Eye and Ear Infections – Flashcards

Conjunctiva=mucosal surface on eyelid and cornea

What is present on all mucosal surfaces?

IgA=neutralization and opsinization

Lysozyme=disrupt bacterial cell wall

Normal bacterial flora=Staph epidermis, Corynebacteria xerosis

Blepharitis

Conjunctivitis 

Keratitis

bacterial cause

S. aureus

"pink eye"

inflammation of conjunctiva

Viral OR bacterial

inflammation of cornea

vision threatening

Viral (HSV) OR parasitic

conjunctiva and cornea

Viral (Adenovirus, Chlamydia)

SHIN

Strep pneumoniae

H. influenziae

Neisseria

Staph aureus

Staph epidermis

Strep pyogenes

Strep pneumoniae

H. influenziae

Neisseria gonorrhoeae

Adenoviridae

HSV 1

VZV

Acanthamoeba

Onchocerca volvulus

-S. aureus

-itching, burning, redness, CRUSTING OF EYELASHES

-HSV, VZV, Phithiris pubis

Hordeolum

-infection of tear gland, sebatious gland, hair follicle

-caused when blepharitis becomes an ACUTE LOCALIZED infection

-S. aureus

coag + (destroy H2O2)

cat +

B-hemolytic

mannitol fermentation

highly RESISTANT to penicillin

Staph=CAT POSITIVE

Strep=CAT NEGATIVE

S. aureus=COAG POSITIVE

Staph epidermis (and all other Staph)=COAG NEGATIVE

Fibronectin binding protein (adhere to conjunctiva)

Protein A (prevent opsinization)

Coagulase (walls off the bacteria)

Alpha toxin (B-hemolytic)

Bactitracin

Group B Strep=Resistant

Group A Strep=Sensitive

Staph epidermidis

Strep pyogenes

Strep pneumoniae

H. aegyptius

(Staph aureus not so much)

Bacterial=acute onset

purulent discharge

pruritis MAYBE

Viral=subacute onset (usually occurs after an URI or with an URI

clear, watery discharge

pruritis COMMON

Both=red eye

history and physical

gram stain

topical antibiotic ointment

Coag NEGATIVE

novoviocin sensitive

opportunistic (catheters and prosthetics)

Virulence=BIOFILM (surround organism and prevents against phagocytosis, complement, antibiotics)

gram + cocci

Chains

facultative anaerobes

non-motile

Classify by:

hemolytic pattern

Lancefield antigens

gram + cocci

chains

Group A (B-BRAS)

B-hemolytic

Habitat=nares, URT, skin

Transmission=respiratory secretions

directs contact with infected skin lesions

M protein

Protein F

Protein G

C5a peptidase, IgA protease

Hyaluronidase, DNAses

Streptolysins=O and S (oxygen labile and stabile)

Exotoxins=A-C

MOPS

most common cause of: Meningitis, Otitis media, Pneumonia, Sinusitis

Most OPtochin Sensitive

PPP

Pairs

Polysaccharide capsule

Pneumolysin

gram +

alpha-hemolytic

PAIRS

NO lancefield antigens

optochin

Virulence=polysaccharide capsule

enzymes (autolysin and pneumolysin)

gram - bacilli

facultative anaerobe

requires Chocolate agar with NAD and Factor X

it is H. influenziae, but NON-encapsulated

Virulence

IgA protease 

biofilm

Staph epidermidis

H. aegyptius

Gram - bacteria:

chlamydia trachomatis

Neisseria gonorrhoeae

Transmission=during passage through the birth canal

gram - 

non-motile

oxidase positive

aerobic

ferments GLUCOSE only

NON-encapsulated

Virulence

Pili (antigenic variation)

LPS (sialic acid)

IgA protease

outer memb proteins

1. gonorrhea

2. conjunctivitis

3. opthalmia neonatorum

Nesseria gonorrhea

purulent bacterial conjunctivitis

transmitted to neonate during vaginal delivery

occurs 3-5 days after birth

corneal involvement is possible-->blindness!

may be invasive--rhinitis, arthritis, meningitis

resembles gram negative=high lipid content, NO peptidoglycan, penicillin binding proteins, lysozyme resistant

NOT identifiable in gram stain

use immunoflourescence

Transmission=person to person or mother to child

Diseases:

1. Trachoma (A-C)

2. STD (D-K)

-inclusional conjunctivitis and pneumonia (INFANTS)

3. Lymphogranulmoa venerum (L)

Pathogenicity=can form EBs

Serovars D-K (STD)

Inclusional Conjunctivitis (ICN)

2-14 days

conjunctiva inflammation with purulent yellow discharge

prophylactics

treat systemically to prevent pneumonia

Pneumonia

2-12 weeks

rise in IgM titre

Adenovirus=most common

HSV 1=progress to keratitis

VZV=following primary or secondary disease

non-enveloped virus

common following URI

transmitted by respiratory secretions, fomites, and contaminated swimming pools

self limiting, NO antivirals

may progress to kerato-conjunctivitis

proliferation of microorganisms in the stroma of the cornea-->causes ulcers, necrosis, accumulation of immune cells, initiate avascular changes in the cornea-->vision threatening

presentation

-pain, photophobia, blurred vision, redness

Progress=S. pneumoniae, H. aegyptius

enveloped

DS DNA

transmitted by direct contact with virus-containing secretions or mucosal/skin lesions containing the virus

Trigeminal ganglion-->reactivation

common cause of BLINDNESS

lesion manifests as a VESICLE

Common in U.S.

Protozoan (cyst and trophozoite)

acquired by direct contact

can survive in water sources

1. Keratitis and ulceration of cornea

-pain, photophobia, foreign body sensation

2. Chronic granulomatous amebic encephalitis 

Nematode

cause onchocerciasis=River blindness

transmitted by Black Fly

dermatitis/pruritis

skin losses elasticity-->wrinkled

eye lesions-->blindness

Chlamydia trachomatis (A, B, Ba, C)

Asia, Africa, Mediterranean

-usually infected at age 2, then repeatedly cause infection throughout life

Leading cause of preventable blindness

early=inflammatory changes in conjunctiva and cornea

FOLICULAR CONJUNCTIVITIS-fibrosis of eyelid causes it to curl up-->eyelashes abrade the eye's conjunctiva

;

late=re-infection

-corneal abrasions, scarring, blindness

;

;

based on clinical appearance;

develop group-specific and serovar-specific antibodies=found in serum and eye secretions

;

PCR

S. aureus

-folliculitis/furunculosis (hairs are infected)

-acute, local infection

-abscess formation associated with hair in ear canal

;

P. aerunginosa

-swimmer's ear

most commonly caused by P. aerunginosa

-develops a moist and elevated pH environment (nice for organism to live)

gram -

aerobic

motile

oxidase +

produces PYOCANIN and SWEET GRAP ODOR

opportunistic=CF patients

Antibiotic resistant

extracellular slime

Exotoxin A=ADP-ribosylates EF 2, block protein synthesis, cell death!!

Elastase=inactivates IgA, IgG and several complement components. Targets elastin in lungs and BVs

inflammation of middle ear

follows URI

more common in kids bc of eustachian tube

common causes: RSV, influenze, parainfluenza

Strep pneumoniae

H. influenze-Type B