Method of growing rickettsiae in Ixodes scapularis tick cell culture and preparing antigens and vaccines of rickettsiae

A tick cell culture comprising undifferentiated Ixodes scapularis cells infected with propagating rickettsiae, which propagating rickettsiae is infective for cattle.

A method for propagating A. marginale comprising:

• incubating A. marginale with tick cells derived from undifferentiated Ixodes scapularis in a culture medium supplemented with an organic buffer and a source of HCO.sub.3.sup.-, the culture medium suitable for growth of invertebrate cells to produce tick cells infected with A marginale, wherein said A. marginale propagates in the incubating cells, and wherein the propagated A. marginale is infective for cattle.

A method for propagating A. marginale comprising:

• incubating A. marginale with tick cells derived from embryonic Ixodes scapularis cells in a culture medium supplemented with an organic buffer and a source of HCO.sub.3.sup.-, the culture medium suitable for growth of invertebrate cells to produce tick cells infected with A. marginale;
• wherein said A. marginale propagates in the incubating cells, and wherein the propagated A. marginale is infective in cattle.

A tick cell culture comprising embryonic tick cells infected with propagating rickettsiae, which propagating rickettsiae is infective in cattle.

A tick cell culture comprising embryonic Ixodes scapularis tick cells infected with propagating rickettsiae, which propagating rickettsiae is infective in cattle.