Isolation of Streptococcus thoraltensis from rabbit faeces.

Bacteria were isolated from rabbit faeces using equine caecal fluid as a growth medium. Two new isolates of the genus Streptococcus are described in terms of their biochemical properties. One of these has a 16S rRNA gene with 97.7%, and the other 98.5%, identity to Streptococcus thoraltensis. While S. thoraltensis has been described in the intestinal tract of pigs, it is generally considered to inhabit the porcine genital tract. The biochemical properties of these bacteria indicate that both new isolates showed an ability to digest xylose, an adaptation beneficial for survival in a niche where much of the nutrient supply is of plant origin. Moreover, having bacteria able to digest xylose in the digestive tract should be beneficial to the rabbit, allowing more effective utilisation and digestion of food. This work provides one of the few examples of an analysis of the physiological properties of a bacterium found in the hindgut of the rabbit. By building up a number of such studies, the mechanisms of bacterial digestion in the rabbit will become better understood.