16S rRNA-based analysis of bacterial diversity in the microbial flora of the goose intestinal tract

The microflora in the gastrointestinal tract of poultry influences digestion, health, and wellbeing. Analysis of poultry gut microflora has been done mainly by culture-based methods. Studies using these techniques have been useful for identification and analysis of specific groups of bacteria, however, the use of enrichment medium precludes even relative quantitation of bacterial species. Recent advances in molecular techniques make it possible to identify different bacterial populations in poultry gastrointestinal tract. In this study, the intestinal microbiota was examined using 16S rRNA targeted probes from bacterial DNA isolated from five intestinal sections. DNA from microbial flora of five intestinal sections (duodenum, jejunum, ileum, caecum, colon) of six geese was extracted by lysozyme-SDS-phenol/chloroform and freeze thawing combined method. The predominant bacterial community structure was analysed by Polymerase Chain Reaction (PCR) amplification of the DNA followed by Denaturing Gradient Gel Electrophoresis (DGGE). The results showed that there were common bands in the five tract segments analysed, but also many differential bands. Phylogenetic and similarity analyses of the sequences of the cloned fragments from DGGE revealed that the similarity of 26 clones was over 97%, others were between 94~96%, and 19 clones of all were similar to sequences of uncultured bacteria.