Stalactite growth in a ghee broth culture is characteristic of

Yersinia pestis:The plague bacillus is a sho, plump, ovoid gram-negative bacillus.It is aerobic and facultatively anaerobicIt is not nutritionally exacting and grows on ordinary mediaIf grown in a flask of broth with oil or ghee floating on top, a characteristic growth occurs which hangs down into the broth from the surface, resembling stalactites .Ref: Ananthanarayan; 7th edition; Page no: 324