부산대학교 도서관

Among human faecal bacteria, many members of theClostridium leptumsubgroup are fibrolytic and butyrate producing microorganisms thereby contributing to processes important to colonic health. Yet this phylogenetic subgroup remains poorly described to date. To improve detection and description of members of theC. leptumsubgroup, the Clep 866 group probe was developed. Its association with probes targeting theClostridium viridecluster (Cvir 1414) andEubacterium desmolansspecies (Edes 635) allowed for the first time the detection of all members found in this phylogenetic group in human faecal microbiota. A species-specific probe was also designed to detect members of theRuminococcus callidusspecies (Rcal 733). The design of signature regions was based on alignment of 16S rRNA sequences isolated from faeces of five healthy adults. Furthermore, an oligonucleotide competitor strategy was developed in order to improve the specificity of the probes formerly validated or designed in this study. The oligonucleotide probes were tested using a collection of target and non-target strains using FISH combined with flow cytometry. These new probes were added to a panel of 18 phylogenetic probes selected to describe faecal microbiota composition in 21 human faeces of healthy adults.Clostridium leptumsubgroup represented 22% of the total faecal bacteria and codominated with members ofClostridium coccoidesgroup. The clusterFaecalibacterium prausnitziiwas the dominant component of theC. leptumsubgroup and 20% of the latter subgroup remained unidentified at the species level. [ABSTRACT FROM AUTHOR]