Greetings from I & A lab! I know its been a long time since our last bulletin, but we've been hard at work brainstorming and developing new tests that can be very beneficial to your dairy. These tests along with this bulletin are about Mastitis caused by Mycoplasma, Staphylococcus, and Streptococcus organisms. I hope you find it interesting and informative.

Mycoplasma, Staphylococcus and Streptococcus - Do you know what Mycoplasma, Staphylococcus, and Streptococcus all have in common? ALL three of them are capable of causing mastitis in cattle! Can you tell me what makes them different from each other? Well, it's the treatment. Mastitis caused by Mycoplasma requires different treatment than mastitis caused by Staph or Strep. This is very important if you think that your herd might have a mastitis infection. It is important because improper treatment will have NO effect on the infection.

Mycoplasma - Now, let me tell you a little more about the smallest known organism able to survive extracellularly. Mycoplasmas are very small, pleomorphic (able to change shape) organisms that lack a cell wall. The absence of a cell wall is a very important and distinguishing characteristic of these organisms. Due to their lack of a cell wall, Mycoplasma species are resistant to penicillin. Now, most dairymen are familiar with penicillin. Penicillin is a common antibiotic used to treat bacterial infections such as mastitis caused by Staphylococcus or Streptococcus. It is effective against these and many other bacteria because of the thick cell wall of the bacteria. Penicillin interferes with the formation of the cell wall thereby destroying the bacteria. Now, remember I just told you that Mycoplasma have NO cell wall? Good, I'm glad you are right on track. So, if penicillin interferes with cell wall synthesis and Mycoplasma have no cell walls, what do you think will happen if penicillin is administered for a mastitis infection caused by Mycoplasma? If you guessed "nothing", you are correct. Nothing happens!! Absolutely nothing will happen because the penicillin has no effect on Mycoplasma!
This is why it is extremely important to distinguish a mastitis infection caused by Mycoplasma from an infection caused by Staph or Strep and guess what? That is where, we, Microbiologists and Lab Technicians come to rescue you. We have developed a series of tests to determine whether you have a mastitis infection caused by Mycoplasma or caused by Staph or Strep. We are very excited about our new accomplishments and wanted to share our news with you. If you suspect your herd to have a mastitis infection or if you have high somatic cells, I strongly urge you to have your milk tested.

Allow me to briefly explain our tests to you. First, we will plate a sample of raw milk onto Mycoplasma medium. Growth on this medium means your cattle have an infection caused by Mycoplasma. Results for this test may take up to 7 days due to the slow growth rate of the organism. Second, we will plate a sample onto Staphylococcus medium. Growth is usually observed in 24 hours. Therefore, results may be obtained in one day. Third, we plate a sample onto Streptococcus medium. Growth is also observed in 24 hours and results may be obtained within one day as well.

It is important to note that if the Streptococcus and the Staphylococcus test results are negative, this does not necessarily indicate that the Mycoplasma test will be positive. For example, older cattle have high somatic cell counts and they do not have mastitis.
If the results of the Staph and Strep test are positive, treatment with penicillin will be effective and the problem will be solved. However, if Mycoplasma is positive, penicillin will not be effective. It is important for you to consult with your veterinarian about proper treatment with other antibiotics.

If you have any questions about Mycoplasma or mastitis, please feel free to call and we will be happy to assist you as best we can!