From October 2010 to May 2011, blood samples were collected from 229 healthy horses from six different regions of the Central Province of Saudi Arabia. Sera were tested for Neospora spp. antibodies ...by a competitive inhibition enzyme-linked immunosorbent assay and confirmed by an indirect fluorescent antibody test. 23 horses out of 229 (10%) reacted positively to Neospora antibodies In competitive-inhibition enzyme-linked immunosorbent assay; five of them had greater than or equal to 50% inhibition. Samples were confirmed with indirect fluorescence test (IFAT) test and only two samples were positive with final titers of 50 and 100, while other samples were negative. This study Is the first investigation to determine Neospora spp. in horses from semi arid areas in Saudi Arabia which indicates that horses in Saudi Arabia are exposed to this parasite.
Neospora caninum is a protozoan parasite of animals. Until 1988, it was misdiagnosed as Toxoplasma gondii. Since its first recognition in 1984 in dogs and the description of a new genus and species ...Neospora caninum in 1988, neosporosis has emerged as a serious disease of cattle and dogs worldwide. Abortions and neonatal mortality are a major problem in livestock operations and neosporosis is a major cause of abortion in cattle. This review is focused on current status of neosporosis in animals based on papers published in the last five years. Worldwide seroprevalences are tabulated. Strategies for control and prevention are discussed.
We present the effects of two novel bumped kinase inhibitors, BKI-1517 and BKI-1553, against
tachyzoites
and in experimentally infected pregnant mice. These compounds inhibited tachyzoite ...proliferation of a transgenic beta-galactosidase reporter strain cultured in human foreskin fibroblasts with 50% inhibitory concentrations (IC
s) of 0.05 ± 0.03 and 0.18 ± 0.03 μM, respectively. As assessed by an alamarBlue assay, fibroblast IC
s were above 20 μM; however, morphological changes occurred in cultures treated with >5 μM BKI-1517 after prolonged exposure (>6 days). Treatment of intracellular tachyzoites with 5 μM BKI-1553 for 6 days inhibited endodyogeny by interfering with the separation of newly formed zoites from a larger multinucleated parasite mass. In contrast, parasites treated with 5 μM BKI-1517 did not form large complexes and showed much more evidence of cell death. However, after a treatment duration of 10 days
, both compounds failed to completely prevent the regrowth of parasites from culture. BALB/c mice experimentally infected with
Spain7 (Nc-Spain7) and then treated during 6 days with BKI-1517 or BKI-1553 at different dosages showed a significant reduction of the cerebral parasite load. However, fertility was impaired by BKI-1517 when applied at 50 mg/kg of body weight/day. At 20 mg/kg/day, BKI-1517 significantly inhibited the vertical transmission of
to pups and increased the rate of survival of offspring. BKI-1553 was less detrimental to fertility and also provided significant but clearly less pronounced protection of dams and offspring. These results demonstrate that, when judiciously applied, this compound class protects offspring from vertical transmission and disease.
Neospora caninum
causes neosporosis, a leading cause of bovine abortion worldwide. Uruguay is a developing economy in South America that produces milk to feed seven times its population annually. ...Naturally, dairy production is paramount to the country’s economy, and bovine reproductive failure impacts it profoundly. Recent studies demonstrated that the vast majority of infectious abortions in dairy cows are caused by
N. caninum
. To delve into the local situation and contextualize it within the international standing, we set out to characterize the Uruguayan
N. caninum
strains. For this, we isolated four distinct strains and determined by microsatellite typing that these represent three unique genetic lineages, distinct from those reported previously in the region or elsewhere. An unbiased analysis of the current worldwide genetic diversity of
N. caninum
strains known, whereby six
typing clusters
can be resolved, revealed that three of the four Uruguayan strains group closely with regional strains from Argentina and Brazil. The remaining strain groups in an unrelated genetic cluster, suggesting multiple origins of the local strains. Microsatellite typing of
N. caninum
DNA from fetuses opportunistically collected from local dairy farms correlated more often with one of the isolates. Overall, our results contribute to further understanding of genetic diversity among strains of
N. caninum
both regionally and worldwide.
Neospora caninum causes heavy losses related to abortions in bovine cattle. This parasite developed a complex defense redox system, composed of enzymes as glutathione reductase (GR). Methylene blue ...(MB) impairs the activity of recombinant form of Plasmodium GR and inhibits the parasite proliferation in vivo and in vitro. Likewise, MB and its derivatives inhibits Neospora caninum proliferation, however, whether the MB mechanism of action is correlated to GR function remains unclear. Therefore, here, N. caninum GR (NcGR) was characterized and its potential inhibitors were determined. NcGR was found in the tachyzoite cytosol and has a similar structure and sequence compared to its homologs. We verified the in vitro activity of rNcGR (875 nM) following NADPH absorbance at 340 nM (100 mM KH2PO4, pH 7.5, 1 mM EDTA, ionic strength: 600 mM, 25 °C). rNcGR exhibited a Michaelian behavior (Km(GSSG):0.10 ± 0.02 mM; kcat(GSSG):0.076 ± 0.003 s-1; Km(NADPH):0.006 ± 0.001 mM; kcat(NADPH): 0.080 ± 0.003 s-1). The IC50 of MB,1,9-dimethyl methylene blue, new methylene blue, and toluidine blue O on rNcGR activity were 2.1 ± 0.2 μM, 11 ± 2 μM, 0.7 ± 0.1 μM, and 0.9 ± 0.2 μM, respectively. Our results suggest the importance of NcGR in N. caninum biology and antioxidant mechanisms. Moreover, data presented here strongly suggest that NcGR is an important target of phenothiazinium dyes in N. caninum proliferation inhibition.
•CRISPR/Cas9-directed genome editing system was designed for editing the N. caninum genome.•NcGRA17 gene-knockout strain shows decreased virulence and aberrant morphology of parasitophorous ...vacuoles.•α-Helices are essential elements of NcGRA17 in the regulation of PV morphology.
Neospora caninum is an obligate intracellular protozoan parasite that infects a wide range of mammalian species, and particularly causes the reproductive loss in cattle. We identified a novel dense granule protein, N. caninum granule protein 17 (NcGRA17) using the CRISPR/cas9 genome editing system and studied its function. We generated the NcGRA17 knockout strain (ΔNcGRA17) and NcGRA17 complementary strain (iΔNcGRA17). Plaque assays and intracellular proliferation tests showed that the ΔNcGRA17 strain formed smaller plaques and had slower intracellular growth. Mouse virulence assay showed loss of virulence for the ΔNcGRA17 strain. We observed that the parasitophorous vacuoles (PVs) of NcGRA17-deficient parasites have aberrant morphology. To investigate the contribution of NcGRA17 α-helices to aberrant morphology of PVs, we transfected four truncated forms of NcGRA17 into NcGRA17 knockout strain and the phenotypes of these mutants were analysed. Lack of the N-terminal region (NT) failed to target the protein to dense granules, while NcGRA17 (Δα1)-HA, NcGRA17 (Δα2-4)-HA and NcGRA17 (Δα5-8)-HA were targeted to dense granules, but failed to rescue the aberrant PV morphology. Our results indicate that NcGRA17 as a dense granule protein determines PV morphology and pathogenicity, and α-helices of NcGRA17 may be responsible for the aberrant morphology of N. caninum PVs.
The seroprevalence and risk factors for exposure to Neospora caninum and Neospora hughesi in broodmares in Ontario were investigated. Sixty of the 219 (27.4%) study broodmares were seropositive for ...N. caninum and 65/219 (29.7%) for N. hughesi with cut-offs of ≥1:40 and ≥1:160, respectively. Thirty-one of 63 participating farms (49.2%) had at least 1 broodmare seropositive for N. caninum. Thirty-three of the 63 (52.4%) participating farms had at least 1 broodmare positive for N. hughesi. Risk factors for N. caninum included presence of farm dogs (OR = 6.70; 95% CI = 2.14–20.97; p = 0.001), and high stocking density (OR = 2.83; 95% CI = 1.27–6.30; p = 0.011). Presence of livestock, excluding cattle, was associated with reduced risk of exposure (OR = 0.17; 95% CI = 0.06–0.53; p = 0.002). The only risk factor for exposure to N. hughesi was feeding hay on the ground in the paddock (OR = 4.31; 95% CI = 1.65–11.22; p = 0.003). This study demonstrated widespread exposure to Neospora spp. in broodmares in Ontario.
•Seroprevalence of Neospora caninum and Neospora hughesi in horses is 27.4% and 29.7%, respectively.•The presence of farm dogs and high stocking density increases the broodmares risk of exposure to N. caninum.•The presence of livestock (excluding cattle) decreases the broodmares risk of exposure to N. caninum.•Feeding hay on the ground is a risk factor for exposure to N. hughesi.
is a protozoan parasite closely related to
and has been studied for causing neuromuscular disease in dogs and abortions in cattle. It is recognized as one of the main transmissible causes of ...reproductive failure in cattle and consequent economic losses to the sector. In that sense, this study aimed to evaluate the role of Toll-like receptor 3 (TLR3)-TRIF-dependent resistance against
infection in mice. We observed that TLR3
and TRIF
mice presented higher parasite burdens, increased inflammatory lesions, and reduced production of interleukin 12p40 (IL-12p40), tumor necrosis factor (TNF), gamma interferon (IFN-γ), and nitric oxide (NO). Unlike those of
,
tachyzoites and RNA recruited TLR3 to the parasitophorous vacuole (PV) and translocated interferon response factor 3 (IRF3) to the nucleus. We also observed that
upregulated the expression of TRIF in murine macrophages, which in turn upregulated IFN-α and IFN-β in the presence of the parasite. Furthermore, TRIF
infected macrophages produced lower levels of IL-12p40, while exogenous IFN-α replacement was able to completely restore the production of this key cytokine. Our results show that the TLR3-TRIF signaling pathway enhances resistance against
infection in mice, since it improves Th1 immune responses that result in controlled parasitism and reduced tissue inflammation, which are hallmarks of the disease.
Neospora caninum in birds: A review de Barros, Luiz Daniel; Miura, Ana Carolina; Minutti, Ana Flávia ...
Parasitology international,
August 2018, 2018-Aug, 2018-08-00, Letnik:
67, Številka:
4
Journal Article
Recenzirano
Neospora caninum is an obligate intracellular protozoan parasite that infects domestic and wild animals. Canids are considered to be definitive hosts since they may shed oocysts into the environment ...through their feces. The disease is recognized as one of the major causes of bovine abortion worldwide, leading to important economic losses in the dairy and beef cattle industries. Previous studies have reported N. caninum infection in different species of birds; infection in birds has been associated with increased seroprevalence and reproductive problems in dairy cattle. Although the role of birds in the epidemiological cycle of neosporosis is unknown, birds are exposed to infection because they feed on the ground and could thus contribute to parasite dissemination. This review is focused on the current state of knowledge of neosporosis in birds.
•Some birds' species are considered intermediate hosts for Neospora caninum.•Serological studies have been reported antibodies against the parasite in birds.•The role of birds in the epidemiology of neosporosis is discussed.
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