Antibiotic Susceptibility of Bacteria Strains in Patients with Fixed Orthodontic Treatment

Introduction: Fixed orthodontic appliances affect the microbial flora within the oral cavity. It enhances the accumulation and maturation of biofilm further leading to bacteremia in certain cases. Aim: To assess the antibiotic susceptibility of oral microorganisms in patients undergoing orthodontic fixed appliance therapy. Materials and Methods: Twenty-one young adults (11 females and 10 males) undergoing orthodontic treatment at Mahe Institute of Dental Sciences, Puducherry, India, participated in the study. Following a 21-day course of treatment, oral microbial samples were collected. The VITEK 2 AST system, different agar media, and Brain–Heart Infusion broth were used to identify the bacteria and determine their susceptibility to antibiotics. Results: Gram-positive bacteria showed high resistance to ampicillin (75%) and benzylpenicillin (91.7%), whereas they were sensitive to moxifloxacin (83.3%) and linezolid (91.7%). Gram-negative bacteria showed high sensitivity to gentamicin (100%) and tigecycline (88.9%) and 100% sensitivity to piperacillin and trimethoprim. Overall, the sensitivity of Gram-negative bacteria was significantly higher (81.2%) than that of Gram-positive bacteria (57.9%) ( P < 0.0001). Conclusion: Significant antibiotic resistance in Gram-positive bacteria, especially to penicillin and ampicillin, stresses the need for careful and regulated antibiotic use. However, Gram-negative bacteria showed high sensitivity to several antibiotics. Following culture tests for prescription and monitoring resistance pattern in oral microflora would go a long way in preserving the overall health of an Individual.