The Impact of BKI-1294 Therapy in Mice Infected With the Apicomplexan Parasite and Re-infected During Pregnancy.

Exposure of tachyzoites to BKI-1294 results in the formation of long-lived multinucleated complexes (MNCs). However, treatment of BALB/c mice with BKI-1294 shortly after infection during pregnancy was safe and profoundly reduced pup mortality and vertical transmission. We hypothesized that the formation of MNCs could trigger immune responses that contribute to BKI efficacy .

Virulence in Mice of a Type II Isolate Does Not Correlate With the Outcome of Experimental Infection in Pregnant Sheep.

is an apicomplexan parasite that infects almost all warm-blooded animals. Little is known about how the parasite virulence in mice extrapolates to other relevant hosts. In the current study, phenotype and behavior in mice and sheep of a type II isolate (TgShSp1) were compared with the reference type II isolate (TgME49).

Endochin-Like Quinolones Exhibit Promising Efficacy Against and in Experimentally Infected Pregnant Mice.

We report on the efficacy of selected endochin-like quinolones (ELQs) against tachyzoites grown in human foreskin fibroblasts (HFF), and in a pregnant BALB/c mouse model. Fourteen ELQs were screened against transgenic tachyzoites expressing β-galactosidase (Nc-βgal). Drugs were added concomitantly to infection and the values for 50% proliferation inhibition (IC) were determined after 3 days.

Immunization with a cocktail of antigens fused with OprI reduces Neospora caninum vertical transmission and postnatal mortality in mice.

OprI is an outer membrane lipoprotein from Pseudomonas aeruginosa, and when fused to a recombinant antigen, will exert adjuvant properties by engaging Toll-like receptor 2, leading to dendritic cell activation. Previous studies have shown that the Neospora caninum (Nc) antigens NcPDI, NcROP2 and NcROP40 are implicated in host cell interactions and are promising vaccine candidates. In two independent experiments, the efficacy of a polyvalent vaccine formulation composed of OprI-NcPDI, OprI-NcROP2 and OprI-NcROP40 (collectively named O-Ags) was assessed in non-pregnant and pregnant Balb/c mouse models challenged with tachyzoites of the high-virulence isolate Nc-Spain7.

Mercury exposure induces proinflammatory enzymes in vascular fibroblasts.

Introduction: Previous studies show that mercury exposure increases cardiovascular risk, although the underlying cellular mechanisms have still not been fully studied. The aim of this project is to study, in vascular fibroblasts (VF), the effect of HgCl exposure on the expression of enzymes involved in the synthesis of prostanoids and reactive oxygen species (ROS). These molecules have been shown to participate in the inflammatory response associated with cardiovascular diseases.

Neospora caninum in non-pregnant and pregnant mouse models: cross-talk between infection and immunity.

Neospora caninum is a cyst-forming coccidian which causes abortion in cattle, with a high economic impact globally. Vaccination is considered to be the most cost-effective strategy to control and prevent bovine neosporosis. However, there is no commercial vaccine available to date.

Development of a murine vertical transmission model for Toxoplasma gondii oocyst infection and studies on the efficacy of bumped kinase inhibitor (BKI)-1294 and the naphthoquinone buparvaquone against congenital toxoplasmosis.

Objectives: Establishment of a mouse model for congenital toxoplasmosis based on oral infection with oocysts from Toxoplasma gondii ME49 and its application for investigating chemotherapeutic options against congenital toxoplasmosis.

Methods: CD1 mice were mated, orally infected with 5, 25, 100, 500 or 2000 oocysts and monitored for clinical signs and survival of dams and pups until 4 weeks post partum . The parasite burden in infected mice was quantified by real-time PCR in lungs, brains and, in the case of surviving pups, also in eyes.

Two Novel Calcium-Dependent Protein Kinase 1 Inhibitors Interfere with Vertical Transmission in Mice Infected with Neospora caninum Tachyzoites.

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 (ICs) of 0.05 ± 0.

Vaccines for bovine neosporosis: current status and key aspects for development.

Bovine neosporosis is a worldwide concern due to its global distribution and great economic impact. Reproductive failure in cattle due to abortion leads to major economic losses associated with the disease. Currently, there is no treatment or vaccine available against abortion or transmission caused by Neospora caninum infection in cattle.

EFFECT OF DIFFERENT ECOSYSTEMS AND MANAGEMENT PRACTICES ON TOXOPLASMA GONDII AND NEOSPORA CANINUM INFECTIONS IN WILD RUMINANTS IN SPAIN.

Toxoplasma gondii and Neospora caninum are two major abortifacient protozoans in domestic small ruminants and cattle, respectively, and they also parasitize a wide range of wildlife. Numerous serosurveys have been conducted in wild ruminants worldwide. However, the potential effect of different ecosystems and management practices on these infections has not been investigated.

N-terminal fusion of a toll-like receptor 2-ligand to a Neospora caninum chimeric antigen efficiently modifies the properties of the specific immune response.

Immunoprophylactic products against neosporosis during pregnancy should induce an appropriately balanced immune response. In this respect, OprI, a bacterial lipoprotein targeting toll like receptor (TLR)2, provides promising adjuvant properties. We report on the manipulation of the innate and the T-cell immune response through the fusion of OprI with the Neospora caninum chimeric protein Mic3-1-R.

Repurposing of antiparasitic drugs: the hydroxy-naphthoquinone buparvaquone inhibits vertical transmission in the pregnant neosporosis mouse model.

The three anti-malarial drugs artemiside, artemisone, and mefloquine, and the naphthoquinone buparvaquone known to be active against theileriosis in cattle and Leishmania infections in rodents, were assessed for activity against Neospora caninum infection. All four compounds inhibited the proliferation of N. caninum tachyzoites in vitro with IC50 in the sub-micromolar range, but artemisone and buparvaquone were most effective (IC50 = 3 and 4.

Approaches for the vaccination and treatment of Neospora caninum infections in mice and ruminant models.

Neospora caninum is a leading cause of abortion in cattle, and is thus an important veterinary health problem of high economic significance. Vaccination has been considered a viable strategy to prevent bovine neosporosis. Different approaches have been investigated, and to date the most promising results have been achieved with live-attenuated vaccines.

In Vitro and In Vivo Effects of the Bumped Kinase Inhibitor 1294 in the Related Cyst-Forming Apicomplexans Toxoplasma gondii and Neospora caninum.

We report on the in vitro effects of the bumped kinase inhibitor 1294 (BKI-1294) in cultures of virulent Neospora caninum isolates Nc-Liverpool (Nc-Liv) and Nc-Spain7 and in two strains of Toxoplasma gondii (RH and ME49), all grown in human foreskin fibroblasts. In these parasites, BKI-1294 acted with 50% inhibitory concentrations (IC50s) ranging from 20 nM (T. gondii RH) to 360 nM (N.

Dose-dependent effects of experimental infection with the virulent Neospora caninum Nc-Spain7 isolate in a pregnant mouse model.

Pregnant BALB/c mice have been widely used as an in vivo model to study Neospora caninum infection biology and to provide proof-of-concept for assessments of drugs and vaccines against neosporosis. The fact that this model has been used with different isolates of variable virulence, varying infection routes and differing methods to prepare the parasites for infection, has rendered the comparison of results from different laboratories impossible. In most studies, mice were infected with similar number of parasites (2 × 10(6)) as employed in ruminant models (10(7) for cows and 10(6) for sheep), which seems inappropriate considering the enormous differences in the weight of these species.

Buparvaquone is active against Neospora caninum in vitro and in experimentally infected mice.

The naphthoquinone buparvaquone is currently the only drug used against theileriosis. Here, the effects of buparvaquone were investigated in vitro and in an experimental mouse model for Neospora caninum infection. In 4-day proliferation assays, buparvaquone efficiently inhibited N.

Toxoplasma gondii and Neospora caninum seroprevalences in domestic South American camelids of the Peruvian Andes.

The objective of this study was to investigate the presence of Toxoplasma gondii- and Neospora caninum-specific antibodies in domestic South American camelids (SAC) (llamas and alpacas) from the Peruvian Andes through a cross-sectional study. A wide panel of serum samples collected from 1,845 llamas and 2,874 alpacas from the two main SAC production areas of Peru was selected. Immunofluorescence antibody technique was employed to detect and titrate specific anti-T.

Seroprevalence of Besnoitia besnoiti infection and associated risk factors in cattle from an endemic region in Europe.

Bovine besnoitiosis, caused by the parasite Besnoitia besnoiti, is a chronic, debilitating disease with both cutaneous and systemic clinical signs that has re-emerged in Europe. This is the first random cross-sectional prevalence study of B. besnoiti infection in cattle carried out in an endemic area in Europe (Navarra, Spain).

Combination of monoclonal antibodies improves immunohistochemical diagnosis of Neospora caninum.

Histological analysis is commonly used for a conclusive diagnosis of neosporosis. Immunohistochemistry (IHC) using monoclonal (mAb) and polyclonal (pAb) antibodies can improve diagnosis; however, the use of pAb may induce cross-reactivity with other related parasites. The aims of this study were to compare the performance of mAbs and their combinations with that of pAb in IHC and evaluate the usefulness of mAb to identify Neospora caninum infection in aborted bovine fetal tissues.

Identification of Besnoitia besnoiti proteins that showed differences in abundance between tachyzoite and bradyzoite stages by difference gel electrophoresis.

Bovine besnoitiosis is a chronic and debilitating disease, caused by the apicomplexan parasite Besnoitia besnoiti. Infection of cattle by B. besnoiti is governed by the tachyzoite stage, which is related to acute infection, and the bradyzoite stage gathered into macroscopic cysts located in subcutaneous tissue in the skin, mucosal membranes and sclera conjunctiva and related to persistence and chronic infection.

Fertility in a high-altitude environment is compromised by luteal dysfunction: the relative roles of hypoxia and oxidative stress.

Background: At high altitudes, hypoxia, oxidative stress or both compromise sheep fertility. In the present work, we tested the relative effect of short- or long-term exposure to high altitude hypobaric hypoxia and oxidative stress on corpora luteal structure and function.

Methods: The growth dynamics of the corpora lutea during the estrous cycle were studied daily by ultrasonography in cycling sheep that were either native or naïve to high-altitude conditions and that were supplemented or not supplemented with antioxidant vitamins.

Mice congenitally infected with low-to-moderate virulence Neospora caninum isolates exhibited clinical reactivation during the mating period without transmission to the next generation.

Endogenous transplacental transmission (EnTT) is the major transmission route of Neospora caninum in cattle. Thus, the development of a standardised experimental model of EnTT is needed for more appropriate testing of parasite biology and control strategies. A recent study reported up to 40-50% EnTT rates in chronically infected dams with either high or low-to-moderate virulence isolates, although low fertility rates were observed in dams inoculated with the high virulence isolate.

Low rates of Neospora caninum infection reactivation during gestation are observed in both chronically and congenitally infected mice.

Endogenous transplacental transmission (EnTT) of Neospora caninum is the most common route of infection in cattle and occurs as a consequence of a reactivation of N. caninum infection that may lead to abortion or to the birth of congenitally infected calves. The reactivation of N.

Low efficacy of NcGRA7, NcSAG4, NcBSR4 and NcSRS9 formulated in poly-ε-caprolactone against Neospora caninum infection in mice.

The protective efficacy of vaccination with Neospora caninum recombinant antigens was evaluated in Balb/c pregnant and non-pregnant mouse models of neosporosis. A major immunodominant dense granule protein (NcGRA7) and three bradyzoite-specific surface antigens (NcSAG4, NcBSR4 and NcSRS9) were expressed in Escherichia coli and encapsulated within poly-ε-caprolactone (PCL) nanoparticles for the first time. Good efficiencies of entrapment (greater than 50%) were obtained for all encapsulated proteins.

Presence and molecular characterisation of Giardia and Cryptosporidium in alpacas (Vicugna pacos) from Peru.

The presence of Giardia and Cryptosporidium was investigated in 274 faecal samples of alpacas (Vicugna pacos) from 12 herds from Peru by immunofluorescence microscopy and PCR amplification and sequencing of fragments of the ssu-rRNA and β-giardin genes from Giardia spp., as well as the ssu-rRNA gene from Cryptosporidium spp. A total of 137 samples (50.