PHYLOGENETIC EVIDENCE THAT THE GRAM-NEGATIVE NONSPORULATING BACTERIUMTISSIERELLA (BACTEROIDES) PRAEACUTA IS A MEMBER OF THE CLOSTRIDIUM SUBPHYLUM OF THE GRAM-POSITIVE BACTERIA AND DESCRIPTION OF TISSIERELLA-CREATININI SP-NOV

The 16S rRNA gene sequence of the type strain of Tissierella praeacuta (formerly Bacteroides praeacutus) was determined by PCR direct sequen cing, A comparative sequence analysis showed that T. praeacuta is a me mber of the Clostridium subphylum of the gram-positive bacteria and ha s 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. Far row, Int. J. Syst. Bacteriol. 44:812-826, 1994), Although T. praeacuta is gram negative and does not produce endospores, 16S rRNA sequence d ata showed that it is closely related genealogically (level of sequenc e similarity, 99.9%) to Clostridium hastiforme. On the basis of our re sults and the results of previous studies, a second species of Tissier ella, Tissierella creatinini sp, nov., is described.