PHYLOGENETIC ANALYSIS AND IN-SITU IDENTIFICATION OF UNCULTIVATED SPIROCHETES FROM THE HINDGUT OF THE TERMITE MASTOTERMES DARWINIENSIS

Different small subunit ribosomal DNA (SSU rDNA) sequences of uncultiv ated spirochetes from the hindgut of the termite Mastotermes darwinien sis were determined and phylogenetically analysed. Starting with DNA i solated from hindgut contents we amplified SSU rDNA coding regions by PCR using bacteria- and spirochete-specific primers, respectively. Clo ning and sequencing of the amplification products resulted in 11 diffe rent spirochetal SSU rDNA sequences with similarity values of 81.8% to 99.0% to each other. Phylogenetic trees showed that the obtained sequ ences are related to the genus Treponema with 84.0% to 91.1% similarit y to Treponema spec. H1 and Spirochaeta stenostrepta as their nearest relatives among the cultivated spirochetes. Using fluorescence in situ hybridisation one of the SSU rDNA sequences could be assigned to a la rge spirochete. So at least one of the large hindgut spirochetes uniqu e in termite hindguts and assigned to the genera Hollandina, Pillotina , Clevelandina or Diplocalyx phylogenetically belongs to the treponeme cluster of spirochetes.