Microbiology Flashcards
What are the causative organisms in neonatal conjunctivitis? What should be done in all diagnoses of neonatal conjunctivitis?
Staph aureus
Neisseira gonorrhoea
Chlamydia thrachomatis
Always refer to opthalmology
What are the common causes of bacterial conjunctivitis in other age groups?
Staph aureus
H. influenziae
Step pneumoniae
How is bacterial conjunctivitis treated?
Chloramphenicol drops qds
When should chloramphenicol be avoided?
Allergy, history of aplastic anaemia
Which viruses can cause conjunctivitis?
Adenovirus, herpes zoster, herpes simplex
In herpes zoster opthalmicus, in which nerve is herpes zoster reactivated?
Opthalmic division of the trigeminal nerve
Which diagnosis should be considered in the young sexually active patient with a chronic bilateral conjunctivitis? What sign might be seen?
Chlamydial conjunctivitis. Conjunctival follicles
What is keratitis?
Inflammation of the cornea
What is hypopyon?
Inflammatory exudate of the anterior chamber of the eye
What is a typical prequel to bacterial keratitis?
Some form of corneal insult, e.g. an abrasion or contact lens use
How is bacterial keratitis treated?
Intensive topical antibiotics- require admission. Cefuroxime and gentamicin cover most
Which viruses can cause keratitis?
Herpes simplex and zoster, adenoviruses
When is fungal keratitis often seen? Which organisms are often causative?
In agricultural settings, or when an insult/injury has occurred with some kind of organic matter. Aspergillus, fusarium
How does fungal keratitis differ in presentation to microbial?
More indolent, gradual progression with less severe symptoms
What is orbital cellulitis often associated with?
Paranasal sinusitis
Which organisms are often responsible for orbital cellulitis?
Staph, strep pygogenes, strep pneumoniae, H. influenziae
How is orbital cellulitis managed?
CT scan, broad spectrum antibiotics, may need to drain f abscess
What is a potential complication of herpetic keratitis?
Dendritic ulcer
What may be the consequence of treating a herpetic keratitis with steroids?
Corneal melt, perforation of the cornea
What is endopthalmitis?
Infection inside the eye
What are the sources of endopthalmitis?
Endogenous bacteria (staph epidermidis), iatrogenic (steroids)
What are the clinical features of endopthalmitis?
Very red, very painful, sight-threating
How is endopthalmitis treated?
Intravitreal vancomycin and amikacin Topical antibiotics (chloramphenicol)
What are the three main causes of chorioretinitis?
CMV in HIV
Toxoplasmosis
Toxocara
Which organism does chloramphenicol not treat?
Pseudomonas aeruginosa
Which organism can fusidic acid be used for?
Staph aureus
