scholarly journals From Signaling Pathways to Distinct Immune Responses: Key Factors for Establishing or Combating Neospora caninum Infection in Different Susceptible Hosts

Pathogens ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 384 ◽  
Author(s):  
Ragab M. Fereig ◽  
Yoshifumi Nishikawa

Neospora caninum is an intracellular protozoan parasite affecting numerous animal species. It induces significant economic losses because of abortion and neonatal abnormalities in cattle. In case of infection, the parasite secretes numerous arsenals to establish a successful infection in the host cell. In the same context but for a different purpose, the host resorts to different strategies to eliminate the invading parasite. During this battle, numerous key factors from both parasite and host sides are produced and interact for the maintaining and vanishing of the infection, respectively. Although several reviews have highlighted the role of different compartments of the immune system against N. caninum infection, each one of them has mostly targeted specific points related to the immune component and animal host. Thus, in the current review, we will focus on effector molecules derived from the host cell or the parasite using a comprehensive survey method from previous reports. According to our knowledge, this is the first review that highlights and discusses immune response at the host cell–parasite molecular interface against N. caninum infection in different susceptible hosts.

2019 ◽  
Vol 87 (4) ◽  
Author(s):  
Vanessa dos Santos Miranda ◽  
Flávia Batista Ferreira França ◽  
Mylla Spirandelli da Costa ◽  
Vanessa Resende Souza Silva ◽  
Caroline Martins Mota ◽  
...  

ABSTRACT Neospora caninum is a protozoan parasite closely related to Toxoplasma gondii 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 N. caninum 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 T. gondii, N. caninum tachyzoites and RNA recruited TLR3 to the parasitophorous vacuole (PV) and translocated interferon response factor 3 (IRF3) to the nucleus. We also observed that N. caninum 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 N. caninum infection in mice, since it improves Th1 immune responses that result in controlled parasitism and reduced tissue inflammation, which are hallmarks of the disease.


2018 ◽  
Author(s):  
Vanessa dos Santos Miranda ◽  
Flávia Batista Ferreira França ◽  
Mylla Spirandelli da Costa ◽  
Vanessa Resende Souza Silva ◽  
Caroline Martins Mota ◽  
...  

AbstractNeospora caninum is a protozoan parasite closely related to Toxoplasma gondii and has been studied for causing neuromuscular disease in dogs and abortions in cattle. It is recognized as the major cause of economic losses in bovine products. In that sense, this study aimed to evaluate the role of TLR3-TRIF dependent resistance against N. caninum infection. We observed that TLR3−/− and TRIF−/− mice presented higher parasite burden, increased inflammatory lesions and reduced production of IL-12p40, TNF, IFN-γ, and NO. Differently from T. gondii, N. caninum tachyzoites and its RNA recruited TLR3 and IRF3 to the parasitophorous vacuole (PV). We observed that N. caninum upregulated the expression of TRIF in macrophages, which by its turn upregulated IFN-α and IFN-β in the presence of the parasite. Furthermore, TRIF−/− infected macrophages produced lower levels of IL-12p40 and IFN-α replacement was able to completely restore the production of this key cytokine. Our results have shown that TLR3-TRIF signaling pathway enhances resistance against N. caninum infection, since it improves Th1 immune responses that control parasitism and tissue inflammation, which are hallmarks of the disease.


2014 ◽  
Vol 59 (No. 12) ◽  
pp. 637-640 ◽  
Author(s):  
BY Jung ◽  
SH Lee ◽  
D. Kwak

Neospora caninum is a protozoan parasite that causes abortion in ruminants, including goats. The objective of the present study was to determine the seroprevalence of N. caninum in native Korean goats (Capra hircus coreanae). A commercial enzyme-linked immunosorbent assay kit was used to analyse 464 serum samples for the presence of N. caninum antibodies. Four samples (0.9%, 95% confidence intervals – CI: 0.0–1.7) were found to be positive for N. caninum antibodies. The seroprevalence was analysed according to age (less than to one year, young; more than or equal one year, adult; and unknown), sampling season (April to September, warm; October to March, cold), and region (northern, central, and southern). However, there were no statistically significant differences in seroprevalence according to age, season, and region (P > 0.05). This is the first report on the seroprevalence of N. caninum in native Korean goats. The results of this study indicate a nationwide distribution of N. caninum among goats, with a relatively low prevalence. Therefore, the implementation of integrated control strategies as well as measures for prevention and control of N. caninum infection among goats is recommended.


Pathogens ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 962
Author(s):  
Monica Leszkowicz Mazuz ◽  
Lea Mimoun ◽  
Gili Schvartz ◽  
Sharon Tirosh-Levy ◽  
Igor Savitzki ◽  
...  

In horses, Neospora caninum and Neospora hughesi have been associated with fetal loss, and neurological disease, respectively. This study investigated the role of Neospora spp. infection in equine abortion in Israel. The presence of anti-Neospora spp. antibodies was evaluated in 31 aborting mares by indirect fluorescent antibody test (IFAT) and the presence of parasite DNA in their aborted fetuses was evaluated by polymerase chain reaction (PCR), using two target loci (ITS1 and Nc5). The seroprevalence found in aborting mares was 70.9% and the prevalence by DNA detection in the aborted fetuses was 41.9%. Transplacental transmission from positive mares to their fetuses was 45.4% (10/22), while 33.3% (3/9) of fetuses of seronegative mares also tested positive for Neospora. The use of two PCR targets improved the sensitivity of parasite detection, and positive samples were identified by sequence analyses as N. caninum. These finding suggest that N. caninum could be a significant cause of abortion in horses, and that transplacental transmission in horses is an important way of transmission of N.caninum. The results presented here demonstrated the necessity to use several tests concurrently, including serological and molecular assays in order to confirm the involvement of Neospora in mare abortions.


2020 ◽  
Vol 32 (3) ◽  
pp. 401-408
Author(s):  
María B. Novoa ◽  
Beatriz S. Valentini ◽  
Macarena Sarli ◽  
Susana M. Torioni-de-Echaide ◽  
María E. Primo ◽  
...  

Neospora caninum is a protozoan parasite that causes abortion and important economic losses in cattle worldwide. There are no treatments or vaccines available; disease control is based on diagnosis and herd management strategies. We developed, validated, and evaluated under field conditions a competitive inhibition ELISA based on the truncated SAG1 protein (tSAG1), expressed in Escherichia coli, and the RafNeo5 monoclonal antibody (ciELISAtSAG1). A criterion based on the 3-y sequential serologic analysis of 230 dairy cows by IFAT was used as the gold standard. The assay was validated using 860 serum samples from cows that were consistently positive or negative by IFAT throughout the study period. ciELISAtSAG1 was then used to evaluate the prevalence of neosporosis in 16 beef cow herds (22 samples per herd, 352 total samples). The results were compared with those from IFAT and a commercial cELISA (cELISAVMRD). The ciELISAtSAG1 cutoff was ≥ 29%I, with a diagnostic sensitivity of 98.7% (95% CI = 96.8–99.7%) and a diagnostic specificity of 97.9% (95% CI = 96.4–99.0%). Concordance among IFAT, cELISAVMRD, and ciELISAtSAG1 was 90.3%. The agreement (κ) between ciELISAtSAG1 and the other 2 tests was ≥ 0.81. The overall prevalence of neosporosis in the 16 beef herds was 30% (range: 5–60%). The ciELISAtSAG1 could be useful for large-scale detection of anti– N. caninum antibodies in cattle and seroepidemiologic investigations, given its appropriate sensitivity and specificity, and the simplicity of production.


Parasitology ◽  
2012 ◽  
Vol 140 (3) ◽  
pp. 296-302 ◽  
Author(s):  
PETER STUART ◽  
ANNETTA ZINTL ◽  
THEO DE WAAL ◽  
GRACE MULCAHY ◽  
CONALL HAWKINS ◽  
...  

SUMMARYNeospora caninumis a protozoan parasite, primarily associated with bovine abortion. The only definitive hosts discovered to date are carnivores. This study aimed to identify the role of mammalian carnivores in the epidemiology of bovine neosporosis. A sample bank of serum, fecal and brain samples was established: American mink (Mustela vison), red foxes (Vulpes vulpes), pine martens (Martes martes), badgers (Meles meles), stoats (Mustela erminea), otters (Lutra lutra) and feral ferrets (Mustela putorius). Approximately 1% of mink and 1% of fox samples were positive by IFAT. According to PCR analysis of DNA extracted from brain tissue, 3% of the mink, 4% of the otters and 6% of the foxes examined were infected withN. caninum.All fecal samples tested negative forN. caninumDNA (n = 311), suggesting that the species that tested positive were intermediate not definitive hosts. This is the first time that tissues from mustelids have tested positive forN. caninum. The need to test 2 relatively large (∼200 mg) targeted parts of the brain to avoid false negatives was also identified. The relatively low prevalence ofN. caninumin Irish carnivores suggests that the local ecology of a species has an important influence on its epidemiological role.


Parasitology ◽  
2009 ◽  
Vol 136 (14) ◽  
pp. 1895-1900 ◽  
Author(s):  
D. J. L. WILLIAMS ◽  
C. S. HARTLEY ◽  
C. BJÖRKMAN ◽  
A. J. TREES

SUMMARYVertical transmission of the protozoan parasite, Neospora caninum is highly efficient and can take two forms – endogenous transplacental transmission resulting from activation of the quiescent bradyzoite stage during pregnancy or exogenous transplacental transmission resulting from ingestion of oocysts during pregnancy. Calves born carrying infection derived from either endogenous or exogenous transplacental transmission are capable of infecting their offspring when they start to breed. This review considers firstly the frequency with which exogenous and endogenous transmission occur, secondly the role of the immune response in controlling N. caninum infection and thirdly how the parasite persists in an immune-competent host and is re-activated during pregnancy.


2007 ◽  
Vol 20 (2) ◽  
pp. 323-367 ◽  
Author(s):  
J. P. Dubey ◽  
G. Schares ◽  
L. M. Ortega-Mora

SUMMARY Neospora caninum is a protozoan parasite of animals. Until 1988, it was misidentified as Toxoplasma gondii. Since its first recognition in dogs in 1984 and the description of the 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. Although antibodies to N. caninum have been reported, the parasite has not been detected in human tissues. Thus, the zoonotic potential is uncertain. This review is focused mainly on the epidemiology and control of neosporosis in cattle, but worldwide seroprevalences of N. caninum in animals and humans are tabulated. The role of wildlife in the life cycle of N. caninum and strategies for the control of neosporosis in cattle are discussed.


2014 ◽  
Vol 59 (2) ◽  
Author(s):  
Tawin Inpankaew ◽  
Sathaporn Jittapalapong ◽  
Thomas Mitchell ◽  
Chainirun Sununta ◽  
Ikuo Igarashi ◽  
...  

AbstractNeospora caninum, an obligate intracellular protozoan parasite, is the causative agent of neosporosis, recognized as a major cause of bovine abortion around the world. Thailand is a developing agricultural country located in Southeast Asia. Livestock developments particularly in dairy cows of this country have been hampered by low productivity including milk and slow growth rate due to the impact of many pathogens including N. caninum. Currently, there is no effective method for control of neosporosis since there is less information regarding current status of infections. The objective of this study was to investigate the seroprevalence of neosporosis in dairy cows of the northern part of Thailand. During 2006–2007, the sera of 642 cows from 42 small farm holders with the top three highest consensus of dairy farms in the northern provinces, such as Chiang Rai, Chiang Mai and Lumpang were collected and performed tests. Antibodies to N. caninum were assayed by enzyme-linked immunosorbent assay (ELISA) with recombinant N. caninum surface antigen 1 (NcSAG1) and indirect fluorescent antibody test (IFAT). The overall prevalence of N. caninum infection in this study was 46.9% (301/642) by ELISA and 34.3% (220/642) by IFAT.


2015 ◽  
Vol 46 (4) ◽  
pp. 654-659 ◽  
Author(s):  
Maiara Sanitá Tafner Ferreira ◽  
Fernanda Silveira Flores Vogel ◽  
Luis Antonio Sangioni ◽  
Augusto Weber ◽  
Patricia Bräunig ◽  
...  

ABSTRACT: Neosporosis is a parasitic disease caused by the protozoan Neospora caninum which results in major economic losses for cattle breeding due to abortion and other reproductive disorders. Gerbils (Meriones unguiculatus) are commonly used as experimental models for neosporosis due to their high susceptibility to N. caninum infection, both by oocysts ingestion as by tachyzoites/bradyzoites parenteral inoculation. However, the risk of transmission by tachyzoites ingestion is not fully elucidated. In this study, infection of neonate gerbils by N. caninum (NC-1 strain) tachyzoites inoculated by the oral route and the parasite distribution in gerbils' tissues were evaluated by protozoan DNA detection. Seventeen neonate gerbils, aged 4-5 days, were inoculated with 4x105 tachyzoites by the oral route and one gerbil was kept as uninfected control. N. caninum DNA was detected in 100% of the inoculated gerbils, showing that the oral route is effective as a potential route of infection of neonates by N. caninum tachyzoites. N. caninum DNA was reported in all organs evaluated (heart, lungs, kidneys, liver, spleen and brain), with different frequencies. These results showed systemically distributed infection of neonate gerbils after oral inoculation of tachyzoites.


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