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.
- 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!
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 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!