Microbiology Flashcards by C C

Which contact lens type poses the highest and lowest risk for microbial keratitis?
- Extended wear, soft, daily disposable, rigid gas permeable

In order from highest to lowest:

Extended wear, soft, daily disposable, rigid gas permeable

How well did you know this?

Not at all

Perfectly

Thioglycollate broth

Anaerobic bacteria

How well did you know this?

Not at all

Perfectly

Giemsa stain

Fungi

How well did you know this?

Not at all

Perfectly

Acanthamoeba

Nutrient free media with E coli

Calcofluor white - fluoresces

How well did you know this?

Not at all

Perfectly

Lowenstein Jensen media

How well did you know this?

Not at all

Perfectly

Methanamine silver (Grocott)

Fungi

How well did you know this?

Not at all

Perfectly

Which 3 bacteria must be grown on chocolate agar?

Neisseria, Haemophilus, Moraxella

How well did you know this?

Not at all

Perfectly

Saboraud’s agar

Fungi

How well did you know this?

Not at all

Perfectly

What is the most common causative organism for bacterial keratitis?

Pseudomonas aeruginosa

Contact lens wearers at risk - grows on biofilms on contact lenses

How well did you know this?

Not at all

Perfectly

What is the treatment for onchocerciasis?

Ivermectin

How well did you know this?

Not at all

Perfectly

Treatment for acanthamoeba?

Topical biguanide e.g. propamidine / chlorhexidine

How well did you know this?

Not at all

Perfectly

What is the major complication of CMV retinitis?

Retinal detachment (50%)

How well did you know this?

Not at all

Perfectly

Treatment for ocular syphillis?

2 weeks IV penicillin G

How well did you know this?

Not at all

Perfectly

What is the tetrad for congenital toxoplasmosis?

4 ‘C’s:

Chorioretinitis
Microcephaly
Intracranial calcifications
Cognitive impairment

How well did you know this?

Not at all

Perfectly

Viral and bacterial conjunctivitis - which is more common for adults and children?

Children- bacterial more common

Adults - viral much more common (80%)

How well did you know this?

Not at all

Perfectly

Bacterial conjunctivitis - most common pathogens for children and adults

Children - HiB, Strep pneumo, Moraxella catarrhalis

Adults - Staph aureus, strep pneumo, HiB

Viral and allergic conjunctivitis - macroscopic appearance?

Viral: follicular (T-cell response)
Allergic: papillary (collections of inflammatory matter)

Which organisms can penetrate an intact corneal epithelium?

CHNLS
Corynebacterium
Haemophilus influenzae
Neisseria
Listeria
Shigella

Which TLR recognises mannan and LPS?

TLR-4

What is the role of IL-8?

Potent neutrophil chemoattractant

What does NOD2 recognise?

Peptidoglycan

Most common cause of post-operative endophthalmitis?

Staphylococcus epidermidis (coagulase-negative staph)

Why is IVT amikacin rather than gentamicin used for endophthalmitis?

Gentamicin causes macular necrosis when injected intravitreally

Treatment of endophthalmitis

IVT vancomycin + amikacin / ceftazidime

Recall: ceftazidime is the only cephalosporin with anti-Pseudomonal activity

What anti-TB drug causes Vitamin B6 deficiency?

Isoniazid

Which glycoprotein is used by HSV to enter cells?

Glycoprotein D Receptors: Nectin, Herpesvirus entry mediator (HVEM) (HSV has 4 glycoproteins used in cell entry)

Which virus causes Kaposi's sarcoma?

HHV-8

What genome type does adenovirus have

dsDNA

Ganciclovir and aciclovir - which one for CMV and HSV?

Aciclovir for HSV | Ganciclovir for CMV (CMV is resistant to aciclovir)

What is the latent host cell type for: - HSV - VSV - EBV

- HSV, VSV: neural ganglia - EBV: B cells (hence post-transplant lymphoproliferative disease is due to proliferation of infected B cells when T cell suppression is removed)

BK and JC viruses are what type of viruses?

Polyomaviruses (dsDNA)

HIV: CD4 counts of below what level place a patient at risk for: 1) TB 2) Toxoplasma 3) CMV retinitis

1) 500 cells/ mm3 2) 200 cells/ mm3 3) 50 cells / mm3 CMV retinitis only occurs in profoundly CD4-depleted AIDS patients

Is subacute sclerosing panencephalitis characterised by mild or florid vitritis?

Mild vitritis - subacute!

What virus is associated with Fuchs heterochromic iridocyclitis?

Rubella | Fuchs --> German --> German measles

Treatment of herpes zoster ophthalmicus

Oral aciclovir - 500mg 5 x/ day | Does not reduce incidence of post-herpetic neuralgia

Staph aureus vs Strep pneumo keratitis: which one is worse?

Strep pneumoniae is worse! | Staph aureus keratitis causes peripheral ulcers and is actually relatively mild compared to pneumococcus and Pseudomonas