USMLE Forum Archives - USMLE Step 1 - Microbiology
Microbiology
mohhaider - 08-15-08 02:52
24-year-old man complains of a urethral discharge and painful urination. A gram-stain smear of the discharge shows many pus cells (neutrophils) but no bacteria. which is the one most likely to cause the discharge?
(A) Neisseria gonorrhoeae
(B) Staphylococcus aureus
(C) Streptococcus pyogenes
(D) Treponema pallidum
(E) Ureaplasma urealyticum
mohhaider - 08-15-08 02:52
24-year-old man complains of a urethral discharge and painful urination. A gram-stain smear of the discharge shows many pus cells (neutrophils) but no bacteria. which is the one most likely to cause the discharge?
(A) Neisseria gonorrhoeae
(B) Staphylococcus aureus
(C) Streptococcus pyogenes
(D) Treponema pallidum
(E) Ureaplasma urealyticum
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#2
Re: Microbiology sshahraz - 08-18-08 08:43 i would go with D as T Pallidum needs dark filed visualization
#3
Re: Microbiology
mohhaider - 08-18-08 14:40 The answer is E
Mycoplasma organisms are true bacteria that are extremely small and have no cell walls .U. urealytrcum causes a small percentage of the nongonococcal urethritis in men. If the urethral discharge was stained and examined for organisms, none would be visible in the light microscope due to the small size, although PMNs would be present, attempting to phagocytize the organisms.
Treponema pallidum need dark field microscope but does it cause urethral discharge ?(Never heard that symptom of syphlis .
#4
Re: Microbiology sshahraz - 08-18-08 22:55 Your answer is quite convincing and I would prefer E over D (my choice) , however to answer your concern about having urethral discharge following T. Pallidum infection, I would say that one of the differentials of urethral discharge is syphilis. My reference is MD Consult.
#5
Re: Microbiology babbu5508 - 07-31-10 23:36 U. urealyticum is part of the normal genital flora of both men and women. It is found in about 70% of sexually active humans.
It had also been described to be associated with a number of diseases in humans, including non-specific urethritis (NSU), infertility, chorioamnionitis, stillbirth, premature birth, and, in the perinatal period, pneumonia, bronchopulmonary dysplasia and meningitis.
#7
Re: Microbiology babbu5508 - 08-29-10 01:33 there are many causes of NGU.This is in part due to the large variety of organisms living in the urinary tract. Ureaplasma urealyticum and Mycoplasma genitalium are some of the culprits.
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