title: Dynamics and diversity of the 'Atopobium cluster' in the human faecal microbiota, and phenotypic characterization of 'Atopobium cluster' isolates.
abstract: This study monitored the dynamics and diversity of the human faecal 'Atopobium cluster' over a 3-month period using a polyphasic approach. Fresh faecal samples were collected fortnightly from 13 healthy donors (six males and seven females) aged between 26 and 61 years. FISH was used to enumerate total (EUB338mix) and 'Atopobium cluster' (ATO291) bacteria, with counts ranging between 1.12×10(11) and 9.95×10(11), and 1.03×10(9) and 1.16×10(11) cells (g dry weight faeces)(-1), respectively. The 'Atopobium cluster' population represented 0.2-22 % of the total bacteria, with proportions donor-dependent. Denaturing gradient gel electrophoresis (DGGE) using 'Atopobium cluster'-specific primers demonstrated faecal populations of these bacteria were relatively stable, with bands identified as Collinsella aerofaciens, Collinsella intestinalis/Collinsella stercoris, Collinsella tanakaei, Coriobacteriaceae sp. PEAV3-3, Eggerthella lenta, Gordonibacter pamelaeae, Olsenella profusa, Olsenella uli and Paraeggerthella hongkongensis in the DGGE profiles of individuals. Colony PCR was used to identify 'Atopobium cluster' bacteria isolated from faeces (n = 224 isolates). 16S rRNA gene sequence analysis of isolates demonstrated Collinsella aerofaciens represented the predominant (88 % of isolates) member of the 'Atopobium cluster' found in human faeces, being found in nine individuals. Eggerthella lenta was identified in three individuals (3.6 % of isolates). Isolates of Collinsella tanakaei, an 'Enorma' sp. and representatives of novel species belonging to the 'Atopobium cluster' were also identified in the study. Phenotypic characterization of the isolates demonstrated their highly saccharolytic nature and heterogeneous phenotypic profiles, and 97 % of the isolates displayed lipase activity.
authors.affiliation: Microbial Ecology & Health Group, Department of Food and Nutritional Sciences, School of Chemistry, Food and Pharmacy, University of Reading, Whiteknights, PO Box 226, Reading RG6 6AP, UK.
authors.forename: Thanikan
authors.initials: T
authors.lastname: Thorasin
authors.affiliation: Department of Biomedical Sciences, Faculty of Science and Technology, University of Westminster, 115 New Cavendish Street, London W1W 6UW, UK.
authors.forename: Lesley
authors.initials: L
authors.lastname: Hoyles
authors.affiliation: Microbial Ecology & Health Group, Department of Food and Nutritional Sciences, School of Chemistry, Food and Pharmacy, University of Reading, Whiteknights, PO Box 226, Reading RG6 6AP, UK a.l.mccartney@reading.ac.uk.
authors.forename: Anne L
authors.initials: AL
authors.lastname: McCartney
mesh_terms: D039903:Actinobacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D000328:Adult; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D044822:Biodiversity; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D005243:Feces / Q000382:microbiology*; D005260:Female; D006801:Humans; D008297:Male; D064307:Microbiota; D008875:Middle Aged; D008969:Molecular Sequence Data; D010641:Phenotype; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S