Efficacy of purifiedanaplasma marginale initial bodies as a vaccine against anaplasmosis

Abstract

Anaplasma marginale initial bodies of the Florida strain were purified from infected erythrocytes using a combination of ultrasonic disruption, nonionic detergent and differential centrifugation. Immunochemical analysis revealed at least 12 A. marginale proteins in the molecular mass (m) range 81-15 kDa with a prominent band at 38 kDa. Several of these proteins remained insoluble in the presence of nonionic detergent. Preparations of purified Anaplasma initial bodies contained negligible erythrocytic contamination, as confirmed by the minimal induction of isoantibodies against bovine blood group antigens and the absence of delayed-type hypersensitivity to erythrocytic antigens in immunized animals. A total of 33 crossbred and purebred Holstein cattle were vaccinated with either 1.5, 1.0, or 0.1 mg protein of intact initial bodies, or with 1.0 mg of solubilized Anaplasma protein. The immunogens were supplemented with 3.0 mg Quil-A saponin adjuvant and administered in 2 subcutaneous injections given at a 4-week interval. A similar number of nonvaccinated cattle served as controls. Three months after vaccination, all cattle were challenged by inoculation of 10(9) virulent A. marginale of either the homologous (Florida) or heterologous (Venezuelan) strains. Vaccinated cattle showed solid protection after homologous and heterologous challenge, characterized by parasite clearance and minimal hematocrit reductions. Initial data from four field vaccine trials revealed a reduced incidence of clinical anaplasmosis among immunized animals. Use of immunogens consisting of purified A. marginale initial bodies offers a potential immunoprophylactic approach to control of bovine anaplasmosis.

Antigens and Alternatives for Control ofAnaplasma marginaleInfection in Cattle

“…Some killed vaccines were effective for the prevention of anaplasmosis (32,107), while others showed protection failures (3,62,91). It was demonstrated that some A. marginale isolates were not cross-protective, and it appears the vaccines are most effective when made from local isolates (91).…”

Characterization of an Immunogen of Anaplasma marginale

“…1). Montenegro et al 3 found an early response in animals vaccinated with purified initial bodies. This fact might be due to particular characteristics of the immunogen or to the management conditions of the animals.…”

“…1 Inactivated vaccine using purified Anaplasma initial bodies have been employed for the control of the disease and has improved upon previous vaccines owing to the elimination of the potential for inducing isoerythrolysis. 2,3 Characterization of A. marginale isolates from Cuba have shown differences at a molecular level. 4 The objective of the present work was to further characterize antigens from one of the isolates previously studied.…”

Homologous and Heterologous Immune Reactions between Venezuelan Geographic Isolates of Anaplasma marginale

“…1 Despite the economic losses, the use of profilactic methods have been based on foreign dead and live vaccines of A. marginale , and more recently on stabilates of A. centrale . 2 Studies have been made using native isolates 3 in the quest for a vaccine, but nothing deals with cross reactions between isolates. The goal of the work reported here was to analyze the presence of homologous and heterologous immune reactions between Venezuelan geographic isolates of Anaplasma marginale and to know if there is or is not antigenic reconnaissance, cross immune reactions, and protection between them.…”