What family does the genus Moraxella belong to?
Name the subgenera of Moraxella
Moraxella (rods) Branhamella (coccoid)
Moraxella Gram______? Shape?
Gram Negative, Pleomorphic -Rod short, pairs or chains
Moraxella Catalase positive/negative?
Catalase positive Sometimes catalase variable
Moraxella Oxidase positive/Negative?
What two tests are Moraxella positive for?
Catalase & Oxidase positive
Is Moraxella proteolytic?
What is the most important pathogen strain of Moraxella spp?
What disease does Moraxella bovis cause?
IBK - Infectious Bovine Keratoconjunctivitis
Most common ocular disease of cattle -Highly infectious in beef cattle -Young susceptible, lack acquired immunity
What is the most common ocular disease of cattle, and name the causative agent
IBK- Infectious Bovine Keratoconjunctivitis Caused by Moraxella bovis
What are the two most important virulence factors of Moraxella bovis?
Cytotoxin & Fimbriae
What are the virulence factors of Moraxella?
Adhesins Capsule Cell Wall Exotoxins
What do Moraxella's Adhesins target?
Adhere to special niche/ target cells -Type 4 pilus (fimbriae) -Adhere to conjunctival and corneal epithelial cells
What is different about the cell wall of Moraxella?
LPS without O-repeat unit (but still acts like LPS) Lipid A endotoxin & pro-inflammatory like normal
Name the exotoxins of Moraxella
RTX (repeats in toxin) Mbx (Moraxella bovis Toxin)
Moraxella What is the role of Mbx?
Cytotoxin (hemolytic) Pore forming toxin
Moraxella What type of cells does Mbx target?
Mbx (Moraxella bovis toxin) Specificity for: -Conjunctiva -Corneal epithelial cells -Neutrophils
Does Moraxella show susceptibility or resistance to control?
Moraxella is not that resistant to physical or chemical agents -Usually IS susceptible to antibiotics
What aspects lead to Moraxella's variability/diversity?
Pili (immunologically diverse, serological classification) Non-hemolytic variants are nonpathogenic
Moraxella: Distribution / Reservoir
Worldwide in bovine -Conjunctiva - Upper Respiratory Mucosa- Often without clinical outcomes
Moraxella: Transmission methods
Direct & Indirect contact -Flying insects & airborne transmission
Moraxella: Describe the Pathogenesis
Attachment at site & destruction of tissu (Pili, Mbx) --> Damage from Inflammation & bacterial growth (LPS, Neutrophils, Mbx)--> Environment & other pathogens collaborate in damage
What environmental agents and other pathogens collaborate with Moraxella to cause damage?
- UV radiation - Flies, dust, woody pastures - IBR (Bovine Herpes Virus) - Adenovirus - Mycoplasma - Listeria - Nematodes
What does IBK stand for and what pathogen causes it?
Infectious Bovine Keratoconjunctivitis -Moraxella bovis (M. bovis) -M. bovoculi has also been isolated
Describe the pathology of IBK
Infectious Bovine Keratoconjuntivitis -Invasion of conjunctiva leads to edema & inflammation -Mild epiphora & corneal clouding -Severe edema, opacity, ulceration, uveal prolapse, panophthalmitis (inflammation of all coats/layers of eye)
What are the nicknames for IBK? What age does it effect?
"Pink Eye" or "New Forest diseases" -Mainly in young animals
Describe the healing process for IBK
Healing of ulcers proceeds from the periphery and requires several weeks. -Central scarring persists for months
What is the Morphological diagnosis (MDx) of IBK?
Chronic purulent and ulcerative keratitis -Mild conditions are self-limiting -Losses of vision, impaired animals do not forage & lose condition
These pictures are examples of what disease?
Infectious Bovine Keratoconjunctivitis (IBK)
What aspects predispose an animal to an IBK or M. bovis infection?
-Young Bos indicus -Lack of eyelid pigmentation -Prominent eye placement -Nuisance flies -Ocular irritants of environment -Concurrent infections -Vitamin A deficiency
What vitamin deficiency can predispose an animal to IBK?
Vitamin A deficiency
What other pathogens can predispose an animal to IBK?
BHV-1 (Bovine rhinotracheitis-IBR) -Thelazia spp -Adenovirus -Mycoplasma bovoculi -Listeria monocytogenes
Name a few ocular irritants from the environment
Dust, tall grasses, UV light, cold or warm ambient temperatures
Moraxella Immunological response
Antibodies of all isotypes produced -Especially ____? -Experimental bacterins give some protection -Mainly against fimbrial proteins, Mbx
What samples are most useful to collect for Moraxella laboratory diagnosis tests?
Agent in smears of exudates -Immunofluorescence
What tests are used for diagnosing Moraxella infections?
-Immunofluorescence -Culture -Biochemical analysis -Serological & PCR
Moraxella Describe the proper culture to diagnose an infection
Lacrimal secretions in sterile water 35C in media with serum & blood ***Virulent M. bovis are fimbriate and hemolytic*** (they autoagglutinate in saline)
Moraxella: Sugar (lactose) fermentation?
How would you treat and control a Moraxella bovis infection/outbreak?
-Affected animals in dark stall free of dust & flies -Topical corticosteroids reduce inflammation (controversial) -Topical & systemic antimicrobials (Long-acting tetracycline or florfenicol) -Fimbrial vaccines possible in future