Phylogenetic evidence that the gram-negative nonsporulating bacterium Tissierella (Bacteroides) praeacuta is a member of the Clostridium subphylum of the gram-positive bacteria and description of Tissierella creatinini sp. nov.

ABSTRACT

The 16S rRNA gene sequence of the type strain of Tissierella praeacuta (formerly Bacteroides praeacutus) was determined by PCR direct sequencing. A comparative sequence analysis showed that T. praeacuta is a member of the Clostridium subphylum of the gram-positive bacteria and has a close phylogenetic affinity with the species that form Clostridium cluster XII (M. D. Collins, P. A. Lawson, A. Willems, J. J. Cordoba, J. Fernandez-Garayzabal, P. Garcia, J. Cai, H. Hippe, and J. A. E. Farrow, Int. J. Syst. Bacteriol. 44812-826, 1994). Although T. praeacuta is gram negative and does not produce endospores, 16S rRNA sequence data showed that it is closely related genealogically (level of sequence similarity, 99.9%) to Clostridium hastiforme. On the basis of our results and the results of previous studies, a second species of Tissierella, Tissierella creatinini sp. nov., is described.