The evaluation of attenuated Neospora caninum by long-term passages on murine macrophage cell line in prevention of vertical transmission in mice

Copyright © 2020 Elsevier B.V. All rights reserved..

To date, there is no effective vaccine to prevent abortion or vertical transmission associated with neosporosis in cattle. In the present study, the efficacy of a live experimental vaccine of Neospora caninum attenuated (NCa) by long-term serial passages on a murine macrophage cell line was evaluated in the prevention of vertical transmission and abortion in the mouse model. Forty non-pregnant mice were randomly divided into four equal groups including non-immunized/challenged (injected with PBS); positive control (inoculated with un-attenuated NC-1 tachyzoites); immunized/challenged (inoculated with NCa attenuated strain) and immunized/non-challenged or vaccinated (inoculated with NCa) groups. Following pregnancy synchronization, both the immunized and control mice were challenged with virulent live NC-1 tachyzoites (2.5 × 106) in the mid-pregnancy stage. The number of abortions and post-natal pup mortalities was recorded. Serological, molecular, and histopathologic examinations were employed to evaluate the efficacy of the vaccine and the vertical transmission rates. Results indicated that the live attenuated N. caninum strain (NCa) could significantly reduce the risk of abnormal parturitions and fetal mortality in the vaccinated group (20 %) compared to the non-immunized/challenged group (80 %). Also, the NCa strain reduced the lesion score in the brain of the offspring (0.3 vs 1.9) compared to the non-immunized/challenged group (P < 0.05). The molecular assay showed a decrease in the parasite DNA detection rates from 83 % and 77 % in the non-immunized/challenged group to 27 % and 0 % in the vaccine group in the brain and liver tissues, respectively. While in the immunized/non-challenged group no parasite DNA was detected in the brain tissue samples of the pups. Serological analyses showed that NCa strain was able to stimulate the humoral immunity and create effective protection against neosporosis with a moderate systemic IFN-γ response. In conclusion, the NCa strain could significantly (P < 0.05) reduce the risk of vertical transmission and proved to be a safe vaccine while conferring significant levels of protection in the laboratory mice.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:283

Enthalten in:

Veterinary parasitology - 283(2020) vom: 10. Juli, Seite 109171

Sprache:

Englisch

Beteiligte Personen:

Amini, Laleh [VerfasserIn]
Namavari, Mehdi [VerfasserIn]
Khodakaram-Tafti, Azizollah [VerfasserIn]
Divar, Mohammad Reza [VerfasserIn]
Hosseini, Seyed Mohammad Hossein [VerfasserIn]

Links:

Volltext

Themen:

Fungal Vaccines
Histopathology
Journal Article
Live attenuated vaccine
Neospora caninum
Pregnant mice
Vaccines, Attenuated

Anmerkungen:

Date Completed 01.04.2021

Date Revised 01.04.2021

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.vetpar.2020.109171

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM312008988