Streptococcus bovis bacteraemia revisited: clinical and microbiological correlates in a contemporary series of 59 patients.

OBJECTIVE: To characterise the clinical features, associations and outcome in a contemporary series of patients with Streptococcus bovis bacteraemia (SBB).
METHODS: Retrospective analysis of all episodes of SBB at the University Hospital 12 de Octubre (Madrid, Spain) between January 1997 and November 2008 was performed. Patient data were reviewed, focusing on clinical and microbiological associations with the different biotypes of S. bovis.
RESULTS: Fifty-nine episodes of SBB were documented in 59 adult patients (30 males; mean age: 70.9 ± 15.0 years). Chronic liver disease was identified in 20 patients (33.9%). Sixteen patients (27.1%) presented infective endocarditis (IE) and 14 (23.7%) had a biliary source of bacteraemia. Thirty-three patients (55.9%) underwent colonic evaluation, adenomatous polyps being the most common finding (21 patients). Malignancy was diagnosed following SBB in 9 cases, including 6 patients with colorectal carcinoma (18.2% of those who underwent colonic evaluation). Of 22 isolates biotyped, 12 were S. bovis biotype I and 10 were S. bovis biotype II. IE was more frequent among patients with S. bovis biotype I (P =0.010), whereas bacteraemia due to biotype II species was more likely to be of biliary origin (P=0.078).
CONCLUSIONS: S. bovis biotyping identifies some clinically relevant associations.