Microbiology Flashcards
What is the common bacterial causes of conjunctivitis in adults?
Staph aureus
Strep pneuomiae
What is the common bacterial causes of conjunctivitis in children?
H flu
What is different about bacterial conjunctivitis in neonates?
Must be referred to ophthalmology due to possibility of contraction during birth
Which two bacteria is particularly worrying in a neonatal conjunctivitis?
N gonorrhoeae
Chlamydia trachomatis
What are common symptoms of bacterial conjunctivitis?
Hazy vision Sticky discharge- often at night Pussy exudates Redness Gritty feeling
What kind of swabs are taken for conjunctivitis?
Bacterial
Viral
Chlamydia
What topical antibiotic is usually given?
Chloramphenical
What are the pros/cons of drops vs ointments?
Drops need to be kept in fridge
Drops difficult to keep sterile
Ointment harder to apply but gives soothing effect
When must chloramphenical be avoided?
If history of aplastic anaemia
What are the signs of aplastic anaemia, clinically?
Anaemia
Low WBC
Low platelets
If the eye gets worse on abx treatment in bacterial conjunctivitis what must be considered?
An allergy to chloramphenical
What are the symptoms of adenoviral conjunctivitis?
Gritty feeling
Red eyes
watery discharge
Starts with URTI
What is the treatment for adenoviral conjunctivitis?
Self resolving
But symptomatic treatment of antihistamine plus artificial tears
What is important to remember with pink eye (adenovirus conjunctivitis) ?
It is contagious.
Spread by share of eyeliners
Which other two viruses commonly cause conjunctivitis?
Herpes zoster
Herpes simplex
In a patient with conjunctivitis and also urethritis/vaginitis, what must be considered?
Chlamydial infection
How is chlamydial conjunctivitis treated?
Topical and oral azithromycin
Further STI screening
What ethical dilemma might occur when testing for chlamydia?
Need to tell patient what you’re testing for and ask for contact number
Contact tracing if positive
What sign is present in chlamydial conjunctivitis?
Wet rice grains in internal eyelid
What is keratitis?
Inflammation of cornea
What is a hypopyon?
Level of white blood cells seen in the iris
What bacteria are to blame for keratitis?
Staph aureus
Strep pneumoniae
H flu
Staph epidermidis
What is often seen in bacterial keratitis?
Ulcer
What is the first step in treatment of bacterial keratitis?
Corneal scrape
What does the treatment for bacterial keratitis consist of?
Admission.
Hourly drops
What condition presents with a dendritic ulcer?
Herpetic keratitis
What should never be given for herpetic keratitis?
Steroids.
Steroids can cause corneal melt
What does recurrent herpetic keratitis result in?
Reduced corneal sensation
What kind of viral keratitis can steroids be given for?
Adenoviral keratitis
What sign may be seen in adenoviral keratitis?
Subepithelial infiltrates
Who tends to get fungal keratitis?
Farmers or gardeners
What is involved in fungal keratitis treatment?
Long treatment (6 months) Topical chlorhexadine
What is associated with contact lenses and keratitis?
Acanthamoeba
P aeruginosa
What is associated with orbital cellulitis?
Pain
Proptosis
Pyrexia
Paranasal sinusitis
Why is orbital cellulitis an urgent case?
Sight threatening
Requires hospitalisation.
What tests need to be done for orbital cellulitis?
Microbiology swabs
CT scan to differentiate between preseptal and orbital
What can cause orbital cellulitis?
Sinus infection
Superficial infection e.g. folliculitis or chalazion
What is a chalazion?
Cyst in eyelid caused by a blocked gland
What causes endophthalmitis?
Surgical complication or endogenous e.g. endocarditis
What are the symptoms of endophthalmitis?
Acute
Decreased vision
Very red
What is the most common cause of endophthalmitis?
Staph epidermidis
What is the treatment of endopthalmitis?
Intravitreal vancomycin
Topical antibiotics
What is chorioretinitis?
Inflammation of the choroid
What causes chorioretinitis in patients with AIDs?
CMV
What other organism can cause chorioretinitis?
Toxocara canis (worm)
Where do toxocara normally live?
Cats and dogs
Cannot replicate in humans
What test is done for toxocara?
Serology
Why is chloramphenicol not used on babies?
Grey baby syndrome
Hypotension
Low tone
Cardiovascular collapse
What is dacrocystitis?
Infection of nasolacrimal sac, due to obstruction of the lacrimal gland
What antibiotic should be given if staph aureus is organism?
Fusidic acid
