Spirochaetes: Leptospira Flashcards
Leptospira is a gram _____ bacteria
Negative
[Motile by flagella in periplasmic space, also axial filaments/endoflagella]
[capable a movement in high viscosity environments due to translational, rotating and flexing motion]
What are the two species of Leptospria that are divided based on phenotype? What is clinical ID and management based on?
L. biflexa = free-living saprophyte
L. interrogans = animal parasites
Clincial ID and management has always been based on serovar
True/False. Serovar and species concept are always in agreement.
False. Serovar and species concept not always in agreement.
Isolates of one serovar may belong to different genomospecies.
Isolates of one genomospecies may belong to different serovars.
What are the different types of serovars of Leptospira based on?
> 250 serovars based on carbohydrate of the bacterial lipopolysaccharide
(~22 genomospecies, idk if this matters)
Which species of Leptospira have serovar Hardjo?
L. borgpetersenii
Where is the pathogenic species maintained in reservior animals of Leptospira?
Renal tubules or genital tract
[Reservior hosts excrete the bacteria through urine and contaminate the enivroment/water]
Which species of Letospria have serovar Grippotyphosa?
L. kirschneri
How is Leptospira transmitted?
Direct contact with urine or contaminated water results in infection in susceptible hosts
[Reservior hosts excrete the bacteria through urine and contaminate the enivroment/water]
True/False. Pathogenic species of Leptospira can survive for long periods of time in the environment.
False. Pathogenic species survive for short period of time in ponds, rivers, surface waters, moist soil, mud
[survival prolonged at lower temperatures and near neutral pH]
Which species/reservior host is the greatest zoonotic threat?
Rats
Will you see clinical signs of Leptospira in reservoir hosts?
No
Asymptomatic or mild illness
Maintain organisms in kidneys
Shed high numbers of organisms in urine
Negative to low titers
Will you see clinical signs of Leptospira in an incidental host?
Yes
Symptomatic for disease
High antibody titer
Do not maintain organism in kidneys
Minimal zoonotic risk from dogs
Which species is the maintence host for pathogenic Leptospiral serovar Canicola infect?
Dogs
Which species is the maintence host for pathogenic Leptospiral serovar Pomona infect?
Pigs, cattle, opossums, skunks
Which species is the maintence host for pathogenic Leptospiral serovar Grippotyphosa infect?
Raccoons, muskrats
Which species is the maintence host for pathogenic Leptospiral serovar Hardjo infect?
Cattle, sheep
Which species is the maintence host for pathogenic Leptospiral serovar Icterohaemorrhagiae infect?
Rats
Which species is the maintence host for pathogenic Leptospiral serovar Bratislava infect?
Pigs, maybe mice, maybe horses
What is the difference between a maintaince host and incidental host?
Maintence hosts will be asymptomatic and shed the organism long term due to being in the kidneys.
Incidental hosts will show symptoms of disease. If the animal is able to recover it will only shed the organism short term in urine.
What is the type of infection that is caused by leptospira?
Biphasic infection
Acute stage (in blood) and convalescent stage (in organs)
What are the clinical signs would you expect to see in a dog with Leptospirosis?
Hepatic failure, including icterus
Pancreatitis
Bleed abnormalitis and DIC
Acute renal failure
Chronic infections: may culminate in signs of decompensated chronic kidney disease
Can you diagnose a patient with Leptospirosis based on the clinical signs alone?
NO! No presentation of leptospirosis is diagnostic; clinical suspension must be confirmed by laboratory testing.
Which test is used as the gold standard to diagnose leptospirosis?
Microscopic agglutination test
[measures antibody titers to Leptospira serovars using an agglutination test which uses live Leptospira serovars]
Is it easy to distinguish between vaccinated, acutely infected and recovered animals?
No. It is not.
Is the MAT a great gold standard test? What other tests could you use?
No, it is not. Lots of things are issues.
“Our findings show that culture plus MAT is an imperfect gold standard against which to compare alternative tests for the diagnosis of leptospirosis”
PCR (eh), ELISA (less specific than MAT), Direct Fluorescent Antibody Staining (inexpensive), culture (suck)
What are the samples that should be sent to the lab for PCR, FA, and MAT?
Which antibiotic therapy do you use for dogs infected with Leptospirosis?
Doxycycline - to minimize carrier state
Penicillins - during acute disease
Can you use agglutinating antibody titers predictive of protection or urinary shedding from/of Leptospira?
Due to specificity, cross reactions and weak reactivity of some serovars, agglutinating antibody titers ARE NOT predictive of protection or of urinary shedding.
Can you vaccinate for Lepto?
Incidental infections with serovar Pomona results in severe acute disease in which species?
Cattle and ruminants
Clinical signs include high fever, hemolytic anemia, hemoglobinuria, jaundice, pulmonary congestion, occasionally meningitis and death reported
In lactating cows, incidental infections may be associated with agalactia with small quantities of blood-tinged milk
Which species of Leptospira is host adapted in cattal and results in reproductive failure?
L. borgpetersennii serovar hardjo
Early embryonic death and repeat breeding
How would you diagnose Leptosporosis in a cow?
The same way in the dog
MAT, FA, and PCR
Samples of urine and serum
How would you treat a cow infected with Leptospirosis?
Long acting tetracyclines
Vaccination and treatment with tetracyclin is recommended in dry cows
What is the most effective approach to control of Leptospira borgpetersennii?
In general, annual vaccination of all cattle in a closed herd or low incidence area, or twice-yearly vaccination in an open herd or high incidence area, is the most effective approach of control
Which servoars are the most common causes of equine leptospirosis in US and Canada?
Pomona and Grippotyphosa
Which serovar are European horses thought to be a maintenance host for Leptospira?
Bratislava
Also reported in the USA
What are the clinically signs most commonly assocaited in horses with leptospirosis?
Abortion
Systemic illness in foals
Recurrent Uveitis
Renal failure and hepatopathy may also occur
Which Leptospiral serovars infect pigs? What are the clinical signs?
Pomona and Bratislava
Reproductive failure as evidenced by infertility and sporadic abortion
Abortions occuring 2-4 weeks before term are the most common manifestation of leptospirosis in pigs
