title: Neospora caninum: Chronic and congenital infection in consecutive pregnancies of mice.
abstract: Neospora caninum, the causative agent of bovine neosporosis is the major cause of abortion in cattle worldwide. The principal route of transmission is via in utero infection of the offspring. Congenitally-infected dams remain persistently infected for life and might undergo abortions in consecutive pregnancies. In the present study, the effect of N. caninum in chronic and congenital infection was examined. CD1 mice were infected intra-peritoneally with live tachyzoites of the NcIs491 isolate, while non-infected mice served as a control. There were no clinical signs of infection observed following inoculation, but high titers of specific anti- N. caninum antibodies were detected. A month after infection, when chronic-infection was established, mice were mated. Fertility, litter size and mortality rate were monitored within two generations of four consecutive pregnancies. During a nine months period of the study all females maintained high level of antibodies, while the non- infected control mice remained seronegative. There was no difference in the fertility rate of the dams, or in the litter size of infected and control mice. Mortality of offspring of the first and second generations of the infected dams was observed within the two first weeks of life. The vertical transmission was analyzed by PCR assay of offspring brains. PCR positive results were found in all 13 litters of the first generation tested during four consecutive pregnancies. The rate of vertical transmission slightly decreased in successive pregnancies being 74.2%, 59.5%, 48.1% and 40% for the first to fourth pregnancies respectively. In the second generation 21 out of 28 litters were found positive and the overall rate of vertical transmission was 28.5%. In chronically and congenitally infected dams N. caninum infection was maintained during all successive pregnancies for about 9 months. The results show that CD-1 outbred mice are a suitable model for studying chronic and congenital neosporosis.
authors.affiliation: Division of Parasitology, Kimron Veterinary Institute, P.O.B. 12, Bet Dagan 50250, Israel; Department of Microbiology and Molecular Genetics, The Kuvin Center for the Study of Infectious and Tropical Diseases, The Hebrew University of Jerusalem, Jerusalem, Israel. Electronic address: monica@int.gov.il.
authors.forename: Monica L
authors.initials: ML
authors.lastname: Mazuz
authors.affiliation: Division of Parasitology, Kimron Veterinary Institute, P.O.B. 12, Bet Dagan 50250, Israel.
authors.forename: Varda
authors.initials: V
authors.lastname: Shkap
authors.affiliation: Division of Parasitology, Kimron Veterinary Institute, P.O.B. 12, Bet Dagan 50250, Israel.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Wollkomirsky
authors.affiliation: Division of Parasitology, Kimron Veterinary Institute, P.O.B. 12, Bet Dagan 50250, Israel.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Leibovich
authors.affiliation: Division of Parasitology, Kimron Veterinary Institute, P.O.B. 12, Bet Dagan 50250, Israel.
authors.forename: Igor
authors.initials: I
authors.lastname: Savitsky
authors.affiliation: Division of Parasitology, Kimron Veterinary Institute, P.O.B. 12, Bet Dagan 50250, Israel.
authors.forename: Ludmila
authors.initials: L
authors.lastname: Fleiderovitz
authors.affiliation: Division of Parasitology, Kimron Veterinary Institute, P.O.B. 12, Bet Dagan 50250, Israel.
authors.forename: Sugar
authors.initials: S
authors.lastname: Noam
authors.affiliation: Division of Parasitology, Kimron Veterinary Institute, P.O.B. 12, Bet Dagan 50250, Israel.
authors.forename: Blinder
authors.initials: B
authors.lastname: Elena
authors.affiliation: Division of Parasitology, Kimron Veterinary Institute, P.O.B. 12, Bet Dagan 50250, Israel.
authors.forename: Thea
authors.initials: T
authors.lastname: Molad
authors.affiliation: Department of Microbiology and Molecular Genetics, The Kuvin Center for the Study of Infectious and Tropical Diseases, The Hebrew University of Jerusalem, Jerusalem, Israel.
authors.forename: Jacob
authors.initials: J
authors.lastname: Golenser
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D002908:Chronic Disease; D003048:Coccidiosis / Q000097:blood / Q000151:congenital* / Q000635:transmission*; D004195:Disease Models, Animal; D005260:Female; D018445:Infectious Disease Transmission, Vertical; D051379:Mice; D018688:Neospora / Q000502:physiology; D016133:Polymerase Chain Reaction; D011247:Pregnancy
chemical_list: D000913:Antibodies, Protozoan
keywords: Chronic infection; Congenital neosporosis; Mouse model; Neospora caninum