Microbiology: Nitrate Reduction Test

This video describes why the nitrate reduction test is performed, how the test works (principle), and what the results mean (result interpretation). The nitrate reduction test was performed on Neisseria meningitidis (GNDC), Moraxella catarrhalis (GNDC), and a negative control.

[@rosagonzalez6682]

I don't really leave comments on videos, but this video and the whole explanation was amazing!!! Thank you!

[@MedicalLabLadyGill]

Thank you so much for your support!!!! I am glad to hear it helped ♡

[@moona2771]

Super cool thank you

[@kevjumbaz]

omg missed your videos lady gill! glad to see that you're back :) wish I was your student haha

[@MedicalLabLadyGill]

Your comments always make me smile! Thank you so much for the support! It's been a really busy academic year and I have kind of been side tracked ; ) We have a new hematology analyzer! I look forward to doing more videos to beef up the hematology section, talk about the healthcare team, and cover more theory. I also want to video on site at some of our clinical partners to show the methodologies used. Hopefully, I can start focusing on these items soon! I have also been waiting for a great urine specimen but our local population doesn't seem to have much kidney trouble! Good for the patients but bad for student learning! LOL!

[@kevjumbaz]

@@MedicalLabLadyGill oh wow! hopefully there's still sufficient rest times for such busy academic years.. stress levels has been at an all time high recently. a new haematology analyzer indicates that we will be getting to see some rare cases of blood related diseases i hope! a good urine sample is definitely hard to come by especially ones that allow you to clearly identify microorganisms during microscopic urinalysis. the best i've come across are still only positive controls samples! :(

[@MedicalLabLadyGill]

@@kevjumbaz We'll see ; ) We do have lots of patients with SCD, anemia, and leukemia. Although I already have slides for said diseases, I would love to video a fresh specimen all the way through the process (CBC & Smear Review).

[@iamtseringgrg]

is B.alvei nitrate reduction positive or negative ?

[@malikbenslimane2873]

Hello i have a question, you dipped the inoculation loop in the broth and kept shaking it, our teacher told us that we shouldn't touch the broth but instead put the inoculum on the wall of the tube then shake the tube, and when i did like you here she told that it's completly wrong and that i have to redo it, why is that ?, is it optional or there are different cases for the two techniques ?

[@MedicalLabLadyGill]

The only reason I can come up with off the top of my head is because you may introduce atmospheric oxygen into the tube. We use a nitrate disc to test nitrate reduction capability of our anaerobes. Can you ask your professor for her reason?

[@malikbenslimane2873]

Hello, thanks for your reply, i asked and the prof told me that because there is a chance that the bacteria will stick to the pipette (we use sealed glass pasteur pipettes) specialy if you picked it from a solid and not a dilute solution she said it's better to put it on the dry wall of the tube then shake it, it made sense

[@emmawenzel2972]

if the organism was super positive, meaning when you added zinc and it stayed clear, does that mean it produces more atp than just a positve organism?

[@MedicalLabLadyGill]

That is a good question. I am not sure your can surmise that from the test. Remember, this test is done after an incubation period. There is no mechanism during that time to determine rate of gas production. The test is more qualitative.

[@aza4444]

Hi, I don't really know what medium is in the tube outside of nitrate, is it just a buffer solution?

[@MedicalLabLadyGill]

There are a couple of websites you can view for the information. The BD package insert comes up as a pdf in Google. Here is the link to the Hardy Diagnostics version catalog.hardydiagnostics.com/cp_prod/Content/hugo/NitrateBrothDT.htm

[@aza4444]

@@MedicalLabLadyGill I see, it's a broth specifically designed for this, no gel. Thank you for the response!

[@MedicalLabLadyGill]

@@aza4444 you're welcome!