Spirochetes

Question 1

What lab findings are useful to help diagnose Borrelia burgdorferi? (3)

Answer 1

loosely coiled motile spirochete visualized by dark field microscopy or Giesma stain, but cultures of human samples are rarely positive; IgM or IgG antibodies in serum; PCR available.

Question 2

What is the classic skin symptom of Lyme disease and how is it characterized?

Answer 2

erythema chronicum migricans. An expanding bulls eye red rash with central clearing.

Question 3

What are the manifestations in stage two Lyme disease? (2)

Answer 3

neurologic and cardiac manifestations

Question 4

What is the presentation of stage three Lyme disease? (1)

Answer 4

autoimmune migratory polyarthritis

Question 5

What are the clinical features of 2nd degree syphilis? (4)

Answer 5

fever, lymphadenopath, skin rashes, condylomata lata

Question 6

What symptoms are characteristic of end state syphilis? (4)

Answer 6

gummas, aortitis, neurosyphilis (tabes dorsalis), Argyll Robertson pupil

Question 7

What are the clinical stages of Borrelia burgdorferi? (3)

Answer 7

lyme disease. Primary-erythema migrans (bulls eye lesion)a, flu-like symptoms. Secondary-months later, cardiovascular (heart block) and neurological (Bell’s palsy) syptoms. Tertiary-arthritis of large joints, especially knee joint.

Question 8

What is the morphology of Leptospira interrogans?

Answer 8

spirochete

Question 9

What are the clinical manifestations of Leptospira interrogans? (2)

Answer 9

well’s disease leptospirosis)-7-13 day incubation followed by fever, chills and intense headache which resolve. Second part of illness resembles aseptic meningitis with serious vasculitis jaundice, uremia.

Question 10

How is Treponema pallidum transmitted? (2)

Answer 10

direct contact with lesion on mucous membranes. Also, mother to fetus (vertical) transmission.

Question 11

How does Treponema pallidum gram stain?

Answer 11

negative

Question 12

What is the morphology of Treponema pallidum?

Answer 12

spirochete (thin walled, flexible, motile spiral rods)

Question 13

microbiology Vignettes: Middle-age man has acute monoarticular joint pain and bilateral Bells palsy. What diease and how?

Answer 13

lyme, ixodes tick

Question 14

What are the symptoms of stage one Lyme disease? (2)

Answer 14

erythema chronicum migricans, flu-like symptoms

Question 15

Identify the major toxicity factor associated with Treponema pallidum.

Answer 15

antigens induce antibodies that react with cardiolipin

Question 16

Where in the US is Lyme disease common?

Answer 16

northeast (named after Lyme, Connecticut)

Question 17

How is Leptospira Interrogans transmitted?

Answer 17

swimming in or drinking water contaminated by animal urine (rats, dogs, cows).

Question 18

What lab findings are useful to help diagnose Treponema pallidum? (3)

Answer 18

cannot be grown on artificial media; Test is for anti-cardiollpin antibodies (RPL, VDRL tests); confirmation with other serological tests.

Question 19

What is the morphology of Borrelia burgdorferi?

Answer 19

spirochete

Question 20

What is the major reservoir for Borrelia burgdorferi?

Answer 20

white tailed deer

Question 21

How is Borrelia burgdorferi transmitted?

Answer 21

deer-tick bite

Question 22

What lab findings are useful to help diagnose Leptospira interrogans? (2)

Answer 22

tightly coiled spirochete only visible with dark field microscopy; only occasionally cultured from humans.

Question 23

What are the clinical manifestations of Treponema pallidum? (4)

Answer 23

congenital syyphilis-impaired vision, hearing and notched teeth. Primary syphilis-hard, non tender primary lesion appears after a few weeks and is highly infectious. Secondary-a few month after primary lesion has gone, maculopapulary rash on palms and soles or moist papules on body; condylomata lata; can spontaneously heal. Tertiary-1/3 will progress to granulomas anywhere skin, bones; gummas in brain, ascending aortic aneurisms.

Question 24

Treponemes are what type of organism?

Answer 24

spirochetes

Question 25

What doe VDRL detect? What disease is it used for?

Answer 25

nonspecific antibody that reacts with beef cardiolipin. Used for diagnosis of syphilis.

Question 26

How is Treponema visualized? Why?

Answer 26

dark-field microscopy, but only viewed after silver staining or with immunofluorescence. Very thin-walled structure.