Temporal changes in enterococcal species in the human intestine, and persistence of Enterococcus faecium SF68 following its administration to healthy volunteers
Abstract number: 1134_01_356
Vankerckhoven V., Lammens C., Goossens H.
To investigate the temporal changes in enterococcal species in the human intestine, and the persistence of the probiotic strain, Enterococcus faecium SF68, a human volunteer study was conducted.
A total of 13 healthy volunteers were enrolled in the study. Seven subjects received 2 capsules of Entercoccus faecium SF68 (108 CFU/caps.) thrice daily for 5 days, while 6 subjects formed the control group. Faecal samples from all subjects were collected before E. faecium SF68 administration (day 0) and on days 4, 10, 20, weeks 5, 7, 9, 11, and months 6, 8, 12. Pre-probiotic administration, stools were screened for enterococcal species and their clonality for all volunteers and further on, only for the control group. Faecal samples were plated on Enterococcal agar and after 48 h of incubation, 10 esculin hydrolysing colonies were followed further. PYR was used for genus identification, while species identification was studied by RAPD-PCR using primer D11344, and in case of inconclusive results, by SDS-PAGE of whole-cell proteins. Clonality was investigated by RAPD-PCR using primers D11344 and D14307, and in case of discordant results between the 2 primer sets, by PFGE using SmaI.
From 127 enterococci isolated on day 0, a total of 5 different species were identified: E. faecium (47%), E. faecalis (39%), E. durans (11%), E. hirae (2%) and E. gallinarum (<1%). From day 4 to month 12, 744 enterococci were isolated from the control group and identified as: E. faecium (59%), E. faecalis (26%), E. durans (7%), E. hirae (3%); other species (E. casseliflavus, E. avium, E. mundtii) were <2%. Distribution of clonal types, especially in E. faecium and E. faecalis, varied among the control group. During the study period clonal types in E. faecalis varied from 1 to 6 and in E. faecium between 8 to 14 types, which was on an average twice the number of types/isolation day compared to E. faecalis. Post-administration, E. faecium SF68 was detected in all 7 subjects on day 4. At week 9, only a single volunteer showed the presence of E. faecium SF68 and at week 11 none of the volunteers were found to carry the probiotic strain.
The composition of the commensal enterococcal faecal flora was found to fluctuate over the study period of 1 year with E. faecium and E. faecalis being the predominate species. This is the first study showing the persistence of colonisation by a probiotic strain in the intestine for such a prolonged period.
|Session name:||XXIst ISTH Congress|
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