Trina Perrone

Serological prevalence of Babesia caballi and Theileria equi in horses of Lara State, Venezuela.

The main objective of this study was to demonstrate the occurrence of equine piroplasmosis (EP) in horses of Lara State, Venezuela, and to correlate it with the factors hosts sex and age in order to know the epidemiology of this disease at the Venezuelan Centroccidental Region. Antibody levels to Babesia caballi and Theileria equi were assessed in 360 equine serum samples, collected from 9 municipalities of Lara State, using an ELISA technique with recombinant antigens and monoclonal antibodies (Mabs). Antibodies to B. caballi were found in 254 horses (70.6%), whereas 181 animals (50.3%) were detected as seropositives to T. equi. In addition, 128 samples (35.56%) were seropositives to both hemoparasites. There were no significant differences between the seropositivity to B. caballi and T. equi with the factors sex and age of the horses. These results show that Lara State is an enzootic area for equine piroplasmosis, and are a contribution to a partial knowledge of the dynamic of this disease in Venezuela.

Secretome of Animal Trypanosomes

Animal trypanosomosis is one of the most severe constraints to agricultural development in sub‐Saharan Africa and is also an important disease of livestock in Latin America and Asia. The causative agents are various species of protozoan parasites belonging to the genus Trypanosoma, among which T. congolense and T. evansi are the major pathogenic species. The extracellular position of trypanosomes obliges us to consider both the parasite and its excreted/secreted factors in the course of the physiopathologic process. The advent of proteomics led us to propose a comparative approach of the proteome (i.e., the whole parasite content) and the secretome (i.e., naturally excreted/secreted molecules) of T. congolense and T. evansi with particular attention to common and specific molecules between strains of differing virulence and pathogenicity. The molecular identification of differentially expressed trypanosome molecules correlated with either the virulence process or the pathogenicity will provide new potential molecular targets for improved field diagnosis and chemotherapy of animal trypanosomosis.

Detection of Theileria equi and Babesia caballi infections in Venezuelan horses using Competitive-Inhibition ELISA and PCR.

The focus of this study was the detection of equine piroplasmosis in Distrito Capital, Miranda, Aragua, Guárico and Apure States from Venezuela, using two methods: Competitive-Inhibition ELISA and multiplex PCR and the analysis of the possible differences in occurrence in relation to the primary purpose of the horses, which is related to varied degrees of exposure to tick. Antibody levels to Babesia caballi and Theileria equi were assessed in 694 equine serum samples using Competitive-Inhibition ELISA, while PCR assays were performed in 136 horses, using two sets of oligonucleotides to establish the presence of T. equi, B. caballi or both. The overall seroprevalence of equine piroplasmosis was 50.2%, antibodies to B. caballi were found in 161 horses (23.2%), whereas 97 (14.0%) were seropositive to T. equi and 90 (13.0%) were positives to both parasites (mixed infections). PCR determinations (n=136) showed a prevalence of 66.2%, distributed in 84 (61.8% positives) for T. equi and, 6 (4.4%) were positive to both parasites. The cELISA showed higher levels of prevalence of B. caballi and mixed infections, as compared to the PCR method. This discrepancy can be explained by the different parameters that are evaluated by each technique, PCR detect the parasite itself, while cELISA detects antibodies to the parasite. By PCR, the highest prevalence was found in Apure state, where 92.3% of the samples were positive to T. equi infections. In this locality, free grazing animals are used for livestock management. This high prevalence may be linked to the tick species present in that area. More epidemiological studies will be necessary to assess the epidemiological status of equine piroplasmosis in Venezuela.

Variant surface glycoproteins from Venezuelan trypanosome isolates are recognized by sera from animals infected with either Trypanosoma evansi or Trypanosoma vivax

Highlights • Soluble forms of VSGs from seven Venezuelan animal trypanosomes were purified and characterized.• All purified soluble VSGs exhibited cross-reactivity with Trypanosoma vivax.• Anti-VSG antibodies behaved as markers of infection for non-tsetse transmitted trypanosomes.• All purified soluble VSGs can be used as diagnostic reagents for bovine trypanosomosis.

Na-pump activity in rat kidney cortex cells and its relationship with the cell volume

The present work was undertaken to evaluate whether changes in cell water content of rat kidney cortex cells can modulate the transport activity of the ouabain‐insensitive Na pump as they modulate the ouabain‐insensitive Na+‐ATPase. It was found that there is a close relationship between the cell volume and activity of the Na pump, whereas Na,K‐pump activity is not affected by variations in cell volume. When the cell water content is low, Na‐pump activity (Na+ transport and Na+‐ATPase activity) is minimal. Increases in cell water content produce a concomitant increase in Na‐pump activity.