Order Spirochaetales

Question 1

What are the two families of importance in the Order Spirochaetales?

Answer 1

Spirochaetaceae and Leptospiraceae

Question 2

Describe the morphology of Spirochaetales?

Answer 2

Protoplasm cylinder: includes the cytoplasm of the organism and accompanying cytoplasmic membrane
Cell wall: surrounds the protoplasm cylinder
Periplasmic flagella: attached to the protoplasmic cylinder and are inserted on both ends of the cell and overlap
Outer sheath: envelope covers all of the above

Question 3

Do these stain well?

Answer 3

NO; they need a Darkfield or a phase-contrast microscopy

Question 4

What was the only genus of things that we talked about for Spirochaetales?

Answer 4

Leptospira

Question 5

Each species of Leptospira have several _____ and the basic taxonomic unit of Leptospira is the ______

Answer 5

Serovar

Serovar

Question 6

What is the morphology of Leptospira?

Answer 6

Motile, spiral rods, with one or both ends hooked.

More tightly coiled than any other spirochaetes.

Question 7

Growth of Leptospira prefers what?

Answer 7

Microaerophilic conditions

Occurs below the surface of semi-solid agar

Question 8

What is the area of growth below the semi-solid agar called?

Answer 8

Dinger zone

Question 9

Leptospira utilizes what for carbon and energy sources?

Answer 9

Long chain fatty acids and alcohols

Question 10

What are some of the virulence factors Leptospira uses?

Answer 10

Viscotaxis

Cytotoxic factor: resists killing by neutrophils and complement

Question 11

What is the natural habitat for Leptospira? Where is it often shed? How is it transmitted?

Answer 11

Proximal convoluted tubule of kidney
Shed in the urine
Direct contact with the urine or indirectly via contamination of water and food with urine

Question 12

Where is leptospira most common?

Answer 12

Warm, moist environments

Question 13

T/F Leptospira only requires a few seconds of contact time to penetrate mucous membranes

Answer 13

TRUE; can penetrate membranes of eyes, skin, nose, or mouth

Question 14

What are the two different kinds of hosts when it comes to Leptospirosis?

Answer 14

Maintenance and Incidental

Question 15

Describe what different effects the maintenance and incidental hosts will encounter with Leptospirosis?

Answer 15

Maintenance: do not usually become clinically ill. Antibody titers are never high and fall quickly. Can shed organism for a long time.
Incidental: high fever and acutely ill. Develop high antibody titers and shed for a time, but are not long term shedders

Question 16

What kinds of clinical illness will you see in incidental hosts?

Answer 16

Acute hepatitis resulting in jaundice
Acute nephritis that can turn to chronic; common in dogs
Abortion, specifically when infected during last trimester

Question 17

What are some of the resevoirs for some of the Leptospira serovars we are concerned with?

Answer 17

Icteroheamorrhagie: rats
Canicola: dogs
Pomona: swine
Hardjo: cattle

Question 18

What are the common signs of Leptospirosis in cattle? What serovars are responsible?

Answer 18

Abortions without premonitory signs, stillbirths, weak calves, and low fertility syndrome
Hardjo-bovis, Pomona, Icterohaemorrhagiae

Question 19

What are the common signs of Leptospirosis in swine? What serovars are responsible?

Answer 19

Similar to bovine signs.

Pomona; sheds large # of this is a common source of infection for other humans and animals

Question 20

What are the common signs of Leptospirosis in horses? What serovars are responisble?

Answer 20

Abortions and anterior uveitis (moonblindness)

Pomona and others.

Question 21

What are the common signs of Leptospirosis in dogs? What serovars are responsible?

Answer 21

Acute hepatitis, with acute to chronic interstitial nephritis. Can also see meningitis and pulmonary vasculitis.
Canicola and pomona will cause the development of chronic renal disease.

Question 22

What causes the enhancement of Leptospirosis in Iowa?

Answer 22

Warm, wet conditions. Common in summers with a lot of rain or flooding.

Question 23

T/F Some veterinarians have decided to stop vaccinating against this, leading to an increase in cases

Answer 23

TRUE; have seen anaphylactic reactions to some of the bacterins that are used

Question 24

T/F Leptospirosis is an occupational hazard to veterinarians

Answer 24

TRUE; what the hell are we even doing?

Question 25

Severe Leptospirosis infection in humans is often associated with what clinical signs due to what serovar?

Answer 25

hepatic or renal failure

Icterohemorrhagiae

Question 26

T/F Human to human spread of Leptospirosis is frequently seen

Answer 26

FALSE; it is most commonly seen in rats to human and dogs to human spread

Question 27

What are some of the diagnostic tools that can be used to detect Leptospirosis infection?

Answer 27

Serological, which can detect antibody to Leptospires in serum: Microscopic agglutination test, PCR of urine, and ELISA
Culture: needed for definitive identification of infecting serovar, as it is the most accurate method
Can also use Darkfield microscopy of urine or silver staining

Question 28

T/F Immunization against Leptospira protects the host against clinical infection

Answer 28

FALSE; only protects against clinical disease

Question 29

What are some of the vaccines that are available for dogs?

Answer 29

Multivalent bacterins are available for many animals and dogs, cattle, and swine are most commonly vaccinated.
There are no vaccinations for horses or humans

Question 30

How do you treat Leptospirosis?

Answer 30

Ampicillin/Penicillin first to kill the organisms in systemic circulation followed by Tetracycline