Nocardia + Dermatophilus Flashcards
General staining characteristics of Nocardia, Dermatophilus?
-Gram +ve , slow growing -Rod-coccobacillus bacteria.-Extensive branching and filamentation.
What type of lesions do Nocardia and Dermatophilus cause?
pyogranulomatous lesions
Nocardia spp. are considered to be what type of pathogen?
soil-borne
What type of pathogen are dermatophilus bacteria?
they are obligate intracellular pathogens
What is the most common species of Nocardia?
N. asteroids
Nocardia effects what species?
cattle, dogs, cats, horses and humans
Nocardia causes chronic progressive disease via what forms?
cutaneous, pulmonary, and disseminated forms
A common sign of Nocardia infection in Bovine is?
mastitis - found on dairies Entry of Nocardia via contaminated infusion equipment.
How is bovine mastitis due to nocardia treated?
Culling - No effective treatment. (novobiocin may help in early stages)
The following clinical signs in dogs and cats can be linked to infection with? -Subcutaneous and lymph node lesions (mycetomas ) -lesions in throat, abdomen, heart, brain, liver, and kidneys -Severe halitosis (bad breath), gingivitis, and ulceration of the oral cavity are common in dogs
Nocardia
Canine Nocardiosis can be confused with bot fly larvae, why?
Granulomatous swelling with discharging fistulous tracts appear like the “holes” formed from bot fly larvae
Respiratory form of Canine Nocardiosis is acquired through inhalation. How does it present?
Fluid accumulation in thoracic cavity. Fever, respiratory distress.
Disseminated form of Canine Nocardiosis presents how?
Abscesses in various organs, brain
How is Canine Nocardiosis treated?
Trimethoprim sulfate or tetracyclines (penicillin is not effective)
What dermatophilus causes skin infection of cattle, horses, sheep, goats (Occasionally dogs, cats, and humans)?
Dermatophilus congolensis
What infection is known as: 1. “Rain scald”/”Rain 2. “Lumpy wool disease” 3. “Strawberry foot rot”
Dermatophilus congolensis infection
What disease is highly predisposed due to ticks?
Dermatophilus congolensis
D. congolensis has a long development cycle. Which portions of the cycle can cause infection?
only zoospores - only a free zoospore or a mature zoospore that is released
Clinical sign of infection of D. congolensis is when you pull on the hair, the chunk of skin comes out with the hair (large patch). Why does this occur?
Due to the pathogenesis of the bacteria.
What is needed for diagnosis of D. congolensis?
Scab material stained with Giemsa showing branching filaments (Adequate for diagnosis)
D. congolensis is seen in three forms in what species?
sheep
True or false: D. congolensis is zoonotic?
true; acquired from farm animals
Diagnosis of D. congolensis requires:
Make smear from scab undersurface; stain with Gram’s or Giemsa. + ve if “railroad track” like hyphae seen.
What is used as treatment of DERMATOPHILOSIS?
-Penicillin + streptomycin or long acting tetracyclines (I.M) -in mild cases remove scabs with mild soap and clean with iodine -reduce skin trauma and control ticks
Concerning Nocardia and Actinomyces what statement is accurate? A. Chickens can get infection from both. B. Cattle do not get mastitis due to Nocardia. C. Both are gram negative bacteria D. Actinomyces bovis causes “lumpy jaw” in cattle E. Penicillin is effective against both
D. Actinomyces bovis causes “lumpy jaw” in cattle
You saw for the first time a case of “rain scald”/ streptothricosis in a horse. Which drug will you select for treatment? a. Amphotericin B b. Tetracycline c. Ketoconazole d. Griseofulvin e. Nystatin
b. Tetracycline
