Which of these need both V and X factors?

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. That's 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.