacillus Purulent conjunctival infection

Question 32

What are entrobacteria?

Answer 32

Small aerobic facultative anaerobic bacteria Normal GI flora E. coli - grow MacConkey agar

Question 33

What are spirochaeteso

Answer 33

Helical structure with flagellate structures allowing for spiral motility

Question 34

What are Borrelia?

Answer 34

Large slender organisms

Question 35

How is Borrelia burdogferi transmitted?

Answer 35

Through intermediate host of tick IxodesH

Question 36

ow can Lyme borreliosis be detected

Answer 36

Immunofluorescent assay or ELISA (enzyme linked immunosorbent assay - to measure IgM and IgG antibodies

Question 37

What are treponemes?

Answer 37

Outer envelope Peptidoglycan cell wall

Question 38

What is the cause of syphilis

Answer 38

TReponema pallidum - spirochete - helical bacterium , temp sensitive

Question 39

What does mycobacterium grow on

Answer 39

Lowensetin Jensen medium - cultures can take 8 weeks to grow