Colorectal neoplasm in cases of Clostridium septicum and Streptococcus gallolyticus subsp. gallolyticus bacteraemia

Bacteremia with Clostridium septicum (CS) and Streptococcus gallolyticus subsp. gallolyticus (SGG) have both been associated with colorectal neoplasms (CRN) and colonoscopic examination is advised, however the differences and similarities in colorectal findings are not well known.

This is a multicenter, comparative study of patients with CS bacteremia [44 of 664 cases (6.6%) of Clostridium spp.] and SGG bacteremia [257 of 596 cases (44.2%) of S. bovis group], carried out in three hospitals from Spain. Clinical findings related to bacteremia and associated CRN were collected.

The main sources of infection were abdominal (77.7%) for CS bacteremia and endovascular (75%) for SGG bacteremia. CS bacteremia was more often associated with malignancies, (72.6% vs. 19.4%) and neutropenia (29.5% vs. 3.1%), and was more acute, with shock at presentation (63.6% vs. 3.9%) and higher 30-day mortality (47.7% vs. 9.7%) compared to SGG (P<0.05 for all). Both, patients with CS and SGG bacteremia often had concomitant CRN (43.1% vs. 49.8%) and most of them presented as occult CRN (73.7% vs. 91.4%; P=0.02). CS cases more often had invasive carcinomas (94.7% vs. 19.5%), location of CRN in the right colon (73.7% vs. 23.4%), larger tumor size (median 7 vs. 1.5cm), and a higher overall CRN related mortality rate (68.4% vs. 7.8%) compared to SGG cases (P<0.05 for all).

Both, CS and SGG bacteremia are associated with occult CRN. CS cases more often had advanced carcinomas than SGG cases, suggesting a distinct temporal association with CRN.