- Assalamu alaikom, welcome back to another ATP video!
- So today we will be talking about Proteus Mirabilis. It will be a short, concise video,
and hope you get the most out of it! To start with, Proteus belongs
to a big family of bacteria known as Enterobacteriaceae which are gram negative rods.
And there are actually many Proteus
species such as P. vulgaris and P. penneri, but today we will be focusing on Proteus Mirabilis.
So now let us talk about the features of Proteus Mirabilis.
So this organism is a facultative anaerobic bacillus which means it can
grow in both the presence or absence of oxygen.
It’s most commonly found in the human intestinal tract as part of normal flora,
and they specifically colonize the colon and the urethra especially in females.
And it’s specifically characterized by its vigorous motility and its ability to produce
urease enzyme, and we will be talking about the importance of that later in the video.
Proteus possess some virulence factors that enable the organism to cause the disease.
First of all, Proteus Mirabilis exhibits flagella that allows the organism to be freely motile.
Also, it possesses fimbriae that facilitate its attachment to the epithelium of the host tissue,
and in our case it’s the uroepithelial cells of the urinary tract.
Another striking feature about Proteus is that it produces the enzyme urease which hydrolyzes the
urea in urine into ammonia and CO2. This in turn, raises the pH and produces an alkaline urine.
We have mentioned before that Proteus spp. are part of the human intestinal flora,
so they can cause infection upon leaving this location. They may also be transmitted
through contaminated catheters (particularly urinary catheters) or by accidental parenteral
inoculation. However, the specific mode of transmission has not been identified
Proteus primarily cause urinary tract infections, both community- and hospital-acquired.
And as we’ve explained before that Proteus exhibit some virulence factors such as the flagella,
the fimbriae, and the ability to produce urease enzyme which turn
the urine environment into an alkaline one, and thus facilitating the survival of the organism.
This alkaline urine not only facilitates its survival, but it also encourages the formation
of stones called “struvite” which are composed of MAP: magnesium, ammonium, and phosphate.
And those struvite stones often manifest as staghorn calculi in the renal pelvis.
Proteus cause signs and symptoms of UTIs such as dysuria, urinary frequency, and flank pain. And as
you can see, those signs and symptoms caused by Proteus spp. cannot be distinguished from
other members of the Enterobacteriaceae, or from stone symptoms for that matter.
There are many biochemical tests and methods that can identify Proteus spp,
but we will be mentioning only some of them.
So to start with Proteus can be identified on different Culture plates.
One of those for example is blood agar,
as the organism produces expanding waves on the surface of the agar, and this effect is known
as “swarming” effect which is attributed to the vigorous motility of the organism.
In addition, Proteus can grow on MacConkey’s agar,
and it produces non–lactose-fermenting (colourless) colonies.
And it can grow on TSI agar as well,
as it produces a black color due to its ability to produce H2S.
Another thing about Proetus spp is that the urine sample that contains the organism
produce a very distinct fishy odor.
Most Proteus strains are sensitive to extended spectrum ampicillin,
trimethoprim-sulfamethoxazole, and cephalosporins. After we’ve discussed everything about Proteus
Mirabilis, now the question arises: how we can prevent the infection?
Unfortunately, there are no specific preventive measures,
and no vaccines are available at the present time.
However, many hospital-acquired UTIs can be prevented by prompt removal of urinary catheters.
To sum up: Today we have talked about Proteus Mirabilis.
We’ve said that it’s a gram-negative rod that’s part of the normal human GI flora.
It primarily causes UTIs. And it’s characterized by its ability to
produce a distinct fishy odor of the urine, and its ability to produce
an alkaline urine and struvite stones that can manifest as staghorn calculi.
It can be identified on blood agar by its swarming motility,
and it can be treated with ampicillin, trimethoprim-sulfamethoxazole, and cephalosporins.
And that’s it for Proteus Mirabilis, we hope you found it beneficial!
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