Fusobacterium Flashcards
Fusobacterium = ?
fusiform, meaning spindle shaped
Fusobacterium are
obligate ______, Gram- ______, _____ rods
anaerobic, negative, filamentous
Fusobacterium are apart of the phylum _______.
Fusobacteria
Fusobacterium have a _____ morphology
pleomorphic
Fusobacterium produce ?
butyric acid
Fusobacterium are sensitive to _______.
kanamycin
Fusobacterium are resistant to _______.
vancomycin
Fusobacterium are apart of the ____ flora at ______ sites of the ___, ____ tract, and _____ cavity.
normal, mucosal, gut, urogenital, oral
Some strains of Fusobacterium are considered to be opportunistic pathogens. List the strains that fall under this category.
- F. nucleatum (humans) = one of the most commonly bacteria in humans
- F. canifelium (dogs, cats) = isolated from bite wounds caused by dogs adn cats
- F. necrophorum (sheep, cattle)
F. necro = most important species
Name this bacterium. Describe its morphology.
Fusobacterium
Pleomorphic, gram-negative, filamentous rods.
Name the diseases associated with F. nucleatum
Cause various disease in natural habits including: oropharyngeal, GI tract, urogenital, other.
Fusobacterium necrophorum
1. Name the Subspecies (Biotypes)
2. Necrobacillosis in humans: _______ syndrome
3. A major cause of _______ in animals:
- Calf _____
- Liver ______
- _____
- _____ disease (_____)
- (a) F. necrophorum subsp. necrophorum (biotype A): virulent
(b) F. necrophorum subsp. funduliforme (biotype B): less virulent
Biotype B is more common in humans
Biotype A ? - Lemierre’s
- necrobacillosis, diphtheria, abscess, Footrot, Uterine, Metritis
F. necrophorum causes ______ infections. Name the associated pathogens, whether they are gram-positive or gram negative, and if they are a facultative or obligate anaerobe.
Polymicrobial
- Trueperella pyogenes (Gram-positive, facultative anaerobe)
- Porphyromonas levii (Gram-negative, obligate anaerobe)
- Prevotella melaninogenica (Gram-negative, obligate anaerobe)
- Dichelobacter nodosus (Gram-negative, obligate anaerobe)
Name the virulence factors of F. necrophorum and their function(s)
- Attachment to host cells
- Hemagglutinins
- Pili
- Outer membrane proteins (FomA) - Toxins
- Leukotoxin (lysis of leukocytes) *MOST important**
- LPS (endotoxin)
- Hemolysin (lysis of erythrocytes)
- Dermonecrotic toxin (lysis of collagen)
How would you diagnose a patient with F. necrophorum?
- ____________ culture: on _________ media under _________-free
condition at 37°C for ≥24-48 hrs
- _______ agar supplemented with _______ and vitamin _____
- _____________ selective agar (FSA) - Molecular analysis
- ______ (______ gene)
- Anaerobic culture: on enriched media under oxygen-free
condition at 37°C for ≥24-48 hrs
- Blood agar supplemented with hemin and vitamin K1
- Fusobacterium selective agar (FSA) - Molecular analysis
- PCR (lktA gene)
Name the two forms of media pictured and what they are used for specifically in relation to diagnosing F. necrophorum in a patient.
How would you treat a F. necrophorum infection?
- Surgical intervention
- Antibiotic therapy
- suggested drugs include: Penicillin G, Sulfonamides, Metronidazole,
Ampicillin, Florfenicol, Ceftiofur
Calf diphtheria
1. Definition?
2. Synonyms?
3. Affected host?
4. Name the two forms of Calf diptheria.
- An ulcerative necrosis of the cheek, tongue, pharynx,
and larynx caused by Fusobacterium necrophorum - Oral necrobacillosis
- Necrotic pharyngitis or laryngitis
- Oral necrobacillosis
- Calves under 3 months of age
- Oral form (Necrotic stomatitis): Ulceration of oral mucosa and
swelling of the cheek
- Laryngeal form (Necrotic laryngitis): Ulceration of the larynx
- Oral form (Necrotic stomatitis): Ulceration of oral mucosa and
What bacterial infection is this calf suffering from? Name the key clinical signs pictured.
Oral form of calf diptheria.
What bacterial infection is this calf suffering from? Name the key clinical signs pictured.
- Clinical features: Stridor and difficulty feeding
- Postmortem examination: caseous necrosis, soft tissue swelling.
Describe the development of calf diphtheria.
List the clinical symptoms of calf diptheria. What would happen if left untreated?
–> Clinical symptoms:
- Fever, depression, anorexia, excessive salivation, painful coughing,
a foul smell from the mouth, and dyspnea (hard breathers),
difficult swallowing
- Pneumonia (if untreated)
Describe what you would see on necropsy in a case of calf diphtheria.
Necropsy lesions:
- Caseous necrosis and soft tissue swelling of the larynx and vocal
cords
What would be seen on bacterial culture in a case of calf diptheria?
Bacterial culture:
- Identification of F. necrophorum often with Trueperella pyogenes
from laryngeal swabs from animals with clinical laryngitis
How would you treat your patient suffering from Calf diphtheria?
- Systemic administration of sulfonamides or tetracyclines
alone or in combination - Early treatment is more effective
- Nonsteroidal anti-inflammatory drugs (NSAIDs) may be
helpful
What is the causative agent of liver abscesses in feedlot cattle?
Causative agent: F. necrophorum
- together with Trueperella (formerly, Arcanobacterium) pyogenes
Name the affected host of liver abscesses.
Feedlot cattle (rarely feedlot lambs).
Describe the pathogenesis of liver abscesses
Describe the clinical signs associated with liver abscesses
–> No clinical signs
- Reduced feed intake
- Weight loss
How do you prevent the development of a liver abscess?
Prevention
1. Vaccine
2. Antibiotics (tylosin, chlortetracycline)
3. Nutritional management
How would you treat a patient suffering from a liver abscess?
Treatment
1. Procaine penicillin G
2. Oxytetracycline
3. Ampicillin trihydrate
Describe what can be seen in this image?
Liver abscess - cattle
Describe what can be seen in this image.
Multiple caseous nodules on liver - lamb.
Define bovine footrot.
An infectious disease characterized by inflammation of the foot
and subsequent lameness
List the causative agents of bovine footrot.
Causative agents:
1. Fusobacterium necrophorum
2. Porphyromonas levii
3. Trueperella pyogenes
List the symptoms associated with bovine footrot.
Symptoms:
1. Lameness
2. Swelling of the interdigital space
3. Loss of appetite
4. Fever, pain
5. Necrotic lesions with a foul odor in the interdigital space
6. Chronic arthritis if untreated
What can be seen in this image?
Bovine footrot
Diagnosis of bovine footrot is based on?
Clinical signs, foot examination
How would you treat a patient suffering from bovine footrot?
- Systemic antibiotics labeled for footrot
- Removal of the necrotic tissue with a topical antibiotic
- Footbaths containing agents such as zinc sulphate
How can you prevent the development of bovine footrot?
- Environmental hygiene
- Good nutrition with vitamin A, D, zinc, etc.
- Keeping the foot clean and dry
- Removal of sources of injury
- Footbaths with an antiseptic and astringent solution
Define Thrush in horses (_____)
hoofrot
A chronic disease caused by F. necrophorum infection in the frog
What are the clinical signs associated with hoofrot?
Clinical signs:
- A foul-smelling discharge in the frog (often black in color)
- Loss of frog shape
- Tenderness in the frog
- Lameness
How do you treat a horse with footrot?
Treatment: Debridement, footbaths, antibiotics
What can be seen in this image?
The frog of a horse’s hoof
Metritis in dairy cows is defined as?
An inflammation of the uterus within 21 days postpartum
What are the clinical symptoms associated with Metritis in dairy cows?
Clinical symptoms
- An enlarged uterus
- A fetid watery red-brownish uterine discharge
- Fever (RT ≥39.5°C)
- Reduced milk production
What can be seen in this image?
Metritis in dairy cows
- A fetid watery red-brownish uterine discharge
Usually diagnosed within 10 days of postpartum.
Infection persist beyond three weeks postpartum
Describe the uterine discharge scoring system for
diagnosis of metritis
Metritis in dairy cows is caused by a _______ infection. List the associated bacterium.
polymicrobial
- Fusobacterium necrophorum
- Bacteroides pyogenes
- Porphyromonas levii
- Helcococcus ovis
List the outcomes of metritis in dairy cows?
- Reduced milk production
- Reduced reproduction
- Increased culling
How would you treat a dairy cow suffering from metritis?
Antibiotic treatment
- Ceftiofur
- Ampicillin
- Oxytetracycline
Necrotic rhinitis in young pigs is a condition characterized by?
A chronic inflammation of the mucous membrane of the nose
What is the causative agent of necrotic rhinitis in young pigs?
F. necrophorum
What are the clinical signs of necrotic rhinitis in young pigs?
- Necrosis of the snout
- A foul smelling nasal discharge
- Swelling of the face
- Sneezing
How would you treat a young pig suffering from necrotic rhinitis?
Sulfonamides
How does necrotic rhinitis differ from atrophic rhinitis?
Dichelobacter nodosus is a gram-_____, non-____, obligate _______ ____. It belongs to the phylum ________ and, along with ______ _____, is a major cause of ____ in sheep and goats
negative, motile, anaerobic, rods, Proteobacteria, F. necrophorum, footrot
Name the virulence factors of Dichelobacter nodosus
- Type IV fimbriae (fimA)
- Production of serine proteases
Dichelobacter nodosus
How would you diagnose a patient with footrot?
