From the Guidelines
Colibactin is primarily produced by certain strains of Escherichia coli (E. coli) that carry a genomic island called pks (polyketide synthase), referred to as pks+ E. coli. These specific E. coli strains are the main producers of colibactin, a genotoxic compound that can damage DNA in host cells, potentially contributing to colorectal cancer development through the induction of DNA double-strand breaks and chromosomal aberrations 1. While E. coli is the main producer, some other Enterobacteriaceae family members like certain Klebsiella pneumoniae strains can also produce colibactin if they possess the pks island.
The presence of colibactin-producing bacteria in the intestinal microbiota may represent a risk factor for colorectal cancer development, though this relationship is still being actively researched. Some studies have reported microbial composition and ecology changes in patients with CRC, and functional studies in animal models have indicated the roles of several bacteria in driving colorectal carcinogenesis, such as Fusobacterium nucleatum and certain strains of Escherichia coli and Bacteroides fragilis 1.
Key points to consider:
- Colibactin is a genotoxic compound that can damage DNA in host cells
- pks+ E. coli strains are the main producers of colibactin
- The presence of colibactin-producing bacteria in the intestinal microbiota may represent a risk factor for colorectal cancer development
- Other Enterobacteriaceae family members like certain Klebsiella pneumoniae strains can also produce colibactin if they possess the pks island
- Microbial composition and ecology changes in patients with CRC have been reported, and functional studies in animal models have indicated the roles of several bacteria in driving colorectal carcinogenesis 1.
From the Research
Bacteria Producing Colibactin
- Escherichia coli (E. coli) strains, specifically those harboring polyketide synthase (pks) genes, are known to produce colibactin 2, 3, 4, 5, 6
- Klebsiella pneumoniae (K. pneumoniae) has also been found to produce colibactin, with a pks gene cluster sharing 100% sequence identity with E. coli, suggesting conserved function and regulation 3
Characteristics of Colibactin-Producing Bacteria
- Colibactin is a complex secondary metabolite and a potent genotoxic metabolite that causes DNA damage 2, 5, 6
- The presence of colibactin-producing bacteria has been correlated with the frequency and severity of colorectal cancer in humans 2, 3, 4
- The biosynthetic machinery for colibactin production is encoded by 19 genes within the pks pathogenicity island in E. coli 5