Endogenous transplacental transmission of Neospora caninum during successive pregnancies across three generations of naturally infected sheep

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.

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Endogenous and exogenous transplacental transmission of Neospora caninum – how the route of transmission impacts on epidemiology and control of disease

Parasitology ◽

10.1017/s0031182009990588 ◽

2009 ◽

Vol 136 (14) ◽

pp. 1895-1900 ◽

Cited By ~ 69

Author(s):

D. J. L. WILLIAMS ◽

C. S. HARTLEY ◽

C. BJÖRKMAN ◽

A. J. TREES

Keyword(s):

Immune Response ◽

Vertical Transmission ◽

Neospora Caninum ◽

Protozoan Parasite ◽

Transplacental Transmission ◽

Highly Efficient ◽

Route Of Transmission ◽

And Control

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.

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Experimental infection with Neospora caninum in pregnant bitches

Revista Brasileira de Parasitologia Veterinária ◽

10.1590/s1984-29612012000300010 ◽

2012 ◽

Vol 21 (3) ◽

pp. 232-236 ◽

Cited By ~ 8

Author(s):

Guacyara Tenorio Cavalcante ◽

Rodrigo Martins Soares ◽

Sandra Mayumi Nishi ◽

Stéfano Carlo Filippo Hagen ◽

Camila Infantoni Vannucchi ◽

...

Keyword(s):

Nested Pcr ◽

Fragment Length Polymorphism ◽

Indirect Fluorescent Antibody Test ◽

Neospora Caninum ◽

Fluorescent Antibody ◽

Antibody Test ◽

Transplacental Transmission ◽

Nested Polymerase Chain Reaction ◽

The Central Nervous System ◽

Polymerase Chain

In this study, transplacental transmission of Neospora caninum in bitches at different stages of pregnancy was evaluated. Three bitches were inoculated in the 3rd week and three in the 6th week of gestation with 10(8) tachyzoites of N. caninum (Nc-1 strain). All the infected bitches and at least one of their offspring presented anti-N. caninum antibodies according to the indirect fluorescent antibody test (IFAT > 400). The pups and their mothers were sacrificed and tissues from the central nervous system (CNS), popliteal lymph nodes, skeletal muscle, brain, lungs, heart and liver were analyzed for the presence of N. caninum using the nested polymerase chain reaction (nested PCR), restriction fragment length polymorphism (RFLP) and immunohistochemistry (IHC). The parasite was found in the pups in lymph node, CNS, heart and liver tissues using nested PCR. There was no difference in perinatal mortality between the offspring from bitches infected in the 3rd week of gestation (60%) and in the 6th week (53.8%).

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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

Parasitology ◽

10.1017/s0031182016000056 ◽

2016 ◽

Vol 143 (5) ◽

pp. 606-616 ◽

Cited By ~ 8

Author(s):

ADRIANA AGUADO-MARTÍNEZ ◽

AFONSO P. BASTO ◽

JOACHIM MÜLLER ◽

VRENI BALMER ◽

VERA MANSER ◽

...

Keyword(s):

Immune Response ◽

Neospora Caninum ◽

Chimeric Protein ◽

Cell Immune Response ◽

Transplacental Transmission ◽

Toll Like Receptor ◽

T Helper ◽

Adaptive Immune ◽

Toll Like Receptor 2 ◽

Th 1

SUMMARYImmunoprophylactic 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. In contrast to Mic3-1-R, OprI-MIC3-1-R significantly activated bone-marrow dendritic cells from naïve mice. Mice immunized with OprI-Mic3-1-R induced an immune response with mixed T helper (Th)1 and Th2 properties (high levels of both immunoglobulin (Ig)G1 and IgG2a and of interleukin (IL)-10, IL-12(p70) and interferon-γ responses) whereas Mic3-1-R+saponin induced a clear Th2-biased response (low IgG2a and high IL-4 and IL-10). After mating and challenge with N. caninum, increased expression of interferon-γ was only found in placentas from OprI-Mic3-1-R immunized dams. However, no protection against vertical transmission and neonatal mortality was observed in either of the two groups. These results indicated that more exhaustive studies must be done to elucidate the immune mechanisms associated with transplacental transmission. Antigen linkage to TLR2-ligands, such as OprI, is a useful tool to investigate this enigma by reorienting the innate and adaptive immune responses against other candidate antigens in future studies.

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