Detection of gbpA and gbpB in Streptococcus mutans Isolated from Patients with Oral Potentially Malignant Disorders: A Pilot Study

Abstract

Introduction: Glucan-binding proteins (gbps) in Streptococcus mutans (S. mutans) are considered vital virulence factors contributing to plaque formation and caries progression. These proteins also aid in maintaining biofilm formation on the tooth surface and further colonisation of S. mutans. Aim: To phenotypically characterise S. mutans from clinical samples of patients with Oral Potentially Malignant Disorder (OPMD), healthy individuals with and without caries, and to assess the frequency of the gbpA and gbpB genes among the groups. Materials and Methods: This pilot study was conducted for a period of two months from May to June 2023 in the Department of Microbiology at Saveetha Dental College and Hospitals, Chennai, Tamil Nadu, India. Saliva samples (N=60) were collected from 20 patients in each of the three different groups: Group 1 included OPMD cases, Group 2 comprised healthy individuals with caries, and Group 3 consisted of healthy individuals without caries (control). Demographic data including age, gender, geographical location, and any previous history of clinical illness were recorded. The samples were promptly transferred to the microbiology lab and cultured on sterile Mutans Sanguis (MS) agar, followed by incubation at 37°C for 48 hours. S. mutans were phenotypically characterised, and the frequency of the gbpA and gbpB genes was assessed using Polymerase Chain Reaction (PCR). Results: The prevalence of S. mutans among the study population was found to be 9 (45%) in Group 1, 8 (40%) in Group 2, and 3 (15%) in Group 3. The study findings revealed the presence of gbps in S. mutans isolated from OPMD cases, patients with caries, and non-cariogenic healthy patients, with the frequency of gbpA as 8 (88%), 7 (87.5%), and 1 (33.3%), and gbpB as 9 (100%), 5 (62.5%), and 1 (33.3%), respectively. Conclusion: The frequency of gbpA and gbpB from the clinical strains of S. mutans associated with caries and OPMD cases was observed in the present study. Periodic surveillance of such virulent determinants would aid in a theragnostic approach to alleviate the complications caused by S. mutans in OPMD cases.

Keywords

• caries
• pathogenesis
• oral health
• virulence