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Gastrointestinal microbiology - part 3

Chiến lược này cũng được sử dụng để đánh giá sự đa dạng phân bifidobacterial của 10 trẻ sơ sinh. Một mẫu đã không có sản phẩm PCR, 8 / 10 Bif có. bifidum (một trong số đó nuôi dưỡng một amplicon thứ hai không xác định) và mẫu cuối cùng bao gồm Bif. infantis, Bif. longum và amplicon một không xác định. | 66 McCartney and Gibson of the remaining three samples contained Bif. longum the final sample contained Bif. bifidum. This strategy was also employed to assess the fecal bifidobacterial diversity of 10 babies. One sample gave no PCR product 8 10 contained Bif. bifidum one of which harbored a second unidentified amplicon and the final sample comprised Bif. infantis Bif. longum and an unidentified amplicon. Comparison of bifidobacterial enumerations obtained from plate counts and bifidobacterial-specific real-time PCR with either transaldolase gene primers or 16S rRNA primers has been performed 69 . Good correlation was seen between all three enumeration methods when healthy adult samples were used n 7 . Correlation of bifidobacterial levels in infant samples n 10 was better between cultivation work and 16S rRNA gene real-time PCR than between cultivation work and transaldolase gene real-time PCR. Under-representation of the Bif. bifidum component of samples during transaldolase gene real-time PCR was largely responsible for this discrepancy. Probing Strategies As well as affording design of PCR primers for specific bacterial populations the improved 16S rRNA gene sequence information has greatly enhanced the development of probing strategies for gut micro-organisms. Two probing strategies have generally been employed namely dot-blot hybridization and fluorescent in situ hybridization FISH . The nature of the 16S rRNA gene of bacteria also enables development of oligonucleotide probes targeting different taxonomic levels i.e. domain level Bact 338 group level e.g. Chis 150 genus level e.g. Bif 164 or species level e.g. Bdis 656 57 70 . The last 5 years have seen enormous development and application of these strategies in gut microbiology 71-76 . A longitudinal study was performed with nine healthy human volunteers five males four females monitoring the fecal microbiota using FISH 72 . The results demonstrated that 90-100 of 40 6-diamidino-2-phenylindol .