Lawsonia, Pajaroellobacter, and Vibrio Flashcards
Where does Lawsonia intracellularis survive?
intracellulary in the epithelial cells of the ileum
What does Lawsonia intracellularis cause in swine?
proliferative enteritis and related diseases (hose pipe and garden hose gut)
What are the four forms of disease in Lawsonia intracellularis?
intestinal adenomatosis, regional ileitis, necrotic enteritis, and proliferative hemorrhagic enteropathy
What is used to treat Lawsonia intracellularis infection?
a number of antibiotics
Is there immunization for Lawsonia intracellularis?
yes, attenuated live organism are currently being marketed for swine; they are administered through the water or used as a drench
What does Lawsonia intracellularis cause in foals?
proliferative enteritis
What age foals are typically infected with Lawsonia intracellularis?
3-7 months of age but older horses can develop disease
What population of foals are typically infected with Lawsonia intracellularis?
foals in poor physical condition
What history is associated with Lawsonia intracellularis infections in foals?
chronic mild diarrhea and a history of lethargy, anorexia, and weight loss
What lesions are associated with Lawsonia intracellularis infections in foals?
multifocal to confluent mucosal hyperplasia in the jejunum, ileum, and proximal colon - these areas may demonstrate variable degrees of erosion and/or ulceration
What can infection of Lawsonia intracellularis be caused by in foals?
ingestion of the organism. contact with feces of carrier animals and/or vertical or horizontal transmission in horses
What does Lawsonia intracellularis cause in hamsters?
proliferative enteritis - wet-tail (even though it can be caused by E. coli, Campylobacter jejuni, Cryptosporidium, and Chlamydia species)
How is Lawsonia intracellularis diagnosed?
growth of the organism in tissue culture or by gross lesions, immunohistochemical staining, FA test, and PCR (post-mortem)
What is the cause of ‘foothill abortion’ or epizootic bovine abortion (EBA)?
Pajaroellobacter abortibovis
What is the morphology of Pajaroellobacter abortibovis?
slow growing gram negative rod
What is the natural habitat of Pajaroellobacter abortibovis?
soft tick - Ornithodoros coriaceus
What is the pathogenesis of EBA?
Immunologically naive pregnant heifers and cows grazing around scrub brush and pine trees in endemic areas contract the organism through the tick bite. The cows and heifers do not show any clinical signs. The fetus becomes immunocompetent around the middle of gestation so if it is infection prior than that time abortion or stillbirth can result
How is Pajaroellobacter abortibovis diagnosed?
the organism can be identified by immunohistochemical staining of affected fetal tissues
Is there currently a vaccine for Pajaroellobacter abortibovis?
Yessish - an experimental live vaccine is being tested and preliminary results show it to be efficacious
What is the general morphology of the genus Vibrio?
spirally curved, gram-negative rods with varying shapes
What does Vibrio cholerae cause?
human cholera
Where is human cholera endemic?
in the Bengal region of India and Bangladesh
In lesser developed countries, what is disease from Vibrio cholerae associated with?
food and drinking water contaminated with fecal material - outbreaks are associated with consumption of raw or undercooked shellfish or crabs
What are the two important toxins produced by Vibrio cholerae?
cholera toxin and ST toxin
What is the structure of cholera toxin produced by Vibrio cholerae and what does it do?
it is a classic A-B structure toxin that stimulates adenylate cyclase - it is secreted from the bacterial cell
What disease processes are associated with human cholera?
severe diarrhea, vomitting, and abdominal cramps - there is severe water loss
When is immunization against Vibrio cholerae recommended?
when travelling to areas with outbreaks and areas where adequate safe food and water are not available
What is an essential treatment for Vibrio cholerae?
fluid replacement
What does Vibrio parahemolyticus cause?
food poisoning in humans - severe gastroenteritis
What is disease caused by Vibrio parahemolyticus associated with the presence of?
hemolysin
What is Vibrio parahemolyticus common in?
shellfish - it loves salt
