Lecture 9 Flashcards
Where are Corynebacterium & Rhodococcus normally found?
Normal component of the microbiota -skin, mucous membranes, intestinal tract
How does Corynebacterium & Rhodococcus do in the envr?
Found to survive up to 55 days in the envr
What is the biocontainment level for Corynebacterium & Rhodococcus?
2
Are Corynebacterium & Rhodococcus gram positive or negative?
Positive
Describe the metabolism of Corynebacterium & Rhodococcus
Aerobic & facultative anaerobes
What are the virulence factors for Corynebacterium renale?
Pilli (attachment)
Urease (production of ammonia)
What are the virulence factors for Corynebacterium cystitidis?
Pilli (attachment)
Urease (production of ammonia)
What are the virulence factors for Corynebacterium pilosum?
Pilli (attachment)
Urease (production of ammonia)
What is the virulence factor for Corynebacterium pseudo tuberculosis?
Phospholipase D -inhibition of neutrophils & inactivation of complement
Vasodilatory factors –> enables it to go through lymphatic sys to reach lymph nodes & replicate
What is the virulence factor for Rhodococcus equi?
VapA PRO - interferes with phagolysosome formation
What is the virulence factor for Corynebacterium diphtheria?
Diphtheria toxin - cytotoxin acting by inhibiting PRO syn
What disease does Corynebacterium pseudotuberculosis cause?
Caseous lymphadenitis in sheep & goats
Presence of pyogranulomatous abscesses of the lymph nodes & internal organs
What is the prognosis of caseous lymphadenitis?
Highly contagious & persists in the envr –> once in the herd, it is difficult to eradicate
A/bs don’t penetrate well into highly encapsulated abscesses
What disease does Corynebacterium renale cause in cattle?
Infections in the urinary tract (cystitis) & Pyelonephritis (infection of kidney)
What is the prognosis of Corynebacterium renale in cattle?
Difficult to eradicate from infected herds
Tx success decres with disease progression
More difficult to eradicate from kidney
Px worsens with increasing renal damage
How is Corynebacterium renale spread in cattle?
Maintained in herd by subclinical carriers & diseases animals
Transmission from animal to animal occurs by urine splashing onto the vulva of a susceptible cow
How do you tx Corynebacterium renale infections?
Penicillin (goes through to the urine)
What disease does Corynebacterium renale cause in sheep?
Balanoposthitis (pizzle rot) - inflammation of the penis & prepuce
What is the pathogenesis of Balanoposthitis?
Diets too high in PRO increase urea [ ] in urine
Urea is converted into ammonia by the organism
Ammonia irritates the penis
Inflammation & ulceration occurs
Bacteria enter compromised tissues & cause infection
Scarring of the prepuce prevents penile extrusion & therefore, effects breeding
How do you tx Balanoposthitis?
Combo of a/bs (definitely use penicillin)
Remove dead tissue & excess wool
Do not breed ram before healed, possible transmission
What disease does Corynebacterium auriscanis cause?
Skin infections in dogs & cats but uk if it is an opportunistic pathogen or pathogen in the wound itself
How do you tx Corynebacterium auriscanis infections in dogs & cats?
Tx may be challenging, need drugs to target all pathogens present
What disease does Corynebacterium urealyticum cause?
Rare cause of UTIs in dogs & cats
What does Corynebacterium diphtheriae cause in humans?
This is reported in animals, but more common in humans
Characteristic formation of diptheritic pseudo membrane over pharynx
What disease does Rhodococcus equi cause in horses?
Severe bronchopneumonia in young foals & abscessation in older horses
What are the symptoms of Rhodococcus equi infection in foals?
Typically present with pneumonia first
See wt loss, diarrhea & colic
In 50% of foals with pneumonia, there is enteric disease
See multi-focal ulcerative enterocolitis & typhlitis
How do horses get Rhodococcus equi infections?
Organism is acquired from the envr
Found in soils, particularly those contaminated with horse feces
Only strains containing VapA are virulent in horses, become infected by inhaling the strain
What is the prognosis of Rhodococcus equi in horses?
Fair in foals with chronic disease
Poor in foals with acute disease
What is the tx for Rhodococcus equi in horses?
A/bs
Rifampin+ macrolide type drug
Envr clean - manure, avoid overcrowding, reduce dust, provide ventilation
What disease does Rhodococcus equi cause in cats?
Rarely reported but increase
Most often cause cutaneous infections in immunocompromised animals
Lesions are characterized as pyogranulomatous inflammation (typically not painful)
Abscesses & lesions on parenchymal organs also reported
What is the tx for Rhodococcus equi in cats?
Surgical drainage of abscesses & a/bs
How do you collect C. pseudotuberculosis samples?
pus or exudates
How do you collect C. renale grp samples?
Mid-stream urine
How do you collect R. equi samples?
Trans-tracheal wash
How should the samples be handled for Corynebacterium & Rhodococcus app be handled?
Send swabs with transport media
Do not freeze
Is Corynebacterium pseudotuberculosis zoonotic?
Yes, can cause abscesses in humans (contamination during shearing)
Is Corynebacterium renale zoonotic?
Yes, but low risk to humans
Is Corynebacterium ulcerans zoonotic?
Yes, cutaneous diphtheria in people also isolated from animals
Is Rhodococcus equi zoonotic?
Rare, primarily in immunocompromised patients
What a/b is Corynebacterium app resistant to?
Fosfomycin
How should you tx Rhodococcus generally?
MLSBK + rifampin (consider rifampin toxicity in small animals)
