00:01
Now as far as the clinical features of gonorrhea go,
this organism is notorious for producing
very, very severe dysuria.
00:14
Urination is extremely painful.
00:18
It would be very unusual
if gonorrhea were totally asymptomatic.
00:23
It's possible but very unusual.
00:28
The urethral discharge may start out as scant and mucoid.
00:33
But within 1 to 2 days, it is frank pus.
00:37
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.
00:55
If patients don't seek treatment,
this syndrome will resolve in several weeks.
01:05
And this cartoon shows what these
organisms look like under the microscope.
01:12
You notice that they are inside of neutrophils.
01:16
And they are diplococci, pairs of cocci.
01:21
And the other thing to notice is that
the flat sides of these cocci are apposed.
01:27
They are not end to end like in
Streptococcus pneumoniae.
01:32
So biscuit-shaped diplococci,
notably inside of neutrophils.
01:42
Now to prove that a patient has
gonorrhea versus non-gonococcal urethritis,
you would want to culture the discharge
and Gram-stain the discharge.
01:57
The typical culture media is a media known as
Thayer-Martin medium.
02:06
Thayer-Martin is nothing more than chocolate agar,
which will grow many, many organisms,
and supplies hemin and nicotinamide adenine dinucleotide
to fastidious organisms.
02:19
So many things will grow on Thayer-Martin media,
but we're only interested in isolating Neisseria gonorrhoeae.
02:30
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.
02:39
For example, we put vancomycin
and you may know that vancomycin
is broad spectrum for Gram-positive organisms.
02:49
So therefore, no Gram-positives should grow on Thayer-Martin.
02:54
The other thing in Thayer-Martin is colistin.
02:58
Colistin is a broad spectrum, Gram-negative antibiotic.
03:03
In other words, for Gram-negative rods
like E. coli, like pseudomonas,
and other things that may tend to grow.
03:13
But those won't grow with colistin
added to thayer-martin media.
03:18
And finally, nystatin which is an antifungal agent
will keep the growth of yeast
and other fungi away.
03:29
And so therefore, Thayer-Martin media is a
highly selective media.
03:36
In general, you use Thayer-Martin only for Neisseria gonorrhoeae.
03:42
There are other things you would use chocolate agar for
but for Thayer-Martin, it's gonorrhea.
03:50
Now as far as the Gram-stained smears,
we've already discussed that they're Gram-negative
intracellular diplococci.
04:00
In contrast, this particular view with the cartoon shown.
04:05
But I think you can still see the these are flat sides
apposed Gram-negative diplococci.
04:13
And the Gram stain is very, very sensitive
in symptomatic men.
04:21
In other words, Gram-stain that discharge
and you should be able to find these organisms.
04:28
However, if the unusual scenario obtains
that the man is asymptomatic,
then the Gram stain is only 50% sensitive.
04:43
What is now being used in many laboratories,
instead of culture
is something called the
nucleic acid amplification test.
04:56
This has largely replaced cultures for screening,
especially in asymptomatic genital infections.
05:05
And the test is able to detect not only Neisseria gonorrhoeae,
but it's often combined to detect Chlamydia trachomatis.
05:19
However, it is not more sensitive than a regular culture.
05:26
It just depends upon the facilities that the laboratory has.
05:31
However, it is very, very sensitive for Chlamydia trachomatis
and culturing Chlamydia trachomatis
is cumbersome and not used widely.
05:45
But the bottomline is that all patients with urethritis
should be tested for both Neisseria gonorrhoeae and Chlamydia trachomatis.