Deck 25: Spirochetes

Question 1

Which of the following spirochetes is associated with renal failure?

A) Borrelia burgdorferi
B) B) recurrentis
C) Leptospira interrogans
D) Treponema pallidum ssp. pertenue

Answer 1

Leptospira interrogans

Question 2

A 27-year-old male discovers a tick attached to his waist three days after he returns from camping in the Rocky Mountains. He removes it and forgets about it until an area of redness appears at the same site as the tick bite. Because he develops a fever, he decides to visit his physician. His infection is most likely caused by

A) Borrelia burgdorferi.
B) B) recurrentis.
C) Leptospira interrogans.
D) Treponema pallidum ssp. pertenue.

Answer 2

Borrelia burgdorferi.

Question 3

Each of the following causes a nonvenereal skin disease except

A) Treponema pallidum ssp. pertenue.
B) T. pallidum ssp. endemicum.
C) T. pallidum ssp. pallidum.
D) T. carateum.

Answer 3

T. pallidum ssp. pallidum.

Question 4

Leptospira spp., Borrelia spp., and Treponema spp. share all of the following

A) motility.
B) possession of a sheath.
C) corkscrew shape.
D) ability to cause human disease.

Question 5

The spirochete Leptospira spp. differs morphologically from Borrelia and Treponema spp. by its

A) hooked ends.
B) sheath.
C) growth in liquid medium.
D) motility in a wet mount of peripheral blood.

Question 6

Which of the following cannot be cultured in-vitro?

A) Borrelia burgdorferi
B) B) recurrentis
C) Treponema carateum
D) Leptospira interrogans

Question 7

Which stage of syphilis demonstrates no clinical manifestations but is characterized by seroreactivity?

A) Primary
B) Secondary
C) Latent
D) Tertiary

Question 8

Nontreponemal tests can be used to diagnose all stages of syphilis except

A) primary.
B) secondary.
C) latent.
D) tertiary.

Question 9

The appearance of erythema migrans in individuals who have infection with Lyme disease occurs

A) immediately after removal of the tick.
B) during stage 1.
C) during stage 2.
D) during stage 3.

Question 10

Serologic testing is a viable option for the diagnosis of infection with Borrelia burgdorferi for all disease stages except

A) Stage 1.
B) Stage 2.
C) Stage 3.
D) when the individual exhibits CSF symptoms.

Question 11

A positive VDRL test

A) indicates immunity against Treponema pallidum ssp. pallidum.
B) indicates tertiary disease.
C) must be confirmed with a nontreponemal test.
D) must be confirmed with a treponemal test.

Question 12

An individual with Lyme disease can present with a false positive reaction with the _______ test.

A) TPHA
B) VDRL
C) RPR
D) darkfield microscopy

Question 13

A physician requests a darkfield examination for syphilis on an oral lesion of a 33-year-old male. The image provided demonstrates the results of the test.
Source: CDC and Schwartz
How should this darkfield examination be interpreted?

A) Positive for Treponema pallidum ssp. pallidum
B) Negative for T. pallidum ssp. pallidum
C) Unable to interpret
D) Positive for primary syphilis

Question 14

A 33-year-old female, at 10 weeks gestation, tests positive using a nontreponemal test but negative when tested using a treponemal test. What could account for the difference in results?

A) Previous therapy for syphilis
B) Pregnancy
C) Lyme disease
D) Reinfection after treatment

Question 15

A 10-year-old male from Africa presents with skin lesions as seen in the image provided.
Source: CDC and Dr. Peter Perine
The lesions demonstrate spirochetes on darkfield examination. The treponemal
Serologic tests are also positive. You suspect the infection is due to

A) Treponema pallidum ssp. pallidum.
B) T. pallidum ssp. endemicum.
C) T. carateum.
D) T. pallidum ssp. pertenue.

Question 16

A 20-year-old male from South America, presents with blue-gray colored skin lesions on his legs. His hands show areas that lack pigmentation. His blood tests positive for both nontreponemal and treponemal tests. A darkfield examination image of one of the lesions is provided.
Source: CDC
What disease do you suspect in this individual?

A) Endemic syphilis
B) Pinta
C) Yaws
D) Venereal syphilis

Question 17

Liquid Barbour-Stoenner-Kelly medium incubated at 30°C in the dark is used for culture of

A) Leptospira interrogans.
B) Borrelia spp.
C) Nonvenereal treponemes.
D) a and b.
E) b and c.

Question 18

Which of the following case histories best correlates with the presence of Leptospira interrogans in the urine?

A) A boy scout who played with field mice he caught while on a camping trip.
B) A hiker bitten by a tick on his last trip to the mountains.
C) A homeless female with poor personal hygiene.
D) A park ranger who presents with an erythema migrans on her leg.

Question 19

A 37-year-old veterinarian had to travel into the brush on her last farm visit to help deliver a calf. Once home, she discovered a tick attached to the back of her knee. She developed fever about two weeks after the incident. The fever broke after about four days but then returned. She visits her physician, and he orders blood cultures and a complete blood count where a hematologist notes the presence of spiral organisms on the fixed, stained blood smear.
In addition to observation of the organism, what other testing is recommended for determination of the causative agent?

A) No other testing is necessary
B) ELISA
C) Culture in BSK medium
D) Darkfield examination

Question 20

A physician asks you if the microbiology department has Fletcher's medium in stock.
What organism does she suspect based on this request?

A) Borrelia burgdorferi
B) B) recurrentis
C) Leptospira interrogans
D) Nonvenereal Treponema spp.