Now as far as the clinical features of gonorrhea go,
this organism is notorious for producing
very, very severe dysuria.
Urination is extremely painful.
It would be very unusual
if gonorrhea were totally asymptomatic.
It's possible but very unusual.
The urethral discharge may start out as scant and mucoid.
But within 1 to 2 days, it is frank pus.
Interestingly enough, in contrast to urinary tract infections,
there's not the urgency to urinate,
and urinary frequency is not common,
like it is in a urinary tract infection.
If patients don't seek treatment,
this syndrome will resolve in several weeks.
And this cartoon shows what these
organisms look like under the microscope.
You notice that they are inside of neutrophils.
And they are diplococci, pairs of cocci.
And the other thing to notice is that
the flat sides of these cocci are apposed.
They are not end to end like in
So biscuit-shaped diplococci,
notably inside of neutrophils.
Now to prove that a patient has
gonorrhea versus non-gonococcal urethritis,
you would want to culture the discharge
and Gram-stain the discharge.
The typical culture media is a media known as
Thayer-Martin is nothing more than chocolate agar,
which will grow many, many organisms,
and supplies hemin and nicotinamide adenine dinucleotide
to fastidious organisms.
So many things will grow on Thayer-Martin media,
but we're only interested in isolating Neisseria gonorrhoeae.
So how do we get rid of the other organisms that might grow?
Well, what we would do is we put antibiotics
into the medium.
For example, we put vancomycin
and you may know that vancomycin
is broad spectrum for Gram-positive organisms.
So therefore, no Gram-positives should grow on Thayer-Martin.
The other thing in Thayer-Martin is colistin.
Colistin is a broad spectrum, Gram-negative antibiotic.
In other words, for Gram-negative rods
like E. coli, like pseudomonas,
and other things that may tend to grow.
But those won't grow with colistin
added to thayer-martin media.
And finally, nystatin which is an antifungal agent
will keep the growth of yeast
and other fungi away.
And so therefore, Thayer-Martin media is a
highly selective media.
In general, you use Thayer-Martin only for Neisseria gonorrhoeae.
There are other things you would use chocolate agar for
but for Thayer-Martin, it's gonorrhea.
Now as far as the Gram-stained smears,
we've already discussed that they're Gram-negative
In contrast, this particular view with the cartoon shown.
But I think you can still see the these are flat sides
apposed Gram-negative diplococci.
And the Gram stain is very, very sensitive
in symptomatic men.
In other words, Gram-stain that discharge
and you should be able to find these organisms.
However, if the unusual scenario obtains
that the man is asymptomatic,
then the Gram stain is only 50% sensitive.
What is now being used in many laboratories,
instead of culture
is something called the
nucleic acid amplification test.
This has largely replaced cultures for screening,
especially in asymptomatic genital infections.
And the test is able to detect not only Neisseria gonorrhoeae,
but it's often combined to detect Chlamydia trachomatis.
However, it is not more sensitive than a regular culture.
It just depends upon the facilities that the laboratory has.
However, it is very, very sensitive for Chlamydia trachomatis
and culturing Chlamydia trachomatis
is cumbersome and not used widely.
But the bottomline is that all patients with urethritis
should be tested for both Neisseria gonorrhoeae and Chlamydia trachomatis.