<prompt> Which of these need both V and X factors?Hemophilus influenzaeH. ducreiH. paraphrophilusAll  <response>: Ans. is a i.e., Hemophilus influenzae Haemophilus The genus Haemophilus contain small, nonmotile, nonsporing, oxidase positive gram negative bacilli. They are characterized by their requirement of one or both of two accessory growth factors X and V present in blood. Thats why they are called haemophilus which means blood loving. Different species have different requirement :- H. influenzae, H. aegyptius, H. haemolyticus --0- Factor X V. H. Parainfluenzae, H. Parahemolyticus, H. Paraphrophilus --p. Factor V. H. ducreyi, H. aphrophilus ---0- Factor X. 