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24 Cards in this Set
- Front
- Back
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How do spirochetes gram stain?
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Genetically they are gram neg, but they are too skinny to visualize with gram stain.
Use: Silver staining, darkfield microscopy, and antibodies are used primarily for labeling. |
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How do spirochetes move?
What is this type of motility good for? |
Corkscrew motility - axial filaments of spirochetes
• Flagella are located in the periplasm (between the cytoplasmic membrane and outer sheath) (like an outer membrane), anchored at each end • Flagella contract to make corkscrew motion • Works best in viscous medium (that's what it's good for - getting through mucosal membranes) |
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What family of bacteria do leptospira belong to?
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Spirochetes.
(I don't know if I used family properly.) |
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What is leptospira transmitted?
What species does it colonize? |
Pathogen is excreted in urine- contaminated water can be source of infection. Enter through small _abrasions_, spread systemically.
Many species- colonizes the renal tubules_of mammals • Humans- survive days in tubules • Rodents (and other species) - lifelong |
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How many serotypes do Leptospira have?
Are Leptospira commensals? |
A lot - not as many as Salmonella, but they definitely use this technique for species survival. Different serotypes cause different types and pathogenicites of disease.
They may hang out and not do harm for a while - but they are not commensal. |
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What kind of host is humans for leptospirosis?
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Terminal, accidental host - Humans- acute disease- Liver damage… Weil’s disease
Humans get it from rodent of domestic animal urine, but they do not transmit it on. How do people get it in the U.S.? Contact with contaminated water, urine, infected animals. Mucosal contact, break in skin. Contact usually needs to be direct. (note the rafters/iron man examples though…) |
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How do cattle, sheep, horse, pigs, dogs manifest Leptospira?
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Certain strains (serovars) are species-adapted
Cattle, sheep: Abortions (not placentitis), systemic infections Horses: Many apparent asymptomatic infections. Some abortions, renal disease, immune-mediated uveitis. (moon blindness) Pigs, dogs: acute disease, liver disease, renal failure jaundice (icterus) Serious disease most common in _incidental_ hosts. |
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What are the steps of lepto infection?
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1: Mucosal contact by pathogen, entry into _bloodstream_
2: Systemic dissemination- “leptospiremia” and colonization of organs 3: Systemic clearance by _kidney_-specific antibodies 4: Colonization of kidney tubules for short or long periods Capillary damage, liver/ kidney function is impaired. |
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What is the big virulence factor of Lepto?
Is there a vaccine against it? |
Leptospira LPS is very immunogenic and antibody can be protective
Good vaccines are available. Cattle, pigs, dogs. Problem: many serotypes- serotype-specific vaccines not cross protective. Totally antibody-dependent protection, primarily IgM |
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What family of bacteria does Borrelia Burgdorferi belong to?
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Spirochetes
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What species is borrelia most common to?
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Dogs, horses most common
Signs: Painful arthritis- lameness, inflammation of several organs especially kidney- renal disease can be fatal. Avian spirochaetosis- Borrelia anserina arthropod borne- systemic disease many species affected- mortality can be high spleen/liver involvement, hemorrhage. epizootic occurance- look for borrelia in the blood. |
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What are the symptoms of Borrelia in animals? How do you diagnose it?
What are the signs? If you clear the pathogen, will you still suffer the symptoms? |
Signs: Painful arthritis- lameness, inflammation of several organs especially kidney- renal disease can be fatal. Swollen painful joints, fever, anorexia, lethargy.
Can get neurologic signs- facial paralysis, seizures. Diagnosis: commonly serology. Problems connecting disease to infection. Antibiotics can be effective. Even if the infection clears, due to the autoimmune nature of it, you can still suffer the symptoms. |
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What is the diagnostic lesion of Borrelia (lyme dz) in humans?
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Erythema chronicum migrans.
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What are some tick transmitted dz of animals?
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Anaplasmosis : cattle and sheep, deer.
Babesiosis: dogs, cattle, horses, deer. Ehrlichiosis: dogs, deer. Haemobartonellosis: dogs and cats Rocky Mountain spotted fever: dogs Lyme disease: dogs, cattle, horses, small mammals Theileriosis: white-tailed deer Hepatozoonosis: dogs, cats and small mammals. Cytauxzoonosis: cats |
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Do ticks pass Borrelia on to their progeny?
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No - usually they get it in their first host. It's infective as a nymph then and those are tiny.
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What is the tick life cycle?
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2 years- eggs are laid by adults on the ground in the
spring. Larvae hatch and find a blood meal. Usually a white footed mouse. Over the course of the next 9 months, larvae develop to nymphs. Nymphs again feed on mice. Engorged nymphs fall off and mature to adults. Adults find another host, usually a white tailed deer. Mating, feeding, female falls off and lays eggs. Most disease is transmitted to humans by the nymph (90%)- therefore mouse is most relevant to human disease. Both mice and deer are important in the tick biology. Ticks take in a blood meal, and the Borrelia that may come along. Bacteria then establish infections in the midgut and wait for the next blood meal. Upon contact with the next host, the bacterium is transmitted to the salivary glands (see drawing) and “spit” into the next host. Borrelia can also be transmitted via the feces, and may just be deposited on the skin. The individual then can introduce the bacteria by rubbing or scratching. Disease is seasonal- most transmission in summer, when people are outside and ticks are active. |
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What is the difference between transovarial and transstadial transmission?
Which does Borrelia use within ticks? |
Transovarial: generation to generation transfer.
Transstadial: transfer between _life stages_ in a single animal. Borrelia _does not_ undergo transovarial transmission at any appreciable level. (less than 1% of tick eggs acquire borrelia from parents.) |
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Is Borrelia a commensal in the tick?
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Yes.
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How does body temperature relate to Borrelia?
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The tick temp is low - when they find a host, they heat up. When the temperature rises, the bacteria changes it's OSP, from OspA to OspC, and move from the midgut to the salivary gland and is transmitted into the host.
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What is the surface protein of Borrelia?
How does this relate to vaccines? |
Borrelia has many OSP’s (_outer surface protein_). Dominant proteins found in laboratory isolates include OspA and OspB. BUT, if one looks inside the tick the picture is different. Another related protein, OspC, is upregulated within the tick and is thought to be (possibly) a major factor in transmission to humans.
Interesting concept- to protect the human you need to look at the bacteria in the tick, not just the bacteria taken from patients. Vaccine targets OspA - what is in the tick midgut, not OspC - what transmits into the host. |
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Will frontline control borrelia?
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Yes, by controlling and repelling tick infestation.
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What family is treponema a part of?
What human and rabbit disease does it cause? |
Spirochete.
causative agent of human syphilis. Other subspecies cause human diseases Yaws and Pinta. Treponema- bovine papillomatous digital dermatitis (hairy footwart) Other Treponema spp. cause “rabbit syphilis” Rabbit STI, transmision to newborns in birth canal. |
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What causes swine dystentery? What family of bacterium is it a part of?
What area of the pig does it colonize? |
Brachyspira (Serpulina)- intestinal spirochetes.
Swine dysentery, similar diseases of other animals. In pigs, disease primarily in grower/finisher pigs. Relatively uncommon in US, prevalent elsewhere. Colonizes _colonic crypts_, leads to bloody diarrhea that can be severe and fatal. Possible human connection- recent data in Bangladesh suggests that Brachyspira may be very abundant in patients considered sick from cholera. |
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What are the genome differences between the spirochetes (lepto, borrelia, treponema)?
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Leptospira: 2 circular chromosomes, full complement of genes for host-independent survival.
Borrelia: (very weird genome in a group of boring genomes - he says. Much of the genome is made up of odd genetic elements - that's all we need to know). Single linear chromosome, many weird plasmids (linear or circular), small genome, plasmids very important in multi-host infections. Treponema: Small circular genome, no plasmids, very limited metabolic capabilities, intimately associated with single host. |
