Phylogenetics and Pathogenicity of Balantioides coli Isolates in Vietnamese Weaned Pigs

Purpose This study aimed to investigate the diversity of Balantioides coli ( B. coli ) based on the 18S rDNA of isolates collected from weaned pigs with diarrhea and then select a B. coli isolate to determine its pathogenicity in weaned pigs through experimental infection. Methods The genetic analysis of field-isolated B. coli strains was based on sequencing of the partial 18S rDNA genetic fragment and the pathogenicity of an isolate of B. coli (DN2018-2-DTD) was identified through an experimental infection. Results The fourteen B. coli isolates shared 98.47–100% nucleotide similarity and were divided into two clades in a phylogenetic tree. In an infection experiment, a slight increase in the body temperature was identified in two infected groups as compared to that in the control group ( P