Pathogenesis of Bovine Neosporosis

Dubey, J. P.; Buxton, D.; Wouda, W.

doi:10.1016/j.jcpa.2005.11.004

Cited by 248 publications

(233 citation statements)

References 162 publications

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“…The total number of parasites in 400 ml of fresh bovine semen was less than 6 tachyzoites and the experimental infections in athymic mice with artificially contaminated semen indicate that at least 10 3 tachyzoites are necessary in bovine semen to induce an infection in an athymic BALB/c nu/nu mouse. An interesting issue of the present work was the insemination of seronegative cyclic heifers with pooled semen from infected bulls in order to evaluate the viability of parasites shed in 3/3 * 10 5 3/3 ** 10 3 (PBS) 2/2 *** 0 (semen) 0/3 * Two mice showed clinical signs and were sacrificed at 23 days post-inoculation. ** Three mice showed clinical signs and one animal at 23 days and two animals at 28 days post-inoculation were sacrificed.…”

Section: Discussionmentioning

confidence: 99%

“…A recent experimental study showed that the intrauterine infection via contaminated semen using 5 Â 10 4 tachyzoites caused persistent serum-specific antibody responses in some www.theriojournal.com Available online at www.sciencedirect.com Theriogenology 69 (2008) [905][906][907][908][909][910][911] heifers [4]. In persistently infected cattle, the reactivation (recrudescence) of the infection (caused by stress or immunosuppressive diseases) or ingestion of sporulated N. caninum oocysts could result in parasitaemia, leading to the dissemination of N. caninum throughout the body, including the genital tract [5]. In bulls, this fact could increase the number of parasites in semen and thus, lead to venereal infection risk.…”

Section: Introductionmentioning

confidence: 99%

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Effects of re-infection with Neospora caninum in bulls on parasite detection in semen and blood and immunological responses

et al. 2008

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Three bulls with experimentally induced primary infection with Neospora caninum were re-infected intravenously with 10 8 live N. caninum tachyzoites of the NC-1 isolate at 300 days post-infection to investigate the presence of N. caninum in semen and blood, and the associated immune responses. In parallel, three bulls with experimentally induced primary infection with N. caninum and three noninfected bulls were also monitored. Re-infected and infected bulls showed an intermittent presence of N. caninum DNA in semen with a parasite load ranging from 0.1 to 15.6 (mean 4.4) and 0.1 to 11.1 (mean 4.1) parasites/ml, respectively. Re-infected bulls showed significant and persistent serum-specific IgM and IgG antibody responses. Specific IgG levels were detected in seminal plasma of all infected bulls, but the magnitude of the response was significantly higher in re-infected rather than in chronically infected animals. The mean specific IFN-g levels in re-infected bulls were significantly increased as early as 3 and 7 days after experimental infection when compared to bulls in other groups. This study showed that the intermittent presence and parasite load of N. caninum in the semen of reinfected bulls is very similar to that reported in chronically infected animals. The protozoa could not be isolated from BALB/c nu/nu mice inoculated with PCR-positive semen samples and inseminated heifers with pooled semen samples did not show seroconversion. Plasma IFN-g level seems to be a good indicator of a recent N. caninum infection.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effects of re-infection with Neospora caninum in bulls on parasite detection in semen and blood and immunological responses

et al. 2008

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“…Neospora caninum has been recognised as the most important cause of abortion in cattle throughout the world (Dubey et al, 2006). Prenatal (vertical, congenital) and postnatal (horizontal, lateral) infection are the two modes of transmission in cattle.…”

Section: Introductionmentioning

confidence: 99%

Natural postnatal Neospora caninum infection in cattle can persist and lead to endogenous transplacental infection

Dijkstra

Lam

Bartels

et al. 2008

Veterinary Parasitology

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A serological follow-up study of 3.5 years duration was done of a dairy herd that had experienced a mass seroconversion to Neospora caninum following a point source exposure shortly before the 17th of January 2000. A total of 913 blood samples of 244 animals at seven sampling dates were used to investigate the seroprevalence dynamics in the herd.Most postnatally infected cattle remained seropositive during the period of investigation but 11 animals became seronegative after 6-27 months indicating transient infection. Six animals seroconverted later than the main group of 45 animals and 5 animals became seronegative after at least two seropositive records possibly due to a low infection dose or difference in the haplotypes of the infected animals. In total 58% (14/24) of the offspring of postnatally infected dams was seropositive. Nine of 16 (56%) daughters originating from inseminations after the postnatal infection of their dams were seropositive indicating endogenous transplacental infection. #

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“…Tanto a transmissão horizontal quanto a transmissão vertical são importantes rotas no desenvolvimento da infecção, vitais para a manutenção do parasita e circulação no hospedeiro (Dubey et al 2006).…”

Section: Introductionunclassified

Desempenho reprodutivo entre receptoras bovinas não contaminadas e naturalmente infectadas por Neospora caninum, após a transferência de embriões

Sturaro

Zanenga²,

Pedroso³

et al. 2013

Pesq. Vet. Bras.

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Pathogenesis of Bovine Neosporosis

Cited by 248 publications

References 162 publications

Effects of re-infection with Neospora caninum in bulls on parasite detection in semen and blood and immunological responses

Effects of re-infection with Neospora caninum in bulls on parasite detection in semen and blood and immunological responses

Natural postnatal Neospora caninum infection in cattle can persist and lead to endogenous transplacental infection

Desempenho reprodutivo entre receptoras bovinas não contaminadas e naturalmente infectadas por Neospora caninum, após a transferência de embriões

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