First detection and molecular identification of Neospora caninum from naturally infected cattle and sheep in North Africa

Abstract

Neosporosis, caused by the protozoan Neospora caninum, is a major cause of reproductive failure in ruminants causing enormous economic losses. The objective of this study was to estimate the infection rate and molecular identification of N. caninum in Tunisian cattle and sheep. A total number of 348 meat samples were collected from 150 cows and 198 ewes slaughtered in the regional slaughterhouse of Béja (North-west Tunisia) and tested for the presence of N. caninum ITS1 gene using PCR followed by sequencing of some PCR products. A phylogenetic tree was then constructed to compare the partial sequences of the ITS1 gene with GenBank sequences. The overall molecular infection prevalence of N. caninum was significantly higher in cattle than in sheep (22 and 10.6%, respectively, p = .003). In sheep, the highest prevalence was observed in the northern Béja locality (31.2 ± 16.1), with the Noire de Thibar breed as the most infected sheep breed (31.7 ± 14.2%) (p < .001). In cattle, there were no differences in the molecular prevalence of N. caninum according to breeds and localities. The association between age and N. caninum molecular prevalence was statistically significant in both species; the highest prevalence was observed in sheep of more than one year of age (19.4 ± 9.1%), and in cattle between two and eight years of age (28.8 ± 10.9%). Comparison of the partial sequences of the ITS1 gene revealed 96%-100% similarity among our N. caninum amplicon and those deposited in GenBank. To our knowledge, this is the first detection and molecular identification of N. caninum in sheep and cattle in North Africa. This information is pertinent in designing control programmes that would reduce economic losses in the livestock industry.

Keywords: Neospora caninum; North Africa; Tunisia; cattle; meat; sheep.