, lecture 10 Diseases due to spiral-shaped bacteria "spirochetes",

Spirochetes- general background, gram type? motile and if so via what?

Gram negative (have LPS)

Highly motile cells via perirlasmic flagellae (not exposed)

What are the main veterinary important spirochetes

•Leptospira

   - Leptospirosis in pigs and horses: Leptospira spp , such as Leptospirainterrogans

•Brachyspira

    - Dysentery (“bloody scours”) in pigs: Brachyspira hyodysenteriae

•Treponema (the genus that causes syphilis in humans)

   - Papillomatous Digital Dermatitis (PDD) in sheep/cattle (ruminants) : Treponema spp.

•Borrelia

   - Lyme disease in dogs & wild animals: Lyme borreliae (Borrelia burgdorferi sensu lato or Borreliella)::

Invasion of most pathogens of spirochetes are systemic or local

Systemic but there are some exceptions

Pathogen life cycle , what is the reservoir host? transmitted how? zoonotic?

Leptospira, what is the reservoir host? transmitted how? zoonotic?

Leptospira infection cycle:

-Leptospira comprise many genospecies (genetically defined), with many serovars with some “host-association.” Rodent is the reservoir hosts.

-Water-borne (transmitted via infected urine)

-Zoonoses (infect both humans and animals): One health !!!

What regions is leptospirosis mainly seen

Mostly sub-tropical/tropical regions

The hurricanes in sub-tropical/tropical countries enhance the possibility of leptospirosis prevalence?

Yes

How does leptospirosis (leptospira spp) replicate?

What is wells syndrome

the severe forms of leptospirosis

What is the main virulence factor from leptospirosis that causes pathogenesis in animals?

LPS (endotoxin): lead to severe inflammation via immune cell signaling

What is the main diagnostic test for leptospirosis

Mainly serologic test: MAT (microscopic agglutination testi)

it is high specificity, low sensitivity, cost saving)

What do the kidney values look like when an animal is exposed to leptospirosis

An eight-year old of female dog had fever, vomiting, anorexic and depressed conditions. The dog had increased liver enzyme activity and BUN and creatinine clearly, showing the hepatic and renal dysfunction. The veterinarian ordered the microscopic agglutination test (MAT) for a suspected pathogen species and found the antibody titer of that dog was 1:200 for suspected the pathogen. What could be the pathogen that veterinarian requested the MAT test for?

Leptospira interrogans

How does brachyspira contact hosts and get out from the hosts, who is the maintenance host? how is it transmitted?

Pig is the maintenance host (not necessarily reservoir)

Food and water-borne (transmitted via infected feces)

can spread from contaminated food and vehicle

Swine dysentery is caused by what bacteria?

Brachyspira spp

Is swine dysentery a systemic or local infection?

Only local

What is a symptom that swine dysentery cause?

Mucohemorrhagic colitis: hyper secretion of mucous as well as mucosal damage lead to malabsorption and mucohemorrhagic diarrhea, dehydration)

Where does swine dysentery colonize and attach

Intestines

Papillomatous digital dermatitis (pdf) is caused by what bacteria?

Treponema spp

For PDD (treponema spp) who is the maintenance hose, what is it also known as, transmitted via?

Is PDD (treponema spp.) a systemic or local infection

LOCAL ONLY

What are early stages and late stages of PDD (treponema spp)

Early: inflammatory lesions

Late: proliferate papillomatous stages, chronically thickened skin and hyperkeratosis

Lyme disease is caused by what bacteria

Borrelia burgdorferi; lyme borelliae spp)

Lyme borelliae, main reservoir hosts? transmitted how? zoonotic?

Rodents and birds are main reservoir hosts

Vector-borne (transmitted via infected tick bite,s exodus spp: hard ticks

Zoonotic: infect both humans and animals, one health??

How does Lyme borelliae enter and replicate? where is attachment at?

Colonize and attach at tick bite sites of skin (early)

disseminate/invase via bloodstream

Attach/colonize at joints (late)

What is the most common vector-borne disease in northern hemisphere?

Lyme disease (Lyme borreliae)

Prevalence of Lyme disease only where? where is the prevalence in the US?

Prevalence only in northern hemisphere

In US is prevalent in north east and upper mid-west

Is understanding the distribution of Lyme disease cases helpful for you to diagnose Lyme disease infection in animal patients?

Yes

What are the main virulence factors of Lyme borreliae that are important?

What is the main diagnostic test for Lyme borreliae

Mainly serological test: ELISA/Blotting (Two tier tests)

Not sensitive until late stages

Cannot differentiate current vs. previous infection

What is the treatment for Lyme borreliae

Antibiotics (doxycycline)

What is main prevention for Lyme borreliae

Dead bacteria vaccines

Why would one health concept be important for prevention development against Lyme disease