Trueperella, Rhodococcus, Listeria, Erysipelothrix Flashcards
what phylum do Trueperella (Arcanobacterium) pyogenes and Rhodococcus equi belong to?
Actinobacteria
what phylum do Listera spp. and Erysipelothrix rhusiopathiae belong to?
Firmicutes
Trueperella spp.
gram - ?
morphology - ?
spore - ?
gram - positive
morphology - bacilli
spore - non-spore forming
Are trueperella spp. commensal or parasitic? what part of the body?
commensal - mucous membranes of mammals
what bacteria inhabits the upper respiratory, urogenital, and GI tracts of ruminants, swine, and other mammals and is a Actinobacteria?
Trueperella pyogenes
How does Trueperella pyogens become an opportunistic pathogen that causes disease?
traumatic inoculation, secondary infection
what type of lesions does T. pyogenes cause? where?
suppurative in many organs/tissues
what virulence factors does T. pyogenes have?
pyolysin O - cytotoxic to macrophages, neutrophils, RBCs
Neuraminidase - binds to host cell and extracellular matrix
what pathogen acts a synergistic pathogen in bovine liver abscesses?
T. pyogenes
How is T. pyogenes spread throughout the body?
Hematogenous dissemination
How does an infection with T. pyogenes present in swine?
septic arthritis - often after farrowing
How does an infection with T. pyogenes present in cattle?
severe mastitis - often heifers and dry cows
what is this cow most likely infected by?
T. pyogenes
How is T. pyogenes transmitted?
horn flies, teat contact with contaminated environment or contaminated milking equipment
How is T. pyogenes diagnosed?
presumptive - clinical findings and gram + rods in exudate smear
definitive - culture & species ID of bacterium from clinical samples
What type of T. pyogenes infections do not respond well to antibiotics?
in vivo (abscess encapsulation)
what are the reservoirs of Rhodococcus equi?
soil and intestinal tracts and feces of healthy animals
what age of horses is Rhodococcus equi primarily an opportunistic pathogen?
young foals
what does R. equi cause?
granulomas, pyogranulomas, and abscesses
What is the significance of Vap proteins in R. equi?
protect against phagocytic killing
survive and grow inside macrophages (facultative intracellular pathogens)
How do foal’s lungs infected with R. equi present?
pyogranulomatous bronchopneumonia
Is R. equi infection limited to the lungs?
No - lesions can occur in pulmonary lymph nodes, mesenteric lymph nodes, intestines, and other extra pulmonary sites
How is R. equi diagnosed?
presumptive - history, clinical findings, gram + pleomorphic cells within macrophages
definitive - culture and ID bacterium (molecular ID looking for vapA gene)
what is a findings in a tracheal wash that would indicate an infection with R. equi?
gram + pleomorphic cells within macrophages
what is the PCR for R. equi looking for?
vapA gene
what strain of Listeria causes septicemia, abortion, and CNS infections in mammals?
L. monocytogenes
what is the transmission of L. monocytogenes?
ingestion of contaminated food and vertical transmission in utero
what are virulence factors of L. monocytogenes?
adhesins, listeriolysin O, grow inside phagocytic and non-phagocytic cells
what is the toxin produced by L. monocytogenes? what does it do?
listeriolysin O - lets bacteria break out of phagocyte and spread to other cells
what is the benefit of L. monocytogenes transferring cell to cell?
reduce exposure to humoral defenses
How is Listeriosis diagnosed?
Presumptive - gram + rods in smears
Definitive - culture and ID bacterium
This calf is experience facial drooping, excess salivation, and leaning to one side- what is wrong and what caused it?
brainstem encephalitis due to listeriosis
what is the most important reservoir of Erysipelothrix rhusiopathiae?
swine - tonsils and GI tracts
How is Erysipelothrix rhusiopathiae spread?
ingestion of contaminated food or water, entry via skin wounds
Where does Erysipelothrix rhusiopathiae normally persist?
organic matter in soil and water
what are the virulence factors of Erysipelothrix rhusiopathiae?
Neuraminidase - adherence to endothelial cells
Hyaluronidase - invasion of tissue
capsule - survive and grow inside macrophages (facultative intracellular pathogens)
what is the causative agent?
Erysipelothrix rhusiopathiae
How does acute vs chronic Erysipelothrix rhusiopathiae present?
acute - severe septicemia, skin lesions, high mortality, abortion
chronic - arthritis, endocarditis
Veterinarians handling what animals are at risk for Erysipelothrix rhusiopathiae?
fish, poultry, swine, and agricultural industries
How does Erysipelothrix rhusiopathiae present in humans?
localized cellulitis
How is Erysipelothrix rhusiopathiae diagnosed
presumptive - clinical findings, gram + short to filamentous rods in tissue smears
definitive - culture and ID bacterium
what is another animal besides swine that can be affected by Erysipelothrix rhusiopathiae? what happens?
poultry (esp turkeys) - acute septicemia with sudden death
