A 25 years milkman comes to emergency department, saying that about 2 hours ago he began to feel feverish and weak; on examination he has a temperature of 40 degree centigrade, and a history of relapsing fever but no other pertinent findings. A blood cultures grows small gram positive rods that cause beta hemolysis on blood agar plate, incubated at room temperature. Which one of the following bacteria is most likely the cause?
Select one of the following: