Isolation and molecular characterization of four novel Neospora caninum strains
Neospora caninum causes neosporosis, a leading cause of bovine abortion worldwide. Uruguay is a developing economy in South America that produces milk to feed seven times its population annually. Naturally, dairy production is paramount to the country’s economy, and bovine reproductive failure impacts it profoundly. Recent studies demonstrated that the vast majority of infectious abortions in dairy cows are caused by N. caninum. To delve into the local situation and contextualize it within the international standing, we set out to characterize the Uruguayan N. caninum strains. For this, we isolated four distinct strains and determined by microsatellite typing that these represent three unique genetic lineages, distinct from those reported previously in the region or elsewhere. An unbiased analysis of the current worldwide genetic diversity of N. caninum strains known, whereby six typing clusters can be resolved, revealed that three of the four Uruguayan strains group closely with regional strains from Argentina and Brazil. The remaining strain groups in an unrelated genetic cluster, suggesting multiple origins of the local strains. Microsatellite typing of N. caninum DNA from fetuses opportunistically collected from local dairy farms correlated more often with one of the isolates. Overall, our results contribute to further understanding of genetic diversity among strains of N. caninum both regionally and worldwide.
KeywordsApicomplexa Bovine abortion Neospora Microsatellite Genetic diversity Animal health
Analysis of molecular variance
Discriminant analysis of principal components
Dulbecco’s modified Eagle’s medium
Human foreskin fibroblast
Principal component analysis
We are thankful to Prando Moore, Lucía Campero, Cecilia Venturini, Luis Miguel Ortega-Mora, and Javier Regidor-Cerrillo for their helpful suggestions on isolation protocols and genetic analysis, and to Atilio Deana and Ivana Faccini for their contribution in assembling the Neospora consortium in Uruguay. We also thank Jan Shivers from the University of Minnesota Veterinary Diagnostic Laboratory for sharing the immunohistochemistry procedure, Francesca Chianini from Moredun Research Institute for gently providing the positive control for the immunohistochemistry, Yisell Perdomo from INIA for the technical assistance with the histochemical and immunohistochemical techniques, and Virginia Aráoz, Ricardo Costa, and Bruno López from INIA for the valuable assistance with the field work.
This project was funded by grant FSSA_X_2014_1_106026 from the Uruguayan National Agency for Research and Innovation (ANII). A.C., C.S., and M.M.R. are supported by doctoral fellowships from ANII. M.E.F. is supported by a Calmette & Yersin fellowship from the Institut Pasteur International Network (RIIP). M.C., L.B., P.F., F.G., F.R.-C., O.P., M.E.F., and C.R. are researchers from the Sistema Nacional de Investigadores (SNI).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
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