A novel gene encoding 27-kDa protein was identified by the screening of Babesia gibsoni cDNA library
with acutely infected dog serum. The BgP27 is a single copy gene with a predicted open reading frame of
762 bp and 254 amino acids. The phylogenic analysis of the deduced amino acid of BgP27 demonstrated
considerable identities with members of Plasmodium berghei circumsporozoite protein family that ranged
between 18.4% and 22.8%. The BgP27 was expressed as a glutathione S-transferase fusion protein in Escherichia coli. The serum raised in mice against the recombinant protein specifically reacted with a
27-kDa protein in the extracts of B. gibsoni parasites. Confocal laser scanning microscopic observation
showed high fluorescent reactivity with both extracellular and intracellular merozoite. Furthermore, recombinant BgP27 was used as an antigen in an enzyme-linked immunosorbent assay (ELISA). Thus, the kinetics of the anti-BgP27 antibody was detected in serial serum samples collected from a B. gibsoni-infected dog. IgG levels were high throughout the course of infection. In addition, the ELISA was able to differentiate between B. gibsoni-infected dog serum and B. canis subspecies-infected dog serum or normal dog serum. The diagnostic performance of BgP27-ELISA revealed the potential use of the antigen for detection of infection in dogs.
This cross-sectional study was conducted to establish and compare the antibody titres and sero-prevalences of tick-borne infections among randomly selected Nkedi Zebu and Ankole cattle in the six villages of Akumoi, Aswii, Kamod, Osamito, Okokoma and Opungure in Soroti district, Uganda. The antibody titres were established using the indirect antibody detection ELISA tests.
The Nkedi Zebu had a significantly higher mean antibody titre against T. parva infection (1.8 ± 0.1)
compared to the Ankole cattle (1.2 ± 0.1). While the mean antibodies titres of Ankole against B. bigemina and A. marginale infections (2.2 ± 0.04, 0.05 ± 0.05) respectively were very similar to those of the Nkedi Zebu cattle (2.1 ± 0.05, 0.06 ± 0.05) respectively. Sero-prevalences of East Coast Fever, babesiosis and anaplasmosis (100%, 100%, 58%) among the Ankole cattle were quite similar to those of Nkedi Zebu cattle(99%, 100%, 57%) respectively.
This study has demonstrated that the Nkedi Zebu are better primed to produce antibodies against T. parva
as compared to the Ankole cattle, thus extra control strategies for tick-borne infections need to be instituted
if the Ankole cattle are to be reared successfully in this agro-pastoral farming system.
The in vitro inhibitory effect of fosmidomycin was evaluated against the asexual growth of bovine Babesia parasites (Babesia bovis and Babesia bigemina). In the cultures with these parasites, severe reduction of parasite growth was observed by the addition of 1.25 μg/ml of the final drug concentration. Under these conditions, B. bigemina was completely cleared until the third day of cultivation. On the other hand, B. bovis was completely eliminated on the fourth day when the concentration was 6.25 μg/ml in the culture. These parasites failed to grow again when a drug-free medium was substituted for the subsequent cultivation. The IC50 values of fosmidomycin against B. bovis were determined as 0.88 and 0.63 μg/ml in the in vitro cultures with serum-containing M199 and serum-free GIT media, respectively, while it was 0.55 μg/ml against B. bigemina in a serum-containing M199 medium. Severe morphological changes, such as pycnotic and degenerative changes, were preferably observed in the treated parasites. These results suggest that fosmidomycin can be a potent chemotherapeutic agent against bovine babesiosis.
Toxoplasma gondii microneme protein 2 (TgMIC2), an apically stored adhesin, was shown to be a key
participant involved in the initial attachment and invasion to a host cell. In this study, we had established the
clonal line of T. gondii tachyzoites which over-expressed TgMIC2 using the tetracycline repressor
(TetR)-based inducible gene expression system. The TgMIC2 over-expression significantly reduced
tachyzoite propagation in vitro (p < 0.002) and significantly reduced the parasite virulence in mice (p = 0.002). The over-expression of exogenous TgMIC2 caused the increase of mRNA expression level of
endogenous TgMIC2. Wild type parasites mainly expressed TgMIC2115 protein, the microneme store and the surface form of TgMIC2. Over-expression of TgMIC2 induced production of TgMIC2110, the cell surface form of TgMIC2 produced by N-terminal proteolytic processing of TgMIC2115. Some of tachyzoites became spherical shape having disordered apical complex after TgMIC2 over-expression. TgMIC2 over-expression did not effect mRNA expression level of TgMIC2-associated protein (TgM2AP), but appeared to cause the aberrance of TgM2AP protein. In conclusion, our results reveal the novel findings on the importance of the
regulation of TgMIC2 transgene expression on post-translational modification of TgMIC2 and TgM2AP, and
parasite’s morphology and propagation, with all together impacting the outcome of infection.
A total of 450 blood samples randomly collected from 218 (48.4%) cattle 66 (14.7%) sheep, 112 (24.9%) Goats,
4 (0.9%) donkeys and 50(11.1%) pigs from randomly selected herds from 8 villages in 4 districts (Bule – Kaltin,
Tungo, Kaltungo-East and Kaltungo-West) of Kaltungo LGA were examined for haemoparasites. These total
number of 450 animals comprises 115 (25.6%) males and 335 (74.4%) females. From the males, 76 (66.1%) are
cattle, 10 (8.7%) goats, 0 (0.0%) donkeys and 10 (8.7%) boar. While female consist of cattle 142 (42.4%), sheep
56 (16.7%), goats 93 (27.8%) donkeys 4 (1.2%) and sow 40 (11.9%). The blood samples from these animals
were analysed using a combination of thick and thin film technique and concentration methods; haematocrit
centrifuge technique (HCT). 22 blood samples screened were found to be positive for haemoparasites: 3 (13.6%)
were infected with Trypanosoma vivax, 1 (4.5%) T. theileri, 11 (50.0%) microfilariae, 4 (18.2%) Babesia spp and 3 (13.6%) Anaplasma marginale. T. congolense and T. brucei were not isolated. The average packed cell volume (PCV%) for infected and non-infected males were 26.2 ± 1.3 and 28.2 ± 0.5, while that of females was 24.1 ± 2.0 and 27.1 ± 2.1 respectively. Microfilariae is high in prevalence while T. vivax is low 3 (13.6%). However no single Glossina (Tsetse fly) was caught while few tabanids, stomoxys, chrysops and simulium were trapped. The findings reveals the area to be tsetse free and transmission of trypanosomiasis is mechanical due to presence of only stomoxys, tabanids and chrysops. Ticks were also picked from some of the herds.