Survey of Streptococcus equi subsp. equi in Imported Draft Horses and SeM Genetic Analysis of Isolates

Abstract

imported Eleven asymptomatic horses from France tested positive on rPCR. Three S. equi strains were isolated from three individuals. We performed SeM genetic analysis on these three strains, in addition to four other strains isolated from Canadian draft horses and a Belgian riding horse that were developing strangles. The two strains from the French isolates were classified into a new SeM allelic group (SeM-200). Molecular phylogenetic tree analysis suggested that the French and Belgian strains were closely related and classified into different clus-ters from the Canadian strains. This study identified asymptomatic carriers of strangles among imported draft horses. ─