Erysipelothrix, Corynebacterium, Rhodococcus Flashcards
Genus Erysipelothrix
Produces erysipeloid disease thats zoonotic and occupational
Humans acquire after direct contact
Important species under Erysipelothrix
E. rhusiopathiae **
E. tonsillarum (clinical disease)
E. inopinata
E. rhusiopathiae
Gram +, filamentous, urease and catalase -, non spore forming, H2S production
Anaerobe that grows with glucose in 5-10% CO2
What is E. rhusiopathiae survival
Resistant to drying, withstands salting, pickling and smoking
Survives 6 months in swine feces, fish slime at cool temps
E. rhusiopathiae distribution
Sewage, surface slime of fresh and saltwater fish and soil
___________ most prominent reservoir for E. rhusiopathiae
SWINE
Transmission of E. rhusiopathiae
Ingestion of contaminated material and arthropod bites (open wound for bacteria to invade)
In people that handle meat (butcher, farmer, etc)
E. rhusiopathiae septicemic infection in swine
Acute form
Causes vomiting, stiff gait, palpable skin, high mortality if untreated
Smooth colonies
E. rhusiopathiae skin form in swine
Mild red to purle rohboidals “Diamond skin lesion” with mild fever
E. rhusiopathiae chronic form in swine
Localization
Endocarditis, polyarthritis, stiffness, enlargement of joints, abortion
Forms rough colonies
E. rhusiopathiae in birds
Septicemic from in turkeys, cyanotic skin , droopy and death
E. rhusiopathiae in sheep
Polyarthritis in common
E. rhusiopathiae in dogs
Arthritis and endocarditis
E. rhusiopathiae in humans
Erysepeloid infection of the skin and subcutis
How are E. rhusiopathiae organisms grouped
A (acute) or B & N (chronic)
Based on agglutination detection of somatic Ag
What treats E. rhusiopathiae?
Penicillin in swine and turkeys
Vx
Hyper-immune equine serum for therapy if outbreak occurs
What antibiotics is E. rhusiopathiae resistant to?
Sulfonamides, aminoglycosides and vancomycin
Genus Corynebacterium
Catalase and Gram +, pleomorphic, non-spore forming, nonmotile and branching
Occurs in paralel or “Chinese letters” called diphtheroid
Prominent Corynebacterium pathogens
C. pseudotuberculosis and C. renale (C. pilosum and cystitidis)
C. pseudotuberculosis
Worldwide and found in equids, sheep, goats, cattle, buffalo, camelids
Direct contact and aerosol transmission
Soil dwelling
Portal of entry is wounds
Ulcerative lymphangitis and ventral abscess (Pigeon Fever in Horses)
3 forms:
1. Ulcerative lymphangitis/ limb infection
2. External abscesses
3. Internal infection
C. (ovis) pseudotuberculosis
In sheep and goat an agent of caseous lymphadenitis with chronic abscess of peripheral LN
Metastitic lesions with thin ewe syndrome
What does C. pseudotuberculosis cause in bovine?
Abscess and mastitis
Treatment of C. pseudotuberculosis
Lancing and draining, surgical excision, formalin injection of lesions, systemic and intralesional antibiotics
Culling/ segregation
Equine abscess= surgery + penicillin
What diseases does the C. renale group cause?
Contagious bovine pyelonephritis
Urethritis and pyelonephritis
Ulcerative posthitis in bulls and adult wethers
Vulvitis in ewes
Genus Rhodococcus
Pleomorphic, Gram + bacilli, non spore forming, intracellular anaerobic, catalase +
R. equi agar appearance
Produces mucoid colony on blood agar = Milk- drop appearance
R. equi’s ___________ produces synergic hemolysis with _________ and _________
- cholesterol oxidase
- S. Aureus
- C.pseudotuberculosis
R. equi morphology
Encapsulated and weakly acid fast (mycolic acid)
Where is R. equi present?
Large numbers in feces of healthy foals and older horses
Infection by R. equi
Acquired via inhalation of dust
Foals (<6 months) get bronchopneumonia
Abscess in cats, caprine, ovine, canine, crocs, seals
R. equi in horses
Ulcerative lymphadenitis
R. equi in bovine and pigs
B: Ulcerative lymphangitis
P: Cervical lymphadentitis
R. equi in humans
Pyogranulomatous pneumonia in patients with AIDS
Diagnosis of R. equi
Culture of tracheal aspirates, broncho-alveolar lavage and pus
PCR
Thoracic radiographs (lung)
Treatment for R. equi
Hyperimmune era @ 2-3 weeks
Clarithromycin and rifampin (penetrate macros)
