Moraxella Flashcards
This disease is commonly called:
* A. Pinkeye
* B. Infectious bovine keratoconjunctivitis
* C. Non-hooded eye disease
* D. A and B
* E. B and C
B
Moraxella bovis
* Appear as Gram- _______ _____
* Not true ____, cells are ___-shape around _____ disk
* Strict _____
* ___________ – oxidize organic sulfur and nitrogen (e.g. amino acids)
* 10 other species – most are commensals, but ________ and ________ sometimes cause pinkeye
negative, diplococci, coccus , rod, penicillin, aerobes, nonsaccharolytic M. ovis, M. bovoculi, Really only effects the eye
Moraxella bovis
A true coccus would be perfectly round, these are not.
Specific Disease
* Cause of?
* Results in?
* Usually more than ___% of herd infected
* May be _______ flora in _____ respiratory tract
* Transmitted by ?
* _______ and _______ required for infection
infectious bovine keratoconjunctivitis (IBK) (bovine pinkeye)
Conjunctivitis, keratitis, and corneal ulceration, 5, normal, upper, fomites, flies, or dust, Attachment, colonization
“Cattle eye infected with Infectious
Bovine Keratoconjunctivitis,
caused by Moraxella bovis.”
List the Predisposing Factors for Moraxella bovis infection?
- Sunlight (UV light)
- Breed (non-“hooded” eyelids)
- ***Flies (also involved in transmission.
- Irritation (dust, grass)
- Prior Infection
- Animals less than 2 years old most susceptible (lower
immunity?) - Transmission through direct contact with fomites
- Cattle with “hooded” eyelids most resistant
Hereford’s most susceptible
Bleeds predisposed are ones without hooded eyelids
Protect the eye from irritants
- What condition is pictured here?
- A) _____ corneal vascularization and early ____ (_____ _____) formation
- B) Pupil is ____ (_______)
- Pinkeye
- Early, pannus, blood vessel
- miotic, constricted
Corneal pannus is subepithelial fibrovascular tissue ingrowth from the _____ onto the ____. It typically results from ______, which may be causes by a number of events such as _____ or chronic ______.
limbus, cornea, inflammation, infection, irritation
This photo is showing Corneal _____ due to intraocular fluid ______.
Bright red rim of _____ formation is filling ___.
opacity, pressure, pannus, ulcer
______ is present in a localized area of corneal opacity.
Pannus formation does not occur with _______ lesions
Ulcer, shallow
A) This photo depicts a small corneal ____ due to _____ healing
B) artifact from ____
scar, incomplete, flash
Deep ulcer perforating through to the ________ ________,
referred to as a _______ (could be secondary to ___ infection).
aqueous humour, staphyloma, staph
- Healing ulcer that has lost its
red appearance
An opaque, scarred cornea and glaucoma from impaired
drainage of ______ ____
Damage to the optic nerve, which is often caused by
abnormally high pressure in the eye. Chronic inflammation
can cause such increased pressure.
aqueous humour
- Secondary infection of the
eye (endophthalmitis;
[purulent inflammation of
the intraocular fluids]) with
pus in the anterior chamber - There is pannus formation,
the cornea is white and
irregular - Sight has been permanently
lost
List the Virulence Factors of Moraxella Bovis
* The most virulent strains are known to be _____ and highly _____
* _______ is required for virulence; probably enhances _____
formation
* _________
* ___________
* ___________
* __________
* ___________
* ____________
hemolytic, piliated, Hemolysin, lesion
Pili
* Cytotoxin/hemolysin (RTX toxin)
* Cell detachment factor
* Capsule
* LOS
* Endotoxin; may act synergistically with other toxins
The most virulent strains are known to be
hemolytic and highly piliated
Pili (fimbriae) are required for ________ to cells. They are ________ and there are ____ types (?). Enhances corneal _______.
adherence, Cytotoxic, two, Q, I, pitting
Dark line = pilli
Role of capsule in disease _______, but probably a
bacterial ______ function
unknown, protective
Pathogenesis
* Bacteria adhere to ________ epithelial cells
* __________ factors and _______ cause “____” or
depressions in cornea.
* _______ infiltrate lesion and cause inflammation – _________ and ________ discharge
* Cornea becomes ?
* _______ may develop and cause rupture of the _____ chamber
corneal, Adherence, toxins, pits, PMNs , conjunctivitis, serous, hazy, edematous, then opaque, Ulcers, anterior
Immunity
* Antibodies to _____ are protective, but ____-specific
* Immunity to one strain does not prevent ________ with
another strain
* ____ antibodies are highest in lacrimal secretions, but may
still not prevent _____ disease
* Antibodies to _____ may reduce or prevent disease
pili, strain, reinfection, IgA, clinical, toxins
Vaccination
* Vaccinate only if ____ outbreak
* Usefulness ________
* Use strain isolated from ___ so pili are __________ _____
* Live vaccine best? Only ______ are available
* ______ vaccines have shown some promise, but may be too ____
* Requires about __ weeks to get protective antibodies
herd, doubtful, herd, antigenically, identical, bacterins, Subunit, specific, 4
How do you prevent a Moraxella bovis outbreak?
- “Animal management is the most effective
and economical way to prevent pinkeye. **Fly control is an extremely important part of
pinkeye prevention. Fly control methods
include using chemical insecticides, in the
form of tags, sprays, or dusts bags; and
minimizing fly populations by manure and
plant control.”
How do you diagnosis a moraxella bovis infection?
Eye swab: culture immediately to blood agar
* Gram-negative diplococci
* Hemolytic,
* oxidase +
* colonies pit agar
How do you treat a patient with a Moraxella bovis infection
- M. bovis susceptible to wide variety of drugs
- Commonly used: Long-acting tetracycline (LA-200®,
Biomycin 200®, etc.) and now tulathromycin) best;
liquamycin, florfenicol, ceftiofur, tulathromycin also
used - RESISTANCE MAY DEVELOP
OBTAIN SUSCEPTIBILITY TEST
SUMMARY
* M. bovis (ovis, bovoculi)
* Pinkeye in cattle
* Pathogenesis similar to Bordetella
Continued
* Microbiology
* Culture from lung grew large numbers of pinpoint
colonies on blood agar in 5% CO2 that failed to grow on
subculture to blood agar, but did grow well on
chocolate agar.
* Gram stain showed Gram-negative small,
coccobacilli
* Sensititre ID-Moraxella osloensis (61%)
* BioLog ID-Francisella philomiragia
- The agent responsible for this cat’s demise is most
likely: - A. Francisella tularensis
- B. Pasteurella multocida
- C. Moraxella osloensis
- D. Francisella philomiragia
- E. Bordetella bronchiseptica
PCR and sequencing of 16S rRNA gene identified
the gent as:
Francisella tularensis subsp. tularensis (type A)
Francisella tularensis
Category ___ select agent, BLS-___ pathogen
–> Distinguishing characteristics
* Gram- _________ ________
** Obligate ______
* Stain _____ with ______ stain; -___ cells
* ________ required for growth of most strains; most
will not grow on ______ agar (except F. _____)
* Requires ___-___ days for colonies to grow on media
A, 3, negative, coccobacillus, aerobe, bipolar, Giemsa, tiny, Cysteine, blood, novicida, 2-4
Specific Disease: _____
* Predominately in ____ animals
* Transmitted by ?
* Most common in _________; most animals susceptible
* ___ and ____ most common domestic animals
infected, as well as humans: ZOONOSIS
* Lesions are primarily in ______, _____, and _____
** ___________ ___________ PATHOGEN
* Tier ___ select agent
Tularemia, wild, ticks, deer fly, lice, water, and handling
infected carcass, lagomorphs, Cats, sheep, liver, spleen, lungs, FACULTATIVE INTRACELLULAR , I
Human clinical disease
Most common clinical presentation: combination of a ____ ____ and ______ of the closest _____ ______ to the area of infection.
At least ___ forms can occur based on route of transmission
* Symptoms include ?
* ________, _________, and _________ may occur with intestinal tularemia.
* If the illness continues, the infected individual will have ______, ______, and _______ get _________ weaker as well as ___ weight. Symptoms differ depending on ____ the individual is infected.
skin ulcer, swelling, lymph node, 7 , abrupt fever, headache, chills, body aches, sore throat, Nausea, vomiting, and diarrhea, sweats, fever and , lose, chills, progressively, how
What disease is pictured?
Tularemia
Francisella nomenclature
* F. tularensis subsp. tularensis (type ___; primary Tier __
bioterrorism agent) only in ______ _____ (associated with ______)
* subsp. holarctica (type ___) ________ (northern
hemisphere; also virulent, but less so that type __); associated with ____
* subsp. mediasiatica ( _____ virulent and in ____)
* subsp. novicida ( _____ virulent and may be ______- independent) ______; likely a ______ species
* F. philomiragia (relatively _______)
* ______, and ______ vector: _______ disease and ________ lesions
* Can survive in the environment for _________ periods , possibly in _____ and ______ (ticks) as a biofilm.
* HUMAN ________ PATHOGEN
A, 1, North America, land, B, worldwide, A, water, less, Asia, less, cysteine, worldwide, distinct, avirulent, Wildlife, arthropod, systemic, granulomatous, extended, water, arthropods, ZOONOTIC
List and explain the Virulence Properties of Franciesella
- Capsule (Glycoproteins)
- LPS-not an endotoxin-protective mechanism; strains
lacking O-ag are avirulent! - Invasiveness: capability to survive intracellularly
and disseminate - results in granulomatous lesions
- A pathogenicity island has been identified that is
required for intracellular survival! - Invisible pathogen: the host does not see it. LPS is not a
TL4 agonist. A cytokine storm (finally due to TLR-2 )
occurs several days after infection.
List the Compromising factors of Franciesella
- NONE NEEDED! Frank Pathogen
- Highly virulent: human infectious dose is ~10-50
organisms; BSL-3 pathogen - Exposure to infected animals
- Exposure to arthropod vectors (ticks most
common in this country) - D=NV/R ; for Ft, N=10-100 in humans; 1 in mice
Immunity to F. tularensis
* ________ immunity required for protection
* _____ response (?).
* ________ cannot reach intracellular organisms, but may
have protective potential prior to phagocytosis
* ___ cells must kill infected cells
Cellular, Th1 , TNFα, ***IFN-γ, IL-12, etc, Antibodies, T
Vaccination
* _____ vaccine no longer available for people at risk
* Vaccine not used for _____
* __________ vaccines have not protected against type A infections
* ______ cells alter their phenotype rapidly (insertion sequences in genome cause _______ and _______ in genes)
Live, wildlife, Subunit, Live, deletions, duplications
Diagnosis
* Requires _______-______-______agar (except F. novidica, which grows on ______ agar)
*___-__ days to grow
* However, need BSL-___ lab to isolate, but then must _____ isolate
* _______ (most common)
* _____
* ______
* _______ disease
cysteine, glucose, blood, blood, 2-4, 3, destroy, Serology, FA, PCR, Notifiable
Treatment for Franciesella
Streptomycin or other aminoglycoside and
tetracycline are synergistic
Combination is treatment of choice
Ciprofloxacin and some cephalosporins can be used
in humans (treatment and prophylaxis)
Avoid rabbits (especially in Martha’s Vineyard)
SUMMARY
* Invasive, granulomatous disease of wild and sometimes
domestic animals
* Intracellular
* Zoonotic
* Select Agent
