Question

A farmer has 5 cows with clinical chronic mastitis that have been cultured 3 times with "no growth" on blood agar each time. The cows do not appear systemically ill. He thinks culturing is a waste of time. What mastitis agent does the above history most represent?

Answer 1

Mastitis in cows represented by multiple negative cultures on blood agar and no systemic illness most likely indicates Mycoplasma as the causative agent, requiring specific culture conditions.

Step-by-step explanation:

The history of a farmer having 5 cows with clinical chronic mastitis with no growth on blood agar culture three times even though they appear not to be systemically ill most likely represents the mastitis agent Mycoplasma. This bacteria is notorious for chronic mastitis with no response to common antibiotics and negative culture results when using standard blood agar because Mycoplasma requires specific media and atmospheric conditions to grow. In cases of recurring or chronic mastitis where other common pathogens are not identified, special culturing techniques or alternate diagnostic methods may be required to identify Mycoplasma or other less common agents.