Journal article
Community analysis of bacteria colonizing intestinal tissue of neonates with necrotizing enterocolitis
Statens Serum Institut1
Copenhagen University Hospital Herlev and Gentofte2
Bacteriology & Pathology, Division of Veterinary Diagnostics and Research, National Veterinary Institute, Technical University of Denmark3
Division of Veterinary Diagnostics and Research, National Veterinary Institute, Technical University of Denmark4
National Veterinary Institute, Technical University of Denmark5
University of Copenhagen6
Microbial Ecology, Division of Veterinary Diagnostics and Research, National Veterinary Institute, Technical University of Denmark7
BACKGROUND: Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency in newborn neonates. Bacteria are believed to be important in the pathogenesis of NEC but bacterial characterization has only been done on human faecal samples and experimental animal studies. The aim of this study was to investigate the microbial composition and the relative number of bacteria in inflamed intestinal tissue surgically removed from neonates diagnosed with NEC (n = 24).
The bacterial populations in the specimens were characterized by laser capture microdissection and subsequent sequencing combined with fluorescent in situ hybridization (FISH), using bacterial rRNA-targeting oligonucleotide probes. RESULTS: Bacteria were detected in 22 of the 24 specimens, 71% had moderate to high densities of bacteria.
The phyla detected by 16S rRNA gene sequencing were: Proteobacteria (49.0%), Firmicutes (30.4%), Actinobacteria (17.1%) and Bacteroidetes (3.6%). A major detected class of the phylum Proteobacteria belonged to δ-proteobacteria. Surprisingly, Clostridium species were only detected in 4 of the specimens by FISH, but two of these specimens exhibited histological pneumatosis intestinalis and both specimens had a moderate to a high density of C. butyricum and C. parputrificum detected by using species specific FISH probes.
A 16S rRNA gene sequence tag similar to Ralstonia species was detected in most of the neonatal tissues and members of this genus have been reported to be opportunistic pathogens but their role in NEC has still to be clarified. CONCLUSION: In this study, in situ identification and community analysis of bacteria found in tissue specimens from neonates with NEC, were analysed for the first time.
Although a large variability of bacteria was found in most of the analyzed specimens, no single or combination of known potential pathogenic bacteria species was dominating the samples suggestive NEC as non-infectious syndrome. However there was a significant correlation between the presence of C. butyricum & C. parputrificum and histological pneumatosis intestinalis.
Finally this study emphasizes the possibility to examine the microbial composition directly on excised human tissues to avoid biases from faecal samples or culturing.
Language: | English |
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Publisher: | BioMed Central |
Year: | 2011 |
Pages: | 73-73 |
ISSN: | 14712180 |
Types: | Journal article |
DOI: | 10.1186/1471-2180-11-73 |
ORCIDs: | 0000-0003-0261-616X , Jensen, Tim Kåre and Boye, Mette |
<it>Ralstornia</it> Bacteria Biodiversity DNA, Bacterial DNA, Ribosomal Enterocolitis, Necrotizing FISH Female Gastrointestinal Tract Humans In Situ Hybridization, Fluorescence Infant, Newborn Male Microbiology QR1-502 RNA, Ribosomal, 16S Ralstornia Sequence Analysis, DNA laser capture microdissection microbiota necrotizing enterocolitis pneumatosis intestinalis