Unit 3- Moraxella

Question 1

Moraxella bovis

Answer 1

Gram neg diplococci, rod shaped around penicillin, aerobe, nonsaccharolytic, most other Moraxella are commensal

Question 2

Infectious Bovine Keratoconjunctivitis

Answer 2

Moraxella bovis, normally upper respiratory infection, attaches and sticks to cornea, conjunctivitis, keratitis, corneal ulceration

Question 3

Moraxella Predisposing Factors

Answer 3

Sunlight, non hooded eyelid breeds (Herefords), flies involved in transmission, irritation from dust or grass, prior infection, older animals

Question 4

Pinkeye

Answer 4

Moraxella, corneal vascularization, pannus formation, miotic pupil, ulceration, glaucoma, secondary infection

Question 5

Staphyloma

Answer 5

Deep ulcer perforating through cornea to aqueous humor, not usually related to Staph

Question 6

Pannus

Answer 6

Blood vessel formation

Question 7

Moraxella Virulence Factors

Answer 7

Hemolytic, pilliated, RTX toxin, cell detachment facor, capsule, LOS

Question 8

Moraxella Pili

Answer 8

Required for adherence, cytotoxic, types Q and I, enhances corneal pitting

Question 9

Moraxella Pathogenesis

Answer 9

Adhere to corneal epithelial cells, causes pits in cornea, leukocytes infiltrate and cause inflammation, cornea becomes opaque, ulcers develop and can rupture anterior chamber

Question 10

Moraxella Immunity

Answer 10

Strain specific antibodies to pili, IgA in lacrimal secretions, antibody to toxins

Question 11

Moraxella Vaccination

Answer 11

Only in outbreak, use strain from outbreak

Question 12

Moraxella Diagnosis

Answer 12

Eye swab on blood agar, hemolytic, oxidase positive, colonies pit agar

Question 13

Moraxella Treatment

Answer 13

Wide variety of drugs, but resistance may develop: susceptibility test needed

Question 14

Chocolate Agar

Answer 14

Blood agar that has been heated to lyse cells with heat labile factors added back