[MOLECULAR-GENETIC ANALYSIS OF MICROORGANISMS WITH INTRAEPITHELIAL INVASION ISOLATED FROM PATIENTS WITH COLORECTAL...

Area of Science:

• Microbiology
• Oncology
• Molecular Genetics

Background:

• Colorectal cancer (CRC) is a significant global health concern.
• The role of the gut microbiome in CRC pathogenesis is increasingly recognized.
• Specific bacterial species and their virulence factors may contribute to CRC development.

Purpose of the Study:

• To investigate the bacterial composition of rectal mucosa in CRC patients.
• To identify specific bacterial species and their pathogenic potential within the tumor microenvironment.
• To analyze genetic determinants of virulence in isolated bacteria.

Main Methods:

• Isolation and cultural-morphological analysis of facultative aerobic bacteria from rectal mucosa.
• Molecular-genetic identification using 16S rRNA gene sequencing.
• Analysis of genetic determinants for adhesive, hemolytic, and toxigenic activities.

Main Results:

• Adherent-invasive Escherichia coli (AIEC) and Klebsiella pneumonia were identified in the rectal mucosa of CRC patients.
• Some isolates possessed genetic determinants for toxins like colibactin and cytotoxic necrotic factor I, associated with potential carcinogenicity.
• No significant differences in toxigenicity factors were observed between bacteria from malignant and adjacent normal rectal epithelium.

Conclusions:

• Specific bacterial species, including AIEC and K. pneumonia, are present in the rectal mucosa of CRC patients.
• These bacteria harbor virulence factors, such as toxins, that may play a role in CRC.
• The presence and toxigenic potential of these bacteria in both tumor and normal tissue suggest a complex interaction in CRC development.