Bacteremia with the bovis group streptococci: species identification and association with infective endocarditis and with gastrointestinal disease

Abstract

DNA sequencing of the intergenic spacer (ITS) region was used to identify 53 blood culture isolates that had previously been designated to the bovis group streptococci and clinical data was collected retrospectively from patients' records using a standardized protocol. ITS sequencing identified 19 (35.8%) isolates as Streptococcus gallolyticus subsp. gallolyticus, 12 (22.6%) as S. gallolyticus subsp. pasteurianus, two (3.8%) as S. gallolyticus subsp. macedonicus, seven (13.2%) as S. infantarius subsp. infantarius, 12 (22.6%) as S. lutetiensis and one (1.9%) as S. equinus. The association of S. gallolyticus subsp. gallolyticus with colorectal neoplasia and with infective endocarditis and the association between S. gallolyticus subsp. pasteurianus and pancreatic cancer were found to be clinically important. Also, a very high 1-year mortality rate with S. lutetiensis (66.7%) and S. gallolyticus subsp. pasteurianus (58.7%) bacteremia calls for intensive investigation for underlying disease focusing on the pancreas and the hepatobiliary system.

Keywords: Bacteremia; Bovis group streptococci; Colorectal cancer; Infective endocarditis; Sequencing of the intergenic spacer region.