MSA Worksheet

Lab 11 – How does MSA select for bacteria and differentiate between bacteria

Submit to Lab 11 dropbox as Lab11-week8_LastName_FirstInital

Name____________________________ Date________________________

Section__________________________

Title:

Purpose:

Methods: Use of Mannitol salt agar to determine the virulence of potential pathogens

Lab manual page 241 -243

https://www.youtube.com/watch?v=ON4qQafGcfc

Results

If gram was completed what would you see on your microscope – What shape – What color? Color tells you if it is Gram + or Gram -

Skin swab –

Staphylococcus aureus, Staphylococcus epidermitidis, Escherichia coli

Gram stain results

Bacteria name	Gram stain result	Shape of bacteria

Three shapes cocci, rods (bacillus) spirochetes

The use of MSA allows the observer to see the presence of enyzmes that bacteria may produce to use a different carbohydrate.

Add a picture of the different reactions that are seen on the MSA

Cite your references! Needed to get points

Conclusion

What is the ingredient is selective in the MSAagar plates

What ingredient is the differential ingredient in these plates?

Describe the appearance of the MSA plates with the bacteria listed above.