Spirochetes Flashcards by Corinne Perra

Are spirochetes considered gram + or -

Gram -

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What is the morphological appearance of spirochetes?

Slender, helically coiled, spiral organisms

Move with corkscrew or flexing motion

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T/F: spirochetes are well demonstrated with gram stain

Dark field microscopy or silver stain is better

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Where is the flagella located on a spirochete?/

Periplasmic space –> gives the coiled morphology and movement in viscous environment

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What are the members of the spirochetes

Bracyspira
Borrelia
Treponema
Leptospira (Dr Rajeev’s fav)

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What is the most prevalent and widespread zoonosis ?

Leptospirosis

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How are leptospira servers organized

Carbohydrate components in bacterial outer membrane

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The genospecies of leptospira is based on?

DNA homologs

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Where are leptospira maintained in reservoir animals?

Renal tubules

Excreted through urine

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How is leptospira transmitted?

Reservoir sp excrete in urine

Animals get it from direct contact or contaminated environment

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How does disease cause by leptospira differ between humans, livestock, and companion animals?

Humans and companion animals: flu like illness and protean manifestations
Complications from renal, pulmonary, hepatic, and CNS disease

Livestock: disease of production and reproduction

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What are the virulence factors of leptospira?

Cell associated

endoflagella
outer membrane proteins
LPS

Extracellular

hymolyins
protein cytotoxins

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What is the pathogenesis of leptospira?

Entry across mucosa -> phase of bacteremia -> colonization of proximal kidney tubules (genital mucosa)

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Pathology associated with leptospira

Acute/chronic inflammation

Bacteremic phase - intravascular haemolyis petechial heamorrhage and DIC (endotoxin release), jaundie (hepatitis), nephritis, placentitis, mastitis.

Local infections of genital tract -> infertility (salpingitis)

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Dog

PU/PD
Vomiting 
Diarrhea 
Inappetene 
Lethargy 
Abdominal pain 
Icterus

Leptospirosis

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What does leptospirosis cause in dogs?

Renal or hepatic injury -> icterus

Uveitis

Bleeding abnormalities and DIC -> pulmonary hemorrhage

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How do you diagnose leptospira infection?

Dark field microscopy
FA
PCR
Culture

Microscopic agglutination
ELISA

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What is the gold standard test for leptospira

Microscopic agglutination test

Measuring Ab titers using agglutination

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What are downfalls to microscopic agglutination test (MAT)

Difficult to standardize - lab to lab variations

Requires live cultures and technical expertise

Vaccine-induced Ab my interfere

Reported to be serovar specific but cross reactivity is common

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What are the ideal samples taken for diagnostic tests to maximize diagnosistic sensitivity for leptospira ?

PCR/FA - blood or urine

MAT - serum

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How is leptospira treated?

Supportive therapy

Antimicrobial s

Penicillins -acute disease
Doxycycline - post exposure prophylactic/minimize carrier state

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How do we prevent leptospira ?

Vaccination

Minimize exposure to surface waters contaminated by reservoir hosts

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What leptospira serovar is host adapted to cattle resulting in reproductive failure

Leptospira borgpetersennii

-> embryonic death and repeat breeding

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Cattle

High fever, hemolytic anemia, hemoglobinuria, jaundice, pulmonary congestion, meningitis, and death

Leptospirosis

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How should you collect your sample for leptospira testing?

Urine mid stream for FA/PCR Overnight shipping under refrigeration conditions Serum for MAT

How should you treat and prevent a leptospira infection in the ruminants?

Long acting tetracycline s Sustained-release ceftiofur Vaccine for L. Borgpetersenii

What are the most commons serovar of equine leptospirosis?

L Pomona | L grippotyphosa

What is most commonly seen in horses with leptospirosis ?

Abortions Systemic illness in foals -> hemolysis, vasculitis with petechial hemorrhanges, hemoglobinuria, anemia, icterus, and conjunctival suffusion

What leptospira serovar are seen in pigs

Pomona | Bratislava

What does leptospirosis cause in pigs?

Reproductive failure -> infertility and abortion

________________ serovar is endemic in California sea lions

Leptospira Pomona

What are the symptoms of leptospira in humans

Influenza like (mild- subclinical) Hepatic and renal failure (Weil's disease) or pulmonary hemorrhage (severe)

Treponema is transmitted how?

Sexually

What does treponema cause in humans

Syphilis

What disease does treponema cause in cattle?

Papillomatous digital dermatitis (PDD) AKA hairy heal wart / strawberry foot disease

Economic loss from treponema is due to ?

Decreased milk production, lower reproduction efficiency , and premature culling

How do we treat papillomatous digital dermatitis?

Spray feet with antibiotic Formaldehyde foot bath - can lead to resistance or toxicity

What causes rabbit syphilis or vent diseases?

Treponema paraluis-cuniculi

What lesions are seen from treponema paraluis-cuniculi?

Perianal and facial lesions | Epidermal hyperplasia with erosion and ulcer

How is treponema paraluis-cuniculi spread?

Direct or venereal contact

What are the species of brachysprira?

B. Hyodysenteriae -swine B. Pilosicoli -animal and human ``` Role in disease is controversial B. Intermedia B. Mudochii B. Innocens B. Canis ```

What are the oxygen requirements of Brachyspira hyodysenteriae?

Anaerobic

T/F: brachysprira hyodysenteriae is an obligate pathogen and survives poorly in the environment

True

What are the virulence factors of brachyspira hyodysenteriae?

Cytotoxin, hemolysin, and LPS

How is brachysprira hyodysenteriae transmitted?

Fecal-oral Mechanical vectors Asymptomatic carrier pigs are the most important mode of transmission from farm to farm

Pathogenesis of brachysprira hyodysenteriae

Attracted to hog mucin-> invades intestinal crypts -> erosion of superficial epithelium -> mucus production, edema, and hemorrhage -> pseudomembrane -> death due to dehydration and absorption of extotoxins

What lesions are seen due to brachysprira hyodysenteriae ?

Fibronecrotic pseudomembranous colitis -> cecum and colon

Clinical signs seen with brachysprira hyodysenteriae ?

Bloody diarrhea, dehydration, weight loss Morbidity high Mortality 40%

How do you diagnose brachysprira hyodysenteriae ??

Direct stain- wright's or victoria blue Anaerobic culture PCR Histopathology and silver staining Have do differentiate from salmonellosis

How do you treat and control brachysprira ?

SPF herd Hygiene Rodent control Antimicrobials Recovered pigs develop immunity Whole cell bacteria vaccine available

What type of chromosome does Borrelia have?

Linear

What are the oxygen requirements of borrelia?

Microaerophilic (growth in specialized media)

Borrelia burgdorferi causes what disease?

Lyme disease

What is the vector of lime disease?

Ixodes tick

Who is the host of Lyme disease?

Human, dog, horse, cattle, sheep

T/F: lime disease is geographically and seasonally limited

Virulence factors of Borrelia

LPS - variation of outer surface lipoprotein (OSP) OspC to OspA -> midgut of tick OspA to OspC -> salivary gland of tick OspC -> mammals

How is borrelia burgdorferi transmitted?

Tick infected when animal has sufficiently high viremia Up-regulation of outer surface protein Midgut of tick -> salivary gland Transmission requires 50hrs

Pathogenesis of borrelia burgdorferi ?

Inoculation of skin -> multiply in skin -> bloodstream -> skin rash -> joints, brain, nerves, eyes, heart, liver, and kidney (Incubation time 2-6months)

What are the clinical signs of canine Lyme disease

Subclinical in 95% of dogs Fever, acute arthritis, arthralgia, and lameness Sometimes with anorexia, lethargy and depression

How do we diagnose Lyme disease?

SNAP test Western blot ELISA - dog and horse Paired titer Culture -> slow

How should you interpret a test where the dog has clinical signs and tests negative for Lyme disease ?

Evaluate for underlying disease and retest

How should you interpret a positive test result for Lyme disease but the dog has no clinical symptoms?

Likely to have subclinical infection Endemic area-> treatment preferred Non endemic-> no treatment

How do you treat Lyme disease?

Doxycycline Vector control Vaccine for dogs - reduced disease but does not prevent infection