Babesiosis is a tick-borne disease of dogs caused by protozoan parasite Babesia canis. In the period 1997-2001 survey of incidence of babesia infection of pet dogs and faunistic study concerning ticks were undertaken in the Belgrade district. Four species of ticks were found in the investigated regions, namely: Ixodes ricinus, Rhipicephalus sanguineus, Dermacentor marginatus and Dermacentor reticulatus. The faunistic composition, relative abundance and population dynamics of detected species were investigated. Ticks were found on 32.39% (1278/3945) of examined dogs. Ticks Rhipicephalus sanguineus, Dermacentor reticulatus and Dermacentor marginatus are principal vectors of B. canis. Babesia canis was detected in R. sanguieneus (66.10%), D. reticulatus (46.40%) and D. marginatus.(18.70%). Babesiosis was detected in 74.07% (2922/3945) of examined animals with suspected clinical signs of infection.
A cDNA expression library prepared from Babesia gibsoni (B. gibsoni) merozoite mRNA was screened with a B. gibsoni-infected dog serum. A cDNA clone encoding 30 kDa protein was cloned and designated P30 gene. The complete nucleotide sequence of the P30 gene had 792 bp. Computer analysis suggested that the sequence of the P30 gene contained an open reading frame of 600 bp with a coding capacity of approximately 23 kDa. The native P30 protein of B. gibsoni with molecular mass of 30 kDa was identified by Westem blotting using anti-recombinant P30 mouse serum. The recombinant P30 protein expressed in Escherichia coli was used for antigen in an enzyme-linked immunosorbent assay (ELISA). The ELISA was able to detect the B. gibsoni infection and did not show any cross reactivity to B. canis-infected dog sera and normal dog sera. Furthermore, the antibody response against the recombinant P30 was maintained in dog experimentally infected with B. gibsoni even after the dog became the chronic stage of infection. These results demonstrated that the recombinant P30 might be a useful diagnostic reagent for detection of antibodies to B. gibsoni in dogs.
To investigate the morphology, immunophenotype and stimulatory activity of splenic dendritic cells (DC), a procedure was developed to obtain dendritic cell populations by mechanical tissue disruption of spleens followed by metrizamide density gradient centrifugation and cell sorting on the basis of CD11c expression. The resultant low density cell fraction consisted of a non-adherent cell population that could at least be characterized by typical DC morphology, constitutive levels of surface MHC class II and expression of DC specific markers.
The capacity for antigen presentation of the isolated CD11c+ DC was carried out using Toxoplasma gondii lysate antigen (TLA). The results describing the phenotype and accessory function provide some evidence that DC play a crucial role as antigen presenting cells (APC) with important implications for understanding the complex network regulating antigen uptake, processing and presentation.