I am trying to create a lawn from a Nutrient Agar plate and when I follow all the steps, it doesn't work. It keeps telling me that it is contaminated and won't give me the option to select the antibiotic paper when I right click on the plate after transfer. It only gives me the option to replace caps/lids. Is it possible that there is some type of glitch in the program? Help please!
I was unable to recreate your problem. Here are the steps I followed:
1. I created a new unknown and chose Gram Positive Coccus for the subgroup. Making lawns for antibiotic testing is only available for Gram Positive bacteria.
2. After the Case Study and Gram stain, I chose nutrient agar plate from the media list.
3. I selected the swab as the inoculation tool. Swabs are only available for Gram positive bacteria because it is with them we create lawns for antibiotic testing.
4. I started the Bunsen burner.
5. I right-clicked to remove the cap/lid from tube and plate.
6. I dragged the inoculum tube to the burner to "flame it". A popup message told me it had been done.
7. I put the swab into the tube of inoculum, passing the tip of the swab through the mouth of the tube and down into the broth. A popup message told me I had stabbed the inoculum.
8. I swabbed the agar back and forth several times and the plate changed in appearance (took only a matter of seconds).
9. I right-clicked on the plate and selected the desired antibiotic disk from the list. It appeared on the plate.
10. I dragged the inoculum back through the flame again to flame the mouth of the inoculum tube. A popup told me I'd done it.
11. I right clicked on the plate and replaced the cap/lid. When I checked the two traffic signals at the top right, I found two green lights.
12. I turned off the burner and put the plate in the incubator.
If you follow these steps you should get the same result.
In VUMIE, lawns are only created when testing for antibiotic resistance. The only time that is called for (or allowed) in the software is when your unkown is a Gram positive coccus. So if you have a Gram negative rod as your unknown, you will be unable to create a lawn. We do this because the software loads tests based on the assigned microbe, allowing appropriate tests and not including tests not called for by the matrix. Therefore, be sure you have a Gram positive coccus assigned by the software before attempting an antibiotic sensitivity test.