BioProject

Streptococcus bovis group (previously group D streptococci) consists of seven distinct species and subspecies. More...

Streptococcus bovis group (previously group D streptococci) consists of seven distinct species and subspecies. Definitive identification within the group is important as certain organisms have been associated with gastrointestinal carcinoma, bacteremia, infective endocarditis, meningitis, and biliary tract disease and carcinoma, among others. Definitive identification, however, remains elusive due to limitations and inconsistencies across commonly used identification platforms in the United States. Here, we compared the performance of standard biochemical (TREK GPID, VITEK2 GPID), sequencing (16S rDNA, sodA) databases (NCBI, RDP, CDC MicrobeNet), and MALDI-TOF MS platforms (VITEK MS, Bruker BioTyper MS) using an isolate set representing all seven Type strains within the S. bovis group. Further clinical evaluation was conducted using 65 clinical isolates from three geographically distinct US institutions. Despite the evaluation of contemporary methods, no single platform was able to definitively identify all Type strains within the S. bovis group. VITEK MS (85.7%, 7/8) provided the most accurate definitive identifications, followed by sodA sequencing (75%, 6/8). VITEK2 and Bruker BioTyper RUO platforms performed next best (62.5%, 5/8). All remaining platforms failed to adequately differentiate Type strains within the S. bovis group (range 0-37.5%). Laboratorians and clinicians should be aware of the identification limitations of routine testing algorithms and incorporate reflex testing to higher accuracy platforms such as VITEK MS and/or sodA sequencing when appropriate. Future improvements in identification platforms may reveal new clinical and epidemiological trends for members of the S. bovis group. Less...