Identification and Antibiogram Profile of Streptococcus mutans and Streptococcus sobrinus from Dental Caries Subjects

Dental caries is one of the oldest disease in the world and its causative agent is mutans streptococci (MS). Among MS, Streptococcus mutans and Streptococcus sobrinus are implicated in caries active subjects. The objective of this study was to identify and determine the antibiogram profile of S. mutans and S. sobrinus isolates. The dental plaque samples were collected from caries active subjects (aged 35-44 years) and later identified by 16S rDNA sequencing. Out of 65 clinical isolates 36 (55.38%) were S. mutans and 5 (7.69%) were S. sobrinus. Antibiogram profiling was performed to determine the susceptibility of 6 β-Lactam antibiotics (penicillin, ampicillin, cefotaxime, cephalothin, cefazolin and methicillin) and 2 non β-Lactam antibiotics (erythromycin and chloramphenicol) by disc diffusion method. All S. mutans and S. sobrinus isolates were susceptible to the antibiotics employed in this study. Penicillin and ampicillin were the most effective antibiotics against S. mutans and S. sobrinus isolates and no resistance found. The study concludes that all the isolates were susceptible to the antibiotics, and suggests that taking extra precaution while prescribing antibiotics will maintain the bacteria with less resistance. It also recommends to use an alternative prevention, such as a plant extract to avoid upcoming resistance.