RECLASSIFICATION OF CLOSTRIDIUM CLUSTER XVIII AND DESCRIPTION OF THREE NOVEL TAXA WITHIN THE GRAM-POSITIVE ANAEROBIC COCCI

Abstract

Current taxonomic classification approaches employ a polyphasic approach to characterize novel species. Most study morphological and biochemical characteristics along with chemotaxonomic characteristics to aid in the general assignment of species to the correct taxa. Numerous clinically isolated species benefit from such studies. One of them is the microbial community in the human gastrointestinal tract (GIT). Specifically, one of its dominant phyla, the phylum Firmicutes. Over the years, polyphasic studies have tried to obtain characteristics to correctly classify them taxonomically and to understand their relationship in the GIT, and so far 16S rRNA gene sequencing has caused significant taxonomic changes. Two important groups, the Clostridia and the Gram-positive anaerobic cocci (GPAC), will be discussed though out this thesis. The current taxonomic changes each one of them is currently undergoing are addressed and further changes proposed.