Something cool

[yaah]

Can you name it?

Blood culture grew an organism, placed in a tube of semi-solid agar (a motility test). 2 days later, tube looks like this. What's the organism? Many people will probably know. It's just cool.

And yes, I know it's a bit blurry. It's supposed to be.

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[skoller]

Can you name it?

Blood culture grew an organism, placed in a tube of semi-solid agar (a motility test). 2 days later, tube looks like this. What's the organism? Many people will probably know. It's just cool.

And yes, I know it's a bit blurry. It's supposed to be.

Could it be Listeria?

I loved micro lab, but it was so very very long ago. That's the only motile microorganism I can recall.

 

[b&ierstiefel]

When I hear motility, I think flagella...am I on the right track? But lots of bacteria have flagella. Just by looking at the picture, I have no idea but if I were to venture a guess...Pseudomonas?

 

[yaah]

Could it be Listeria?

I loved micro lab, but it was so very very long ago. That's the only motile microorganism I can recall.

Sure is. Listeria is correct. That is known as the "umbrella" pattern. In textbooks it never actually looks that good - it sort of comes across in the picture.

This, BTW, was from a patient who was febrile, chills, etc, blood cultures grew "gram positive rods" and by the time they came back, the patient, who was only 25, was well enough so they discharged her home. In the d/c summary it was "blood cultures show gram positive rods, likely contaminant." No one in the path department ever suggested that these rods, which grew in both sets of cultures, were contaminants. They had to call her back in when it came back L. Monocytogenes.

Clinicians, sheesh. Order a test and ignore the result. Then don't order the test!

 

[grapewrath]

Thanks yaah. The pictures were awesome. So beautiful! I love micro.

 

[deschutes]

Cool pix! For your teaching collection perhaps?

I don't remember much microbio either, but my impression is that there are very few gram positive rods.

Was it a clinical clerk who did the discharge summary?

What antibiotic did they give her initially, I wonder.

 

[b&ierstiefel]

Sure is. Listeria is correct. That is known as the "umbrella" pattern.

That's cool as hell. Talk about buzzwords and actually seeing what the buzzword means in real life.

Just curious, what is the reason why the growth/migration occurs in an umbrella pattern?

 

[Fermata]

Just curious, what is the reason why the growth/migration occurs in an umbrella pattern?

I'm guessing that this is so because it's motility occurs in a "tumbling" pattern.

Let me try and find you a link.

 

[Fermata]

From: http://www.prep4usmle.com/community/topic9080.html

"I have seen the umbrella motility in a tube of SIM medium. It was a demo set up by our Ph.D. It was pretty cool. (SIM medium is for H2S, motility, and indole. It is semisolid, which allows the motility to be visualized along the stab line. With Listeria, you can see a little umbrella over the stab line).

Unfortunately, these organisms are now mostly ID'd via automated methods, so you don't get to see the cool reactions any more. I learned all my bugs on conventional media, which still comes in very helpful 29 years later. Young kids learn on the Microscan or Vitek, and the ID's are just a line of numbers."

 

[Fermata]

The "tumbling" motion is where one end goes over one other end.

(Okay....now I'm being verbose....buy hey...I love microbiology. )

 

[b&ierstiefel]

Cool cool...thanks for the info.

At first, I thought it couldn't be Listeria because I remembered learning a long time ago that Listeria motility is based on actin polymerization. But that mode applies to the intracellular phase of its lifecycle. I guess that other type of tumbling motility is important for its extracellular movement.

 

[yaah]

Listeria motility can also be demonstrated on a wet prep by seeing the end over end tumbling.

Why Listeria forms the umbrella pattern while others don't I am not sure. I have been trying to figure that out (well, not exhaustively), but so far unsuccessful.

I should take a picture of the red Serratia Marascens colonies we had. We also grew out pertussis in lab today.

In regards to clinical stuff - I don't know what Antibiotic she got. During the first hospital stay there weren't any because all the tests were initially negative and she was responding to treatment as though she had an IBD flare.

 

[b&ierstiefel]

In regards to clinical stuff - I don't know what Antibiotic she got. During the first hospital stay there weren't any because all the tests were initially negative and she was responding to treatment as though she had an IBD flare.

I was gonna look this up in the Sanford guide. However, after having no success trying to find it, I recalled I gave it away on my last day of sub-I's. Damn!

 

[Harbster]

I was gonna look this up in the Sanford guide. However, after having no success trying to find it, I recalled I gave it away on my last day of sub-I's. Damn!

Ampicillin would do the job!

 

[yaah]

We had a patient diagnosed with cryptosporidium based on an acid-fast stain of sputum, looking for AFB. Weird, eh? Crypto is an acid fast organism and has been known to show up on these tests, even though it is almost entirely a GI pathogen. Still trying to determine if the cryptosporidium is the cause of his apical lung cavitated lesion though.

This is what ours looked like: