This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
Bisected pearls appearance on culture medium is seen in ? 
Select and explain. 
A. Brucella, B. Bordetella, C. Haemophilus ducreyi, D. Pseudomonas
B: Bordetella
Answer: B: Bordetella 
Explanation: Ans. is 'b' i.e., Bordetella Bordetella are gram-negative, capsulated, fimbriated, nonmotile coccobacillus.They show bipolar metachromatic granules on staining with toluidine blue.