Biofilm Production Activity and Antibiotics Susceptibility of Streptococcus mutans Isolates from Patients with Dental Caries

Dental caries, a prevalent chronic infectious ailment, commences with the adherence of cariogenic bacteria to the teeth, particularly Streptococcus mutans. These microorganisms utilize sugars to produce acid, resulting in the gradual demineralization of the dental structure. Streptococcus mutans a gram positive bacterium is found to play the most significant role in the dental caries in terms of being the earliest colonizer in the formation of caries. The current research focuses on the isolation and identification of the Streptococcus mutans pathogen in individuals affected by dental caries. The isolated strains were cultured on specific media, with one hundred samples of dental caries obtained from human teeth. Among these samples, fifty were identified as positive bacterial isolates utilizing MS-agar (Mitist Salivares agar), with ten isolates categorized under the group Streptococci and twenty isolates identified as S. mutans. Identification of bacterial isolates was carried out based on morphological and cultural characteristics, biochemical tests, and VITEK-II. Additionally, an antibiogram assay was conducted to assess the susceptibility and resistance of the pathogen to various drugs. The findings revealed that all locally isolated S. mutans strains displayed 100% resistance to Cefepime, while showing different levels of resistance and susceptibility to other antibiotics such as Doxycycline, Amoxicillin-clavulanic acid, Trimethoprim-sulfamethoxazole, Vancomycin, Tetracycline, Ampicillin, and Meropenem. In this study, ELISA was employed to differentiate between Streptococcus. mutans isolates that produced biofilms and those that did not by utilizing the optical density at 630 nm. Bacterial biofilms contribute to chronic diseases that pose challenges in treatment. Twenty distinct isolates were evaluated for their biofilm-forming capabilities, with 9 (45%) identified as strong biofilm producers, 7 (35%) classified as moderate biofilm producers, and 4 (20%) categorized as weak biofilm producers