Pride and colleagues obtained saliva samples from four healthy subjects over the course of 17 months, sequencing CRISPR elements from multiple streptococcal bacteria, the predominant oral community members in many people. The team's analysis of CRISPR repeat and spacer sequences revealed that although there is a set of CRISPRs maintained within each subject over time, ranging from 7% to 22%, there was a remarkable amount of change observed even in short periods.
"Each time we sampled our human subjects, approximately one-third of the immune repertoire in the bacterial community was new," Pride explained, "which suggests that the development of resistance to viruses is occurring at least on a daily basis, if not more frequently."
Pride added that because the bacterial immune repertoire was traceable within the individuals over time, they should be able to track the system within each person and also track bacteria passed between subjects.
"Because these immune features can be used to track bacteria and their respective viruses in humans," Pride said, "it may open to door to more personalized oral health care, where lineages of microbes are traced as a part of routine health care for individuals."
|Contact: Peggy Calicchia|
Cold Spring Harbor Laboratory