Curved Bacteria: Lawsonia, Helicobacter, Campylobacter Flashcards
what pathogen causes porcine proliferative enteropathy (PPE)?
Lawsonia intracellularis
what is the morphology and appearance of Lawsonia intracellularis?
slender, curved gram-negative rods
how prevalent in Lawsonia intracellularis in swine?
present in feces of most swine herds
what are the three disease forms of Lawsonia intracellularis in swine?
necrotic enteritis
porcine intestinal adenomatosis
porcine hemorrhagic enteropathy
what does Lawsonia intracellularis cause in horses?
equine proliferative enteropathy
what age of horses are primarily affected by Lawsonia intracellularis?
weanlings 3-12 months
what clinical signs are associated with equine proliferative enteropathy?
diarrhea
rapid weight loss
colic
subcutaneous edema
lethargy
how can you diagnose Lawsonia intracellularis?
clinical signs
PCR but present in most swine herds
histopathology
immunohistochemistry to demonstrate intracellular bacteria in lesions is definitive
how is Lawsonia intracellularis treated and prevented?
antimicrobials in water and feed can reduce severity and precent chronic disease
live attenuated vaccine available and oral vaccine under evaluation
what is the morphology and appearance of Campylobacter?
thin, curved gram-negative rod
polar flagella, motile
daughter cells adhere to make chains
what causes intestinal campylobacteriosis in dogs and humans?
Campylobacter jejuni
how is Campylobacter jejuni transmitted?
fecal-oral
what is the pathogenesis of Campylobacter?
transcellular or paracellular
why is Campylobacter jejuni difficult to diagnose?
nonspecific symptoms
intermittent shedding
may be asymptomatic
what does Campylobacter fetus subspecies venerealis cause?
bovine genital campylobacteriosis
bulls asymptomatic
cows can develop mucopurulent endometritis
what is mucopurulent endometritis?
early embryonic death
abortion
variable return to fertility
how is Campylobacter fetus subspecies venerealis transmitted?
coitus
what is the most common cause of ovine genital campylobacteriosis?
Campylobacter fetus subspecies fetus
how is ovine genital campylobacteriosis transmitted?
fecal-oral
what is the aborted fetus in ovine genital campylobacteriosis usually like?
autolyzed
40% with orange-yellow necrotic foci in liver
is Campylobacter fetus zoonotic?
yes
how is Campylobacter fetus subspecies venerealis treated and prevented?
vaccinate prior to breeding season, short-lived immunity
streptomycin can clear infection in bulls
cows typically not treated
artificial insemination
how is Campylobacter fetus subspecies fetus treated and prevented?
tetracyclines may prevent exposed ewes from aborting, lots of resistance
strict hygiene
consistent vaccination, tends to run in 4-5 year cycles
what is the appearance of Helicobacter pylori and non-H pylori Helicobacter?
slender, curved, gram-negative rod
what can Helicobacter pylori cause?
gastric ulcers
what are the three categories of virulence factors of Helicobacter?
colonization
immune escape
disease induction
how prevalent is Helicobacter in dogs and cats?
up to 100% of vomiting dogs and cats
up to 100% of healthy dogs and cats
what should you consider when treating Helicobacter?
role of causative agent is unclear
combination of clinical signs of gastritis and Helicobacter presence may warrant treatment
double/triple antimicrobial plus acid suppressants for 2-3 weeks
clinical signs may improve, by difficult to eradicate
what are the virulence factors of Lawsonia intracellularis?
curved shape
obligate intracellular organism that lives in crypt epithelial cells
other factors poorly understood
what is a disease that is similar to porcine proliferative enteritis that is caused by Brachyspira hyodysenteriae?
swine dysentery
what is a concern with drugs with Campylobacter jejuni?
multidrug resistance
how many variants of Campylobacter S-layer microcapsule have been described?
eight
antigenic shift
is Campylobacter a commensal?
yes in many species
what are the causes of ovine genital campylobacteriosis?
Campylobacter fetus subsp fetus
C. jejuni
C. lari
what happens in ovine genital campylobacteriosis?
placentitis with hemorrhagic necrotic cotyledons
aborted fetus usually autolyzed
still-born lambs
Which Campylobacter species are zoonotic?
C. jejuni
C. fetus subsp venerealis
C. fetus subsp fetus
diarrhea, abortion, sepsis in humans
what is the treatment for Helicobacter?
role as causative agent unclear
double/triple antimicrobial plus acid suppressants 2-3 weeks
difficult to eradicate
only treat if clinical signs and Helicobacter present
