<prompt> Bisected pearls appearance on culture medium is seen in ?BrucellaBordetellaHaemophilus ducreyiPseudomonas  <response>: Ans. is b i.e., Bordetella Bordetella are gram-negative, capsulated, fimbriated, nonmotile coccobacillus.They show bipolar metachromatic granules on staining with toluidine blue. 