BACKGROUND- The association between S.mutans infective endocarditis and spondylodiscitis is extremely rare (only one case reported in the literature). Invasive dental procedures are known to increase the risk of infective endocarditis. ESC 2023 guidelines recommend antibiotic prophylaxis only in high-risk patients. However, these new guidelines do not consider the number of dental procedures performed in a short period of time. CASE PRESENTATION- We report the case of a patient affected by Streptococcus (S.) mutans infective endocarditis complicated by lumbar spondylodiscitis in consequence of the performance of multiple dental procedures without antibiotic prophylaxis; this may be the first case characterized by this association and requiring cardiac surgery. CONCLUSION- These infective events occurred despite a proper interpretation of current guidelines about the antibiotic prophylaxis but we believe that a case-by-case evaluation is useful in order to reduce the incidence of these complications. Specifically, it could be that the risk of developing endocarditis depends not only on the patient's risk category but also on the number of dental procedures performed in a short period of time.

Keywords: Case report, Endocarditis, spondylodiscitis, Streptococcus mutans, surgical aortic valve replacement, antibiotic prophylaxis.