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

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.

Hinchey I and II diverticular abscesses: long-term outcome of conservative treatment.

BACKGROUND: The management of diverticular disease and its complications are an increasing burden to the health system. The natural history of conservatively managed diverticular abscesses (Hinchey I and II) is poorly described and it remains open to debate whether subsequent sigmoid resection is indicated after conservative management. This observational study compares outcomes of patients treated with conservative management (antibiotics +/- percutaneous drainage) and surgery. METHODS: All patients admitted at Christchurch Hospital with diverticulitis between 1 January 1998 and 31 December 2009 were recorded in a database. A retrospective analysis of patients with an abscess due to complicated diverticulitis was undertaken. Initial management, recurrence and subsequent surgery were recorded. The patients were followed until 1 January 2014. RESULTS: Of 1044 patients with diverticulitis, 107 with diverticular abscess were included in this analysis. The median age was 66 ± 16 and 60 were male. All patients had sigmoid diverticulitis and were diagnosed with a computed tomography. The median abscess size was 4.2 ± 2.1 cm. During median follow-up of 110 months, the overall recurrence rate was 20% (21/107). Recurrence varied according to initial treatment; namely antibiotics (30%), percutaneous drainage plus antibiotics (27%) and surgery (5%) (P = 0.004). The median time to recurrence was 4 ± 11.7 months, and most recurrences were treated conservatively; four patients underwent delayed surgery. CONCLUSION: Recurrence after diverticular abscess is higher after initial conservative treatment (antibiotics +/- percutaneous drainage) compared with surgery, however, patients with recurrent disease can be treated conservatively with similar good outcomes and few patients required further surgery.