Question

Which of the following groups of bacteria are commonly associated with causing mastitis?

• A. Bacillus cereus, Clostridium sp, and Campylobacter sp.
• B. Streptococcus aureus, Staphylococcusa agalactie, and Escherichia coli
• C. Mycobacterium bovis, Coxiella burnetii, and Borrelia sp.
• D. Salmonella Typhi, Shigella sp, and Vibrio cholerae.

Hint:

The "Big Three" pathogens responsible for mastitis in dairy herds are Staphylococcus aureus, Streptococcus agalactiae, and environmental E. coli.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Mastitis is an inflammatory condition of the mammary gland (udder) in dairy animals, typically caused by bacterial pathogens that enter through the teat canal.

Step 2: Detailed Explanation:
- Mastitis pathogens are broadly classified as contagious or environmental:
- Contagious pathogens live on the skin of the udder or inside the teat. Key examples include Staphylococcus aureus and Streptococcus agalactiae (spelled as "Staphylococcusa agalactie" in the question paper).
- Environmental pathogens live in the animal's surroundings (such as bedding, soil, and water). A key example is the coliform bacterium Escherichia coli.
- Option (B) contains these primary contagious and environmental mastitis-causing pathogens.
- The other options contain spore-formers, zoonotic pathogens, or enteric pathogens, which are not primary causes of mastitis.

Step 3: Final Answer
The group of bacteria most commonly associated with causing mastitis is Streptococcus aureus, Staphylococcusa agalactie, and Escherichia coli.