Spirochete Flashcards
Appear crokscrew motilaty in wet smear ?
Spirochetes
Fontana: (Silver stain): thickening of the wall, so can be
seen by ordinary light microscope: dark brown on
brownish yellow background
Treponema pallidum: organisim causing syphilis
Chancre is hard, painless, superficially ulcerated lesion.
• Chancre is covered by exudates, very rich in spirochetes (highly
infectious).
Syphilis
Chronic granulomata gummata.
Character of ?
Untreated tertiary syphilis , cell mediated immune response
Hutchinson triad of congenital syphilis
Hutchinson teeth , interstitial keratitis , deafness
Absolute diagnosis of syphilis caused by Treponema pallidum during the first and second
stages can be made by
Dark field microscopy: reveals tiny helically-shaped
organisms moving in a corkscrew-like fashion.
Congenital syphilis: diagnosed by detection of
anti-syphilitic IgM antibodies in the baby.
Regarding syphilis, which one of the following is most accurate?
(A) The characteristic lesion of primary syphilis is a painful vesicle on the genitals.
(B) In secondary syphilis, the number of organisms is low, so the chance of transmitting the disease to others is low.
(C)
In secondary syphilis, both the rapid plasma reagin (RPR) and the fluorescent treponemal antibody-absorbed (FTA-ABS)
tests are usually positive.
(D) The antibody titer in the FTA-ABS test typically declines when the patient has been treated adequately.
(E) In congenital syphilis, no antibody is formed against T. palli-dum because the fetus is tolerant to the organism.
In secondary syphilis, both the rapid plasma reagin (RPR) and the fluorescent treponemal antibody-absorbed (FTA-ABS)
tests are usually positive.
Benzathine penicillin G is used to treat primary and secondary syphilis rather than procaine penicillin G. Which one of the following is the best reason for this choice?
(A) Patients allergic to procaine penicillin G are not allergic to benzathine penicillin G.
(B) Benzathine penicillin G has a higher minimal inhibitory concentration than procaine penicillin G.
(C) Benzathine penicillin G penetrates the central nervous system to a greater degree than procaine penicillin G.
(D) Benzathine penicillin G is a depot preparation that provides a long-lasting, high level of drug that kills the slow-growing
T. pallidum.
Benzathine penicillin G is a depot preparation that provides a long-lasting, high level of drug that kills the slow-growing
T. pallidum.
A 25-year-old woman has a papular rash on her trunk, arms, and palms. She says the rash does not itch. Vaginal examination reveals two flat, moist, slightly raised lesions on the labia. Material from a labial lesion examined in a dark field microscope revealed spirochetes.
Secondary syphilis caused by I. pallidum. The rash on the palms coupled with the vaginal lesions (condylomata lata) is compatible with secondary syphilis. Serologic tests, such as the nonspecific test (VDRL) and the specific test (FTA-ABS), were positive
Each of the following statements concerning the VDRL test for syphilis is correct EXCEPT:
(A) The antigen is composed of inactivated Treponema pallidum.
(B) The test is usually positive in secondary syphilis.
(C) False-positive results are more frequent than with the fluorescent treponemal antibody-absorbed (FTA-ABS) test.
(D) The antibody titer declines with appropriate therapy.
The antigen is composed of inactivated Treponema pallidum.
A 30-year-old woman with systemic lupus erythematosus is found to have a positive serologic test for syphilis (VDRL test).
She denies having had sexual contact with a partner who had symptoms of a venereal disease. The next best step would be to:
(A) Reassure her that the test is a false-positive reaction related to her autoimmune disorder
(B) Trace her sexual contacts for serologic testing
(C) Treat her with penicillin
(D)Perform a fluorescent treponemal antibody-absorbed (FTA-ABS) test on a specimen of her serum
Perform a fluorescent treponemal antibody-absorbed (FTA-ABS) test on a specimen of her serum
Each of the following statements concerning the fluorescent treponemal antibody-absorbed (FTA-ABS) test for syphilis is correct EXCEPT:
(A) The test is specific for Treponema pallidum.
(B) The patient’s serum is absorbed with saprophytic treponemes.
(C) Once positive, the test remains so despite appropriate therapy.
(D) The test is rarely positive in primary syphilis.
The test is rarely positive in primary syphilis.
CASE 23. Your patient is a 60-year-old man with confusion for 2 months. He has no history of fever or stiff neck. On physical examination, he was ataxic and his coordination was abnormal. A diagnosis of tertiary syphilis was made by the laboratory.
621. Of the following tests, which one is the MOST appropriate to make a diagnosis of tertiary syphilis?
(A) Spinal fluid culture to grow the organism
(B) Stain for inclusion bodies in the lymphocytes in the spinal fluid
(C)Test for antibody in the spinal fluid that reacts with cardiolipin
(D) ELISA for the antigen in the spinal fluid
)Test for antibody in the spinal fluid that reacts with cardiolipin
A 75-year-old man with substernal chest pain was found to have angina pectoris caused by syphilitic aortitis that affected his coronary arteries. Of the following, which one is the MOST likely way that the diagnosis of syphilis was made?
(A) Blood culture
(B) Culture on Thayer-Martin medium (chocolate agar with antibiotics)
(C) Detecting antibodies to cardiolipin in his blood
(D) Detecting treponemal antigen in his blood
(E) Western blot assay
Detecting antibodies to cardiolipin in his blood
