Exam 2: Gram Positive Rods Flashcards
What is Erysiopelothrix an important cause of?
Erysipela in turkeys and swine
Describe Erysiopelothrix
Non-motile Non-spore forming Non-acid-fast Catalase negative Produce H2S on TSI
What does Erysiopelothrix survive in?
Soil
What is a major source of Erysiopelothrix?
Carrier animals
What is Erysiopelothrix remarkably resistant to?
Chemicals
What are the 4 forms of diseases of Erysiopelothrix?
Acute septicemia
Urticarial cutaneous lesions, “Diamond skin” lesions
Vegetative endocarditis
Arthritis
In sheep, what do wound infections lead to with Erysiopelothrix?
Polyarthritis (“joint ill in lamb”)
Who can get occupation disease from Erysiopelothrix?
Butchers
Fish handlers
Veterinarians
What contributes to the predilection for certain tissues in subacute or chronic forms with Erysiopelothrix?
Fibrin accumulates in joints, heart valves, and arteries
What is the virulence factor of Erysiopelothrix?
The enzyme neuraminidase
What does neuraminidase do?
Removes N-Acetylneuraminic acid from many substrates and leads to anemia, leukopenia, and thrombocytopenia
What is the immunity involved with Erysiopelothrix?
Mainly humoral immunity
What vaccines are the best for Erysiopelothrix?
EVA (erysipelas vaccine avirulent) live vaccines
What is the drug of choice for treatment of Erysiopelothrix?
Penicillin
What can Rhodococcus equi cause?
Suppurative bronchopneumonia of foals 2 wks. to 5 mos., peaking at 4-6 weeks of age
How can Rhodococcus equi be acquired?
Inhalation of pathogenic R. equi in dust
What is Rhodococcus equi carried in?
The GI tract of gregarous birds
What diseases can occur with Rhodococcus equi?
Pneumonia followed by enteritis
What are probable virulence factors of Rhodococcus equi?
Cholesterol oxidase and phospholipase C
Vap A protein
What does Vap A protein do?
Interfere with phagolysosome formation
What animals are at risk of being infected by Rhodococcus equi?
Foals that produce little to no detectable γ interferon
What is the treatment for Rhodococcus equi
Use lipid soluble antibiotics that penetrate bacteria: erythromycin with rifampin
What are the 3 species of Corynebacterium that opportunistic urinary tract commensals?
Corynebacterium pilosum
Corynebacterium renale
Corynebacterium cystitidis
How is Corynebacterium renale spread?
By bull and urine
What are the virulence factors of Corynebacterium renale?
PIli
Urease
Renalin
What is Corynebacterium pseudotuberculosis?
Facultative intracellular pathogen
What does Corynebacterium pseudotuberculosis cause?
Casrous lymphadenitis in sheep/goat
Ulcerative lymphangitis and folliculitis in horses
Chronic lymphadenitis and abscesses in a variety of hosts
What are 3 diseases that are caused by Corynebacterium pseudotuberculosis?
Contagious acne
Canadian horsepox
Pigeon’s fever
What is the virulence factor of Corynebacterium pseudotuberculosis?
Phospholipase D
How can you control Corynebacterium pseudotuberculosis?
Crude vaccine
Describe Corynebacterium bovis
Commensal of bovine udder (20% of quarters)
Mild neutrophil response may protect against pathogens
Describe Corynebacterium ulcerans
Mastitis in cows
MIld to severe pharyngitis in people
Causes caseous lymphadenitis in sheep/goats
When is Listeria motile?
At room temperature but not at 37 degrees C
What are the pathogenic forms of Listeria?
L. monocytogenes
L. ivanovii
What is Listeria monocytogenes resistant to?
Freezing and high salt concentrations
What may Listeria monocytogenes survive?
Pateurization
What is the range of temperatures Listeria monocytogenes can grow under?
4-44 degrees C
What are the natural reservoirs of Listeria monocytogenes?
Soil and mammalian GI tracts
How does animal-to-animal transmission of Listeria monocytogenes occur?
Via the fecal-oral route
What kind of disease is listerosis?
Primarily a winter-spring disease of feedlot
What are the forms of disease caused by Listeria monocytogenes?
Meningoencephalitis (most common in ruminants)
Septicemia (most common in monogastric animals)
What is common with the septicemia form of Listeria monocytogenes?
Abortion and stillbirth
What is the pathogenesis of Listeria monocytogenes in the alimentary tract?
Interaction between Internalin A and E-cadherin, Internalin B, and Met
What is the internalization of Listeria monocytogenes into host cells mediated by?
InI A and InIB
How does Listeria monocytogenes escape from phagosome?
Listeriolysin O and phospholipases
What happens to actin with Listeria monocytogenes?
It is polymerized into filamentous actin by ActA
What does encephalitis or meningoencephalitis caused by Listeria monocytogenes affect?
Sheep
Cattle
Goats
Occasionally pigs
What is the most common type of listeriosis in monogastric animals?
Septicemic or visceral listerosis
What is susceptible to Listeria monocytogenes in all domestic animals, especially cattle?
The uterus
What is the immunity associated with Listeria monocytogenes?
Cell mediated
Infected animals develop both delay-type hypersensitivity and acquired CMI at the same time
How is the diagnosis of Listeria monocytogenes obtained?
Samples of lumbosacral CSF
How is listerosis confirmed?
By the isolation and identification of Listeria monocytogenes
Cold enrichment for up to 12 weeks
What is the treatment/control of Listeria monocytogenes?
Antibiotics of little value for neurologic form
Tetracyclines