Undulant fever is caused by
Acute brucellosis is mostly due to B.melitensis. It is usually known as undulent fever, but this is misleading as only some cases show the undulent pattern. It is associated with prolonged bacteremia and irregular fever. Ref: Textbook of microbiology; Ananthanarayan and paniker's; 10th edition; Pg:347
Salmonella typhi
Staphylococcus aureus
Brucella melitensis
Coxiella burnetti
Bacteriology