Piroplasms Research Articles

A promising new ELISA diagnostic test for cattle babesiosis based on Babesia bigemina Apical Membrane Antigen-1.

Babesiosis due to Babesia bigemina is a relevant tick-borne disease, affecting cattle worldwide. Many surface proteins of the pathogen including the Apical Membrane Antigen 1 (AMA-1) - have been analysed for vaccine and diagnostic purposes. This study focused on B. bigemina AMA-1 and on its use for the assessment of diagnostic tests. After bioinformatic analyses, AMA-1 codifying region was amplified and cloned into an expression vector used to induce protein synthesis in Escherichia coli cells. AMA-1 was purified by affinity chromatography and used to set up the best condition for an ELISA protocol. Bovine field sera positive to B. bigemina were used to evaluate the presence of anti-AMA-1 antibodies. In order to verify the assay specificity, sera positive to Babesia bovis or to the piroplasm Theileria annulata were also included. Significant differences were obtained between sera negative to both B. bigemina and B. bovis and samples positive to B. bigemina, to B. bovis or to both pathogens. No significant reaction was observed with T. annulata positive sera. The results showed that AMA-1 protein is suitable to be used as antigen in diagnostic assays for babesiosis diagnosis in cattle, as it does not show any cross reaction with anti-T. annulata antibodies.

Human exposure to piroplasms in Central and Northern Italy.

TA serosurvey has been conducted in Northern and Central Italy to investigate the presence in humans of antibodies against zoonotic Babesia and Theileria species. The study focused on a total of 432 volunteers, of which 290 were persistently exposed to tick bites because of their jobs (forester employees, livestock keepers, veterinary practitioners, farmers and hunters) and 142 resident in the same area less frequently exposed. An indirect fluorescent antibody test (IFAT) for humans was used to detect antibodies to Babesia microti, IFAT tests for veterinary use were modified to detect reactivity to Babesia bovis, Babesia canis and Theileria equi. A laboratory-derived ELISA was employed to detect antibodies to Babesia divergens. Both reactive and 10 negative sera were analysed against plasmodial antigens to evaluate possible aspecificity. A high reactivity to piroplasm antigens was found, showing significant difference between the sera of the two groups of volunteers (24% vs 7.%; p<0.001). No cross-reactivity was observed, while each professional group showed reactivity that would fit with the professional risk exposure. In particular, a high reactivity to B. microti and B. divergens antigens was observed in foresters and hunters (32% and 12%, respectively). This is the first report on the human seroreactivity to piroplasms in Italy; it also provides additional epidemiological information on these tick-borne zoonoses in Europe. Our findings suggest the possible occurrence of piroplasm infections in Italy and alert physicians to consider these otherwise neglected parasitic diseases when dealing with any febrile illness, especially in subjects exposed to tick bites.

Comparison of reverse line blot and -tubulin targeted nested polymerase chain reaction (PCR) techniques in the detection of Theileria and Babesia piroplasms in cattle in Uganda

Three hundred (300) blood samples from apparently healthy cattle were collected in areas around Lake Mburo National Park in Western Uganda. These were used in the comparison of the sensitivity and specificity of reverse line blot (RLB) and β-tubulin targeted nested polymerase chain reaction (PCR) in the detection of tick-borne piroplasms in cattle. The sensitivity of RLB technique for the detection of Theileria andBabesia species was 71.25% (95% CI: 60.05 to 80.82%) and the specificity was 57.50% (95% CI: 40.89 to 72.960%) while the sensitivity of the beta-tubulin targeted nested PCR was 62.5% (95% CI: 50.96 to 73.08%) and the specificity was 72.5% (95% CI: 56.11 to 85.40%). The positive predictive value using RLB was 77.03% (95% CI: 65.79 to 86.01%) and the negative predictive value was 50% (95% CI: 34.90 to 65.10%) while the positive predictive value using β-tubulin targeted nested PCR was 81.97 % (95% CI: 70.02 to 90.64%) and the negative predictive value was 49.15% (95% CI: 35.89 to 62.50%). The Kappa statistic for level of agreement in detection of tick-borne piroplasms between RLB assay and β-tubulin targeted nested PCR was 0.7984 which indicated substantial agreement between the two tests. The RLB assay allowed the detection of individual species that simultaneously infected the cattle. However, it was not possible to identify the species with the β-tubulin targeted nested PCR. Key words: Babesia, Theileria, β-tubulin, reverse line blot, sensitivity, specificity.

Canine Babesiosis: Epidemiological and Clinical Features

Babesiosis is a cosmopolitan disease produced by blood parasites Babesia, a genus of protozoal piroplasms and transmitted by ticks bites. In Europe canine babesiosis is produced by two species of protoazoals, Babesia canis and Babesia gibsoni that are very different by phenotype and genotype. Clinical signs vary depending on the species or subspecies that are involved. This study presents epidemiological and clinical aspects of the disease from the south part of the country. The study had been performed from January to December 2008 in the Clinics of The Faculty of Veterinary Medicine Bucharest, on a number of 508 suspected dogs. Suspicion was based on the clinical signs. Ticks had been discovered on the skin of the animals during examination proceeded by the doctors in the clinics or by the owners. Blood samples had been microscopically examined after MGG coloration, with an immersion objective. In parallel the identification of the ticks had been performed.

The piroplasm Theileria ovis detected in sheep in South Wales.

The piroplasm Theileria ovis detected in sheep in South Wales.

Taxonomy of the Piroplasms

Taxonomy of the Piroplasms

Division forms of two piroplasms in rodents

Division forms of two piroplasms in rodents

New piroplasms of a genet cat and a ground-squirrel from Kenya.

New piroplasms of a genet cat and a ground-squirrel from Kenya.

Dr Theiler on the Piroplasma Bigeminum of the Immune Ox

Dr Theiler on the Piroplasma Bigeminum of the Immune Ox