Biofilm-Forming oral Microorganisms in Dental Caries: Isolation, Identification, and Nanoemulsion Intervention

Introduction: Oral biofilm, or dental plaque, is a complex microbial community composed of bacteria, fungi, and other microbes that form extracellular polymeric substances (EPS), leading to dental caries, periodontal disorders, and other oral health problems. Biofilms are resistant to antimicrobial agents and host immune responses, necessitating alternative treatment strategies. Herbal extracts, probiotics, quorum-sensing inhibitors, and biomaterials are being explored as biofilm inhibitors. Objectives: This study aims to isolate and morphologically characterize microbial species from oral swabs and assess their biofilm-forming potential through a multidisciplinary approach involving colony morphology, VITEK® 2-based taxonomic identification, and biofilm evaluation using crystal violet and Congo red agar assays. Methods: Swabs from eight patients with dental caries and plaque were collected and used for laboratory analysis. Bacteria were isolated through serial dilution and cultured on nutrient and Mitis salivarius agar (MSA) media. Anaerobic and aerobic bacteria were identified using Gram’s staining and the VITEK® 2 automated system. The next step will involve nanoemulsion preparation to assess its antimicrobial and biofilm inhibition effects. Results: The study identified ten bacterial isolates from oral swabs, including Alloiococcus otitis, Enterococcus faecium, Klebsiella pneumoniae, Kocuria kristinae, Gemella bergeri, and Candida albicans, with distinct morphological features and confirmed taxonomy via the VITEK® 2 system. Among these, Enterococcus faecium (OD 1.32) and Alloiococcus otitis (OD 0.91) demonstrated significant biofilm-forming ability as confirmed by both crystal violet assay and Congo red agar assay, highlighting their potential role in oral biofilm development. Identified microorganisms included Alloiococcus otitis, Enterococcus faecium, Klebsiella pneumoniae, Kocuria kristinae, Gemella bergeri, and Candida albicans. Biofilm formation was assessed using Congo red and crystal violet assays, revealing biofilm production in Enterococcus faecalis and Alloiococcus otitis. Conclusions: This study concludes that among the six microbial species identified from oral swabs of eight patients with dental plaques, Alloiococcus otitis and Enterococcus faecalis demonstrated significant biofilm-forming ability as confirmed by crystal violet and Congo red agar assays, suggesting the need for future exploration into antibiofilm strategies