Enterococcus asini sp. nov. isolated from the caecum of donkeys (Equus asinus).

Abstract

Several Gram-positive, non-spore-forming and non-motile bacteria consisting of pairs or chains of cocci were isolated during an investigation of the bacterial flora of the caecum of donkeys. Physiological and metabolic data indicated that the strains belong to the genus Enterococcus; phenotypic traits of these organisms were not consistent with any of the currently known Enterococcus species. 16S rRNA gene sequence analysis placed these strains in the genus Enterococcus. Their closest relatives are Enterococcus avium, Enterococcus faecium and Enterococcus pseudoavium with a sequence similarity of 97.4%. This group of strains can be differentiated from the other Enterococcus spp. by their phenotypic characteristics: strains do not grow in 6.5% NaCl; they do not produce acid from mannitol, sorbitol, sorbose, sucrose, raffinose, ribose and tagatose; they produce acid from D-xylose; they are able to utilize pyruvate; and they present a negative reaction on arginine. The name Enterococcus asini sp. nov. is proposed for these strains; the type strain is AS2T (= DSM 11492T).