https://phys.org/news/2018-07-sequence-rare-bacteria-rampant-tooth.html

According to Jensen, S. sobrinus is difficult to work with in the lab and it is not present in all people, so researchers have instead focused their efforts over the years on understanding the more stable and prevalent S. mutans, which was sequenced in 2002.

"Although it is rare, S. sobrinus produces acid more quickly and is associated with the poorest clinical outcomes, especially among children," noted Jensen, a researcher at the Carl R. Woese Institute for Genomic Biology on campus. "If S. sobrinus is present along with S. mutans, you're at risk for rampant tooth decay, which means there's some level of communication or synergy between the two that we don't understand yet."