Co-Occurrence of Anaerobic Bacteria in Colorectal Carcinomas

Resource type
Date created
2013
Authors/Contributors
Abstract
BackgroundNumerous cancers have been linked to microorganisms. Given that colorectal cancer is a leading cause of cancer deaths and the colon is continuously exposed to a high diversity of microbes, the relationship between gut mucosal microbiome and colorectal cancer needs to be explored. Metagenomic studies have shown an association between Fusobacterium species and colorectal carcinoma. Here, we have extended these studies with deeper sequencing of a much larger number (n = 130) of colorectal carcinoma and matched normal control tissues. We analyzed these data using co-occurrence networks in order to identify microbe-microbe and host-microbe associations specific to tumors.ResultsWe confirmed tumor over-representation of Fusobacterium species and observed significant co-occurrence within individual tumors of Fusobacterium, Leptotrichia and Campylobacter species. This polymicrobial signature was associated with over-expression of numerous host genes, including the gene encoding the pro-inflammatory chemokine Interleukin-8. The tumor-associated bacteria we have identified are all Gram-negative anaerobes, recognized previously as constituents of the oral microbiome, which are capable of causing infection. We isolated a novel strain of Campylobacter showae from a colorectal tumor specimen. This strain is substantially diverged from a previously sequenced oral Campylobacter showae isolate, carries potential virulence genes, and aggregates with a previously isolated tumor strain of Fusobacterium nucleatum.ConclusionsA polymicrobial signature of Gram-negative anaerobic bacteria is associated with colorectal carcinoma tissue.
Document
Published as
Microbiome 2013, 1:16 doi:10.1186/2049-2618-1-16
Publication title
Microbiome
Document title
Co-Occurrence of Anaerobic Bacteria in Colorectal Carcinomas
Date
2013
Volume
1
Issue
16
Publisher DOI
10.1186/2049-2618-1-16
Copyright statement
Copyright is held by the author(s).
Scholarly level
Peer reviewed?
Yes
Language
Attachment Size
2049-2618-1-16.pdf 2.49 MB