Molecular identification of Cryptosporidium spp. isolated from dairy calves in the Northern region of Algeria

Cryptosporidium spp. is the most frequent agent in Algeria that causes neonatal diarrhea in calves, with high symptomatic diarrhea in pre-weaned dairy calves. The study aims to measure the prevalence, distribution, and genotype of Cryptosporidium-infected calves in one of Algeria's high milk production areas (North Central and Northeast). From 35 dairy cattle farms were selected 172 (77 with diarrheic and 95 without diarrheic symptoms) calves aged less than 60 days. Twenty-three farms (65.71%) were detected with cryptosporidiosis using a modified Ziehl-Neelsen stain, whereby 68 calves (39.53%) were obtained positive. The Copro-ELISA test gave an individual prevalence of (37.66%, 22.11%) in calves with diarrhea and asymptomatic calves, respectively. Fifty positive cases confirmed with the previous tests reconfirmed by the target of S18 gene (SSU rRNA), in addition to the sequencing, were obtained from species C. parvum in all the analyzed samples. The subgenotype of C. parvum was obtained by amplifying the target gene of gp60, successfully confirmed by C. parvum type II (IIaA15G2R, IIaA16G2R1, and IIaA17G2R1). Our results confirmed the frequency of cryptosporidiosis in dairy calves from farms in Northern Algeria, with a pathogenic role in the calves, with potential zoonotic risk from food contamination.