June 3, 2008
For people with a prosthetic joint or a life-threatening heart condition, blood-borne infections are potentially devastating to their health and well being. That’s why before visiting a dentist or even brushing their teeth, many have been advised to use antibiotic mouth rinses to kill bacteria and prevent oral pathogens from passing into the bloodstream (called bacteremia) and possibly contributing to an infection. But little is really known about which microbes are most likely during dental care to enter the bloodstream. As published online recently in the Journal of Clinical Microbiology, a team of NIDCR-supported researchers offer a glimpse. The scientists collected blood samples from 290 healthy adults following either two minutes of tooth brushing; a tooth extraction with the recommended accompanying dose of oral amoxicillin; or a tooth extraction with a placebo pill. According to the scientists, 151 people developed bacteremia. Using molecular techniques, the scientists identified 98 different bacterial species in the blood. Included among the bacteria were 19 novel species of Prevotella, Fusobacterium, Streptococcus, Actinomyces, Capnocytophaga, Selenomonas, and Veilonella. “Antibiotic prophylaxis reduced the incidence of bacteremia from tooth extraction,” the researchers concluded. “It also resulted in bacteremia with fewer bacterial species, which were cleared from the blood in a shorter time (i.e., mostly within 20 minutes). Although antibiotic prophylaxis reduced the bacteremia of several species of streptococci, as expected, it does not seem to affect species of proteobacteria (e.g., E. corrodens) and Prevotella.”