Immunosuppressive effect of Babesia bovis immunogens on immunization against foot and mouth disease

The impact of natural infection with Babesia bovis on the immune response to FMD vaccine in calves was studied. Three groups of calves, group [1] were Babesia bovis free and vaccinated with inactivated FMD vaccine, group [2] naturally Babesia bovis infected and vaccinated with inactivated FMD vaccine, while group [3] was kept as non infection non vaccinated control. The humoral immune response of each group was measured by serum neutralization test [SNT] for a period of 16 weeks. Babesia [B.] bovis naturally infected group of calves [gp. 2] showed tendency of lower antibody responses in comparison with uninfected [gp. 1] post vaccination with Foot and Mouth Disease [FMD] vaccine. Parasitaemia of B.bovis infected calves were ranged from 1.5% to 2.5% at time of vaccination accompanied with reduction in packed cell volumes [PCV] up to 23% less than control group. The parasite persisted in the blood of infected calves as carriers with low parasitaernia. Three isolates of B.bovis have been identified. Protein characterization of the three isolates of B.bovis immunogens resulting in immunosuppressive effect was investigated. The isolates identified and propagated in cell culture using microaerophilus stationary phase and characterized by sodium dedocyle sulphate polyacrylamide gel electrophoresis [SDS-PAGE] and Western immunoblot. The molecular weights of antigens were varied froml2 to 165 Kilo Daltons [KDa]. The isolates showed totally 30 polypeptide antigens. Nineteen antigens were detected as homologous and common between the isolates, their molecular weights were 160, 152, 132, 110, 85, 77, 70, 67, 60, 49, 45, 40, 39, 35, 33, 30, 23, 18 and 12 KDa. While the other 11 antigenic bands were detected as heterologous and differ between the isolates, their molecular weights were 165, 155, 153, 144, 140, 120, 115, 112, 62, 37 and 20 KDa. Isolates no. I, 2 and 3 contained 24, 28 and 24 out of the 30 immunogens respectively. The immune suppressive effect by reduction in serum neutralizing antibody titers of B.bovis infected calves might be due to one or more of B.bovis common antigens

Molecular detection of Babesia equi in infected and carrier horses by polymerase chain reaction

Twenty-three blood samples were used in this study; five were from five naturally infected horses with Babesia equi [B. equi], while eighteen were from asymptomatic horses with equine babesiasis from different localities in Egypt. All samples were subjected to microscopic examination, indirect fluorescent antibody test [IFA] and polymerase chain reaction [PCR]. The carrier animals were microscopically detected in 7 out of 18 samples [38.8%] and in 9 of 18 by using IFA [50%], whereas PCR revealed that 14 samples were positive [78%]. Two synthetic oligonucleotide primers, based on the B. equi merozoite antigen gene [EMA-1] were used. A 819 bps DMA fragment is specifically amplified from the gene encoding EMA-1 of B. equi. Our results demonstrate that PCR is a valuable technique for routine detection of B. equi in chronically infected horses, even at low parasitaemia levels