Current Trends in the Antibiotic Sensitivity Profile and their Comparison with Chlorhexidine, Nisin, and their Combination on Oral Bacterial Isolates Using the Kirby-Bauer Method
Keywords:
Antibiotics, Disk Diffusion, Antimicrobial Tests, Bacteria, Oral, SensitivityAbstract
OBJECTIVE: To evaluate the sensitivity profile of antibiotics on different oral bacterial species using the Kirby-Bauer Method and to compare them with Nisin and Chlorhexidine and their combination.
METHODOLOGY: A prospective cross-sectional study, conducted at the Microbiology laboratory of Jinnah University for Women, from September 2023 to 2024. Supragingival plaque samples were collected from residents of Karachi, regardless of gender, who were at least eighteen years old and had a Loe and Silness plaque index of 1 to 3. Individuals on antibiotic therapy within 12 weeks of sampling, with severe systemic illnesses, persistent systemic infections, or known communicable diseases were excluded. Sensitivity profiling of five different antibiotic classes was assessed by using the Kirby-Bauer Method and compared with the zone of inhibition of a 10% solution of Nisin, 0.2% chlorhexidine, and their combination. Data were analyzed using SPSS version 25.0.
RESULTS: Clarithromycin showed the highest mean zone of inhibition, while Optochin showed no zone. Wilcoxon signed-rank tests revealed a statistically significant difference for Clarithromycin. Nisin and chlorhexidine showed statistically significant results of zone of inhibition with multiple antibiotics, while the combination showed substantial results only with Clarithromycin.
CONCLUSION: Clinically isolated oral bacterial species exhibited a wide range of antibiotic sensitivities, reflecting variations in microbial susceptibility and antimicrobial processes. Comparison of Nisin and chlorhexidine with commercially available antibiotics showed varying degrees of statistical significance. Nisin may be a helpful biocompatible alternative for the inhibition of bacterial growth in oral Supragingival plaque biofilms.
References
1. Neal TW, Schlieve T. Complications of severe odontogenic infections: a review. Biology. 2022 Dec 8;11(12):1784.
2. Kashif M, Kazmi M, Tanwir F, Akbar S, Mujtaba F, Gul S. Isolation, Identification and Phenotypic Analysis of the Oral Bacterial Species from Supragingival Dental Plaque and Their Association with Different Factors. Bangladesh J Med Sci. 2025; 24(4): 1153–1166. https://doi.org/10.3329/bjms.v24i4.84687.
3. Khan RT, Sharma V, Khan SS, Rasool S. Prevention and potential remedies for antibiotic resistance: current research and future prospects. Front Microbiol. 2024 Oct 3; 15: 1455759.
4. Abdullah FM, Hatim QY, Oraibi AI, Alsafar TH, Alsandook TA, Lutfi W et al. Antimicrobial management of dental infections: Updated review. Medicine. 2024 Jul 5; 103(27): e38630.
5. Kashif M, Ashar A. Important microbes in dentistry. 2024. Microbes Med Importance. IIP Series. 515-45.
6. Thompson W, Williams D, Pulcini C, Sanderson S, Calfon P, Verma M. Tackling antibiotic resistance: why dentistry matters. Int Dent J. 2021 Feb 10; 71(6): 450.
7. Humphries R, Bobenchik AM, Hindler JA, Schuetz AN. Overview of changes to the Clinical and Laboratory Standards Institute performance standards for antimicrobial susceptibility testing, M100. J Clin Microbiol. 2021 Nov 18; 59(12): 10-128.
8. Hossain TJ. Methods for screening and evaluation of antimicrobial activity: A review of protocols, advantages, and limitations. European journal of microbiology & immunology. 2024; 14(2): 97–115. https://doi.org/10.1556/1886.2024.00035.
9. Löe H. The gingival index, the plaque index and the retention index systems. J Periodontology. 1967 Nov; 38(6): 610-6.
10. Zaheer J, Khan MN, Rahman AU, Shahzad MA, Yaasir Z, Lateef M et al. Identification and Epidemiological Analysis of Antibiotic-Resistant Bacteria in the Oral Microbiome of the Population in Pakistan. Cureus. 2024 Oct 1; 16(10): e70666. doi: 10.7759/cureus.70666.
11. Zaheer J, Khan MN, Rahman AU, Ishfaq M, Shahzad MA, Lateef M et al. Characterization of Antibiotic Resistance Profiles in the Oral Microbiota of the Pakistani Population. Cureus. 2024; 16(10): e72617. https://doi.org/10.7759/cureus.72617.
12. Bayani M, Raisolvaezin K, Almasi-Hashiani A, Mirhoseini SH. Bacterial biofilm prevalence in dental unit waterlines: a systematic review and meta-analysis. BMC Oral Health. 2023 Mar 18; 23(1): 158.
13. Kashif M, Kazmi M. Probiotics, A New Frontier in Oral Health: Unraveling the Efficacy of Probiotic Metabolites vs Chlorhexidine on Streptococcus mutans in Dental Plaque. J Pak Med Assoc. 2024 Mar 1; 74(3): 430-1.
14. Radaic A, de Jesus VC, Kapila YL. The oralome and its dysbiosis: New insights into oral microbiome-host interactions. Comput Struct Biotech J. 2022; 20: 141-152.
15. Chaiyasut C, Sivamaruthi BS, Sirilun S. Evaluation of Nisin-based products in dental applications: A review of in vitro and in vivo studies. J Oral Biosci. 2022; 64(1): 45-52.
16. Funk A, Jia Q, Janke L, Crawford A, Iverson A, Rosch J et al. Isolation and characterization of a novel alpha-hemolytic Streptococcus spp. from the oral cavity and blood of septicemic periparturient immunodeficient mice. Compar Med. 2023 Oct; 73(5): 346.
17. Alves DR. Antimicrobial activity of macrolides against oral pathogens: current perspectives. J Oral Microbiol. 2023; 15(1): 2184567.
18. Chen L. Penicillin resistance in oral streptococci: molecular mechanisms and clinical implications. Front Cell Infect Microbiol. 2022; 12: 949312.
19. Teymouri M, Mollazadeh S, Oroojalian F, Amani A, Arezumand R, Shakeri F. Liposomes used in the delivery of various antimicrobials to biofilm-producing infections: a systematic review. Nanomed J. 2025 Apr 1; 12(2).
20. Nayeem A, Suresh AS, Vellapandian C, Singh S, Elossaily GM, Prajapati BG. Comprehensive Insights into Cephalosporins: Spectrum, Generations, and Clinical Applications. Current Drug Therapy. 2024 Dec 17. https://doi.org/10.2174/0115748855339119241204071146.
21. Zhang X, Tan L, Ouyang P, Ma H, Peng J, Shi T et al. Analysis of distribution and antibiotic resistance of Gram-positive bacteria isolated from a tertiary-care hospital in southern China: an 8-year retrospective study. Front Microbiol. 2023 Sep 28; 14: 1220363.
22. Khan M, Samant PS, Chauhan R, Khan R, Siddiqui S, Sachan S. Comparative Evaluation of Effectiveness of Nisin, Amoxicillin/Clavulanic Acid (Augmentin) and Chlorhexidine on E. faecalis as an Intracanal Irrigant: An In-vitro Study. J Pharm Bioallied Sci. 2023 Jul; 15(Suppl 2): S1317–S1320.
23. Shivaee A, Kazemi F, Navidifar T. Global trends in macrolide and lincosamide resistance in Streptococcus species: a comprehensive systematic review and meta-analysis. BMC Infect Dis. 2025; 25: 1577. https://doi.org/10.1186/s12879-025-11884-5.
24. Amin AN, Dellinger EP, Harnett G, Kraft BD, LaPlante KL, LoVecchio F et al. It's about the patients: Practical antibiotic stewardship in outpatient settings in the United States. Front Med. 2022 Jul 27; 9: 901980. https://doi.org/10.3389/fmed.2022.901980.
25. Ahmad I, Kubaev A, Zwamel AH, Baldaniya L, Kaur J, Rani B et al. Insights into Haemophilus macrolide resistance: A comprehensive systematic review and meta-analysis. PLoS Negl Trop Dis. 2025 Mar 4; 19(3): e0012878. doi: 10.1371/journal.pntd.0012878.
26. Pinheiro ET, Karygianni L, Attin T, Thurnheer T. Antibacterial Effect of High-Purity Nisin Alone and in Combination with D-Amino Acids or Chlorhexidine in an Endodontic-Like Biofilm Model. Antibiotics (Basel). 2021 Feb 2; 10(2): 149. doi: 10.3390/antibiotics10020149.
27. Samgane G, Karaçam S, Tunçer Ça?layan S. Unveiling the synergistic potency of chlorhexidine and azithromycin in combined action. Naunyn-Schmiedeberg's Arch Pharmacol 2024; 397: 5975–987. https://doi.org/10.1007/s00210-024-03010-0.
28. Mitra D, Yadav A, Prithyani S, John LE, Rodrigues S, Shah R. The antiplaque efficacy of lantibiotic Nisin extract mouthrinse. J Indian Soc Periodontol. 2019 Jan-Feb; 23(1): 31-34. doi: 10.4103/jisp.jisp_326_18.
29. Abay Celkan ?, Özdemir FN, Bekhedda N, Mottaghizadeh F, Akçelik N. In Vitro Assessment of the Antimicrobial and Antibiofilm Efficacy of Chlorhexidine, EDTA, and NaOCl in Combination with Nisin Against Enterococcus faecalis Isolates. Mikrobiyol Bul. 2025 Oct; 59(4): 437-451. Turkish. doi: 10.5578/mb.20250419.
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