[10.36b] Microbiology of Head and Neck Infections (Part 2) V2.1.pdf

Iris, Pupil, Sclera, Eyelid, Lacrimal ducts, Lens, Conjunctiva, Cornea, Retina, Anterior chamber, and Posterior chamber

What are the parts of the eye listed in the anatomical review?

Ciliary body

What structure is the iris connected to?

Choroid plexus

To what structure is the ciliary body connected?

Blepharitis

What is the clinical term for inflammation of the eyelid?

Dacryocystitis

What is the clinical term for inflammation of the lacrimal ducts?

Conjunctivitis

What is the clinical term for inflammation of the conjunctiva?

Keratitis

What is the clinical term for inflammation of the cornea?

Uveitis

What is the clinical term for infection of the iris, ciliary body, and choroid?

Endophthalmitis

What is the clinical term for infection of the anterior and posterior chambers?

Stye or kuliti

What are the two common names for blepharitis in Filipino?

Seborrheic dermatitis or acne rosacea

Blepharitis is usually associated with which two skin conditions?

Staphylococcus spp.

What is the primary infectious etiology of blepharitis?

Nasal carriers

Children with recurrent blepharitis may be what type of carriers of Staphylococcus?

Itchy nose

According to the poor hygiene cycle, what initial action leads to a stye?

External hordeolum

What is an infection of the Gland of Zeis and Moll called?

Internal hordeolum

What is an infection of the Meibomian gland called?

Chalazion

What is a granulomatous inflammation of the Meibomian gland?

Carcinoma

If an ulcerative wound on the eyelid is non-healing, what should be checked for?

Bacteria transfer to another gland

What causes the cycle of recurrent stye infections in the same area?

Warm compress

What is the first-line hygiene treatment to help a stye drain?

Bacitracin / Polymyxin ophthalmic ointment

Name the two topical antibiotics mentioned for blepharitis.

Tetracycline / Azithromycin

Which systemic antibiotics are used when blepharitis is chronic, severe, or causes eye swelling?

Drainage

What is the required treatment for a chalazion where an abscess capsule hinders antibiotic penetration?

Epiphora

What is the medical term for tearing seen in dacryocystitis?

Ocular injection

What is the medical term for redness seen in dacryocystitis?

Rubor, dolor, and tumor

What three signs of inflammation are seen over the duct system in dacryocystitis?

May evoke pus in the tear duct

Why should a clinician avoid pressing the inflamed area in dacryocystitis?

Entropion

What is the term for the inversion of the eyelid?

Ectropion

What is the term for the sagging or eversion of the eyelid?

Cellulitis

Blepharitis and dacryocystitis are etiologically similar to which other skin infection?

Gram positive cocci in clusters

What is the Gram stain and morphology of Staphylococcus?

Catalase positive

Is Staphylococcus catalase positive or negative?

S. aureus

Which Staphylococcus species is coagulase positive?

Novobiocin

Which test is used to differentiate coagulase-negative Staphylococci?

Hyaluronidase

Which Staphylococcus enzyme is known as the spreading factor?

Beta lactamase

Which Staphylococcus enzyme provides resistance to antibiotics?

Cytolysins

Which toxins are associated with increased virulence in MRSA?

Gram positive cocci in chains

What is the Gram stain and morphology of Streptococcus?

Catalase negative

Is Streptococcus catalase positive or negative?

Anaerobic

What is the oxygen requirement classification of Streptococcus based on its catalase status?

Red eye, pink eye, or sore eyes

What are three umbrella terms patients use for conjunctivitis?

Contact lenses or chemicals

Name two noninfectious irritants that cause conjunctivitis.

Dust or pollen

Name two noninfectious allergens that cause conjunctivitis.

Bilateral, painless, watery discharge, and itchiness

What are four characteristics of allergic conjunctivitis?

Unilateral

Viral conjunctivitis usually starts as which presentation before becoming bilateral?

Gritty sensation

How do patients describe the feeling of sand in their eyes during viral conjunctivitis?

Watery to serous

What is the nature of the drainage in viral conjunctivitis?

Uncommon

Is photophobia common or uncommon in viral conjunctivitis?

Preauricular lymphadenopathy

Which specific lymphadenopathy may be present in viral conjunctivitis?

Subepithelial corneal opacities and pseudomembranes

What two findings are seen in severe cases of adenoviral conjunctivitis?

Adenovirus

What is the most common viral cause of conjunctivitis?

Double stranded, unenveloped DNA virus

What is the structure of the Adenovirus?

Rhinovirus and Coxsackievirus

Which two Picornaviruses cause acute conjunctivitis?

Influenza

Which Orthomyxovirus causes acute conjunctivitis?

Epstein Barr Virus (EBV) and Herpes Simplex Virus (HSV)

Which two Herpesviruses cause acute conjunctivitis?

Varicella Zoster virus

Which Herpesvirus presents with systemic symptoms alongside conjunctivitis?

Measles virus

Which Paramyxovirus presents with systemic symptoms?

Bilateral irritation

How does acute bacterial conjunctivitis typically present in terms of symmetry?

Mucopurulent

What is the nature of the secretions in acute bacterial conjunctivitis?

Glued eyes

How does a patient with bacterial conjunctivitis describe their eyes upon awakening?

S. pneumoniae, H. influenzae (non typable), and Moraxella spp.

What are the top three bacterial causes of acute bacterial conjunctivitis?

Staphylococcus aureus

Which bacterium is associated with chronic bacterial eye infections?

Self limited (1 to 2 weeks)

What is the typical clinical course of acute bacterial conjunctivitis?

Shorten duration to 1 to 3 days

What is the benefit of giving topical antibiotics for bacterial conjunctivitis?

Increase antimicrobial resistance (AMR)

What is the primary risk of using topical antibiotics for self-limiting eye infections?

Meningococci

What is the common name for Neisseria meningitidis?

Gonococci

What is the common name for Neisseria gonorrhoeae?

Nonmotile, kidney shaped diplococci

What is the morphology and motility of Neisseria spp.?

Modified Thayer Martin media

On which media does Neisseria form convex, glistening elevated colonies?

Oxidase positive

Is Neisseria oxidase positive or negative?

N. gonorrhoeae

Which Neisseria species is positive for glucose acid production but negative for maltose?

Sunlight, moist heat, and disinfectant

Name three things that rapidly kill Neisseria gonorrhoeae.

Polymorphonuclear cell nuclei

In a gonorrhea Gram stain, what do the large arrows typically point to?

Intracellular gram negative diplococci

In a gonorrhea Gram stain, what do the small arrows point to?

Hyperacute Bacterial Conjunctivitis

Which condition presents with severe pain, copious discharge, and diminished vision?

Meningitis

What is the serious systemic risk of hyperacute bacterial conjunctivitis?

Ophthalmia Neonatorum

What disease is caused by N. gonorrhoeae transmitted to a newborn during birth?

Obligate intracellular parasites

Why can Chlamydia spp. not be grown on standard media?

Cannot synthesize ATP

What metabolic limitation characterizes Chlamydia?

Elementary Bodies (EB)

Which developmental form of Chlamydia is infectious?

Reticulate Bodies (RB)

Which developmental form of Chlamydia is the replicating, non-infectious form?

Giemsa stain

Which stain is used to see Chlamydia since it is not visible on Gram stain?

Inclusion Conjunctivitis

Which condition is caused by Chlamydia trachomatis serotypes D to K?

Oral genital sexual transmission

What is the most common mode of transmission for inclusion conjunctivitis in adults?

Swimming pools

What is a very rare indirect mode of transmission for inclusion conjunctivitis?

Papillae and follicles in the tarsus

What are the clinical manifestations of inclusion conjunctivitis in the eyelids?

Erythromycin suspension

What is the treatment for inclusion conjunctivitis in children?

Azithromycin

What is the treatment for inclusion conjunctivitis in adults?

Trachoma

Which condition is caused by Chlamydia trachomatis serotypes A to C?

Leading cause of preventable blindness

What is the global impact of trachoma?

Pannus formation

What is the term for subepithelial fibrovascular tissue ingrowth into the cornea?

Trichiasis

What is the term for the inward growth of eyelashes seen in trachoma?

Corneal ulceration and scarring

What is the eventual result of trichiasis in trachoma patients?

McCoy cell cultures

Which specific culture method is the gold standard for diagnosing trachoma?

Vitamin A deficiency

Corneal inflammation (keratitis) is usually caused by what nutritional deficiency?

S. pneumoniae, P. aeruginosa, and C. trachomatis

Name the three bacterial causes of microbial keratitis.

Candida spp. and Aspergillus spp.

Name the two fungal causes of microbial keratitis.

Wearing contact lenses

What is the primary risk factor for microbial keratitis?

Acanthamoeba

Which free living protozoa causes keratitis associated with soft gel contact lenses?

Pain not proportional to redness

What is a characteristic symptom of Acanthamoeba keratitis?