doktorska disertacija
Stina Hedžet (Author), Maja Rupnik (Mentor), Tomaž Accetto (Co-mentor)

Abstract

Longitudinalne študije so pokazale, da je humana črevesna mikrobiota stabilna, pri čemer nekatere glavne bakterijske linije ali celo sevi vztrajajo več let. Pred kratkim so to opažanje razširili tudi na črevesne bakteriofage. V svojem delu smo se osredotočili na gojenje sevov Bacteroides in Phocaeicola ter njihovih bakteriofagov. Pri dveh zdravih prostovoljcih smo v dveh časovnih točkah potrdili obstojnost vrst in sevov iz rodu Bacteroides in Phocaeicola. Izolirali smo 31 genetsko različnih fagov, ki se uvrščajo v sedem različnih skupin, dve od teh bi lahko predstavljali popolnoma novi fagni družini. Poleg tega so bili bakteriofagi iz več skupin, čeprav so bili genetsko precej homogeni, sposobni okužiti seve, ki pripadajo različnim vrstam, izoliranim v več časovnih točkah vzorčenja in pri različnih prostovoljcih. Primerjava sevov in fagov, pridobljenih iz različnih prostovoljcev in v različnih časovnih obdobjih, je razkrila dolgoročno obstojnost bakterijskih linij, virusnih skupin in izrazito medvrstno infektivnost pridobljenih bakteriofagov. Predlagamo, da bi lahko možnost okužbe različnih vrst znotraj družine Bacteroidaceae prispevala k opaženi dolgoročni stabilnosti teh skupin fagov v črevesju. Bakterijske genome smo analizirali glede potencialne prisotnosti profagov ter opazovali njihovo dinamiko med časovnimi točkami. Identificirali smo 65 profagov, ki se uvrščajo v 4 skupine. Opisali smo njihovo stabilnost pri posameznem prostovoljcu in okužbo več bakterijskih vrst v daljšem časovnem obdobju, ki je skladna s širokim naborom gostiteljev, ki smo ga opazili pri izoliranih fagih. V in vitro sistemu za gojenje fekalne mikrobiote izbrani fagi niso vplivali na sestavo fekalne mikrobiote ter na stabilnost in prisotnost fagov v metaviromu.

Keywords

bakteriofagi;fagi;virom;črevesna mikrobiota;Bacteroides;Phocaeicola;profagi;

Data

Language: Slovenian
Year of publishing:
Typology: 2.08 - Doctoral Dissertation
Organization: UL BF - Biotechnical Faculty
Publisher: [S. Hedžet]
UDC: 602.3:578.347(043.3)
COBISS: 203833347 Link will open in a new window
Views: 207
Downloads: 52
Average score: 0 (0 votes)
Metadata: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Other data

Secondary language: English
Secondary title: Identification of bacteriophages from human gut microbiota
Secondary abstract: The longitudinal studies have found that the human gut microbiota is stable over time with some major bacterial lineages or even strains persisting for years. This was recently extended to gut bacteriophages using the metagenomic data. Here, we focused on cultivation of the major Bacteroidota of the human gut, the Bacteroides and Phocaeicola strains, and their bacteriophages from two healthy donors. The persistence of Bacteroides and Phocaeicola species and strains was confirmed. We have isolated 31 genetically different phages grouped into seven distinct clusters, two of which were new. Moreover, the bacteriophages from several groups, although being genetically quite homogeneous, had the ability to infect the strains belonging to different species isolated from several sampling time-points and different donors. We propose that the ability to infect several host species, which differ in their nutritional niches, may promote long-term persistence of dominant gut bacteriophage groups. Additionally, bacterial genomes were analyzed for the presence of potential prophages and their dynamics was observed between time points and donors. We identified 65 prophages, groupped into four clusters. Identified prophages were stable over the sampling period and could infect different bacterial species. The isolated phages were used in an in vitro system for the cultivation of fecal microbiota, where we studied their influence on the composition of the fecal microbiota and the stability and presence of phages in the metavirome.
Secondary keywords: bacteriophages;phages;virome;gut microbiota;Bacteroides;Phocaeicola;prophages;
Type (COBISS): Doctoral dissertation
Study programme: 0
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Biotehniška fak.
Pages: 1 spletni vir (1 datoteka PDF (XI, 69 str., [39] str. pril.)
ID: 24676144