Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

Additional file 4: of The presence of bacteria varies between colorectal adenocarcinomas, precursor lesions and non-malignant tissue

16S rRNA gene sequences. FASTA file containing the DNA sequences generated using 16S rRNA gene sequencing. (FA 243 kb

Additional file 2: of The presence of bacteria varies between colorectal adenocarcinomas, precursor lesions and non-malignant tissue

Tissue samples used for 16S rRNA gene sequencing. Quantification cycles obtained using qPCR and clinical information for each clinical sample investigated using Illumina sequencing of the V4 region of the 16S rRNA gene. (XLSX 31 kb

Additional file 5: of The presence of bacteria varies between colorectal adenocarcinomas, precursor lesions and non-malignant tissue

16S rRNA gene sequencing OTUtable. OTU table documenting numbers of different OTUs generated during the 16S rRNA gene sequencing. (TXT 163 kb

Additional file 3: of The presence of bacteria varies between colorectal adenocarcinomas, precursor lesions and non-malignant tissue

16S rRNA gene sequencing metadata. Information describing the samples included for bioinformatics analysis of the 16S rRNA gene sequencing data. (XLSX 11 kb

The presence of bacteria varies between colorectal adenocarcinomas, precursor lesions and non-malignant tissue

Abstract Background A causal association has been suggested between certain bacteria and colorectal cancer (CRC). Only a few studies have, however, investigated the presence of these bacteria directly in colon tissue with conflicting results. It is thus uncertain which role they may have in prognosis and carcinogenesis of CRC. Methods Formalin-fixed and paraffin-embedded (FFPE) colorectal tissue samples from patients diagnosed with colorectal cancer (CRC)(tumor and paired normal tissue, n = 99), adenomas (n = 96), or diverticular disease (n = 104) were tested for the presence and bacterial load of Streptococcus gallolyticus (S. gallolyticus), Fusobacterium nucleatum (F. nucleatum), and Bacteroides fragilis (B. fragilis) using quantitative PCR. A subsequent broader search was conducted on a subset of samples using 16S ribosomal RNA gene sequencing. Finally, to evaluate the prognostic value, the bacterial status was compared to patient outcome. Results S. gallolyticus was not detected by qPCR in any of the investigated tissue samples and F. nucleatum and B. fragilis were found to be equally distributed in tumors, paired normal tissue, and diverticula, but significantly less present in adenomas compared to both tumors and diverticula. Neither, F. nucleatum nor B. fragilis status affected the five-year prognosis of the patients. The 16S rRNA gene sequencing data revealed that tumors were associated with the Prevotella genus while conversely adenomas and diverticula were associated with Acinetobacter genus. Conclusion These findings do not support a role of F. nucleatum or B. fragilis during colorectal beginning, while S. gallolyticus was not implicated in the colorectal tissue of a Danish population. A potential role of the bacterial genera Prevotella and Acinetobacter was indicated, and requires further investigations

Additional file 1: of The presence of bacteria varies between colorectal adenocarcinomas, precursor lesions and non-malignant tissue

qPCR results. Quantification cycles obtained using qPCR and clinical information for each clinical sample, investigated in this study. (XLSX 103 kb

Additional file 2: of The presence of bacteria varies between colorectal adenocarcinomas, precursor lesions and non-malignant tissue

Tissue samples used for 16S rRNA gene sequencing. Quantification cycles obtained using qPCR and clinical information for each clinical sample investigated using Illumina sequencing of the V4 region of the 16S rRNA gene. (XLSX 31 kb

Additional file 3: of The presence of bacteria varies between colorectal adenocarcinomas, precursor lesions and non-malignant tissue

16S rRNA gene sequencing metadata. Information describing the samples included for bioinformatics analysis of the 16S rRNA gene sequencing data. (XLSX 11 kb

The presence of bacteria varies between colorectal adenocarcinomas, precursor lesions and non-malignant tissue

Abstract Background A causal association has been suggested between certain bacteria and colorectal cancer (CRC). Only a few studies have, however, investigated the presence of these bacteria directly in colon tissue with conflicting results. It is thus uncertain which role they may have in prognosis and carcinogenesis of CRC. Methods Formalin-fixed and paraffin-embedded (FFPE) colorectal tissue samples from patients diagnosed with colorectal cancer (CRC)(tumor and paired normal tissue, n = 99), adenomas (n = 96), or diverticular disease (n = 104) were tested for the presence and bacterial load of Streptococcus gallolyticus (S. gallolyticus), Fusobacterium nucleatum (F. nucleatum), and Bacteroides fragilis (B. fragilis) using quantitative PCR. A subsequent broader search was conducted on a subset of samples using 16S ribosomal RNA gene sequencing. Finally, to evaluate the prognostic value, the bacterial status was compared to patient outcome. Results S. gallolyticus was not detected by qPCR in any of the investigated tissue samples and F. nucleatum and B. fragilis were found to be equally distributed in tumors, paired normal tissue, and diverticula, but significantly less present in adenomas compared to both tumors and diverticula. Neither, F. nucleatum nor B. fragilis status affected the five-year prognosis of the patients. The 16S rRNA gene sequencing data revealed that tumors were associated with the Prevotella genus while conversely adenomas and diverticula were associated with Acinetobacter genus. Conclusion These findings do not support a role of F. nucleatum or B. fragilis during colorectal beginning, while S. gallolyticus was not implicated in the colorectal tissue of a Danish population. A potential role of the bacterial genera Prevotella and Acinetobacter was indicated, and requires further investigations