A Comparison Between Different Susceptibility Test Methods to Evaluate the Antibacterial Activity of Olibanum and Alum Against the "Red Complex" Periodontal Pathogens

Abstract

Testing the sensitivity of periodontal pathogens requires the selection of an easier and more reliable method to be used with such anaerobic bacteria that need a long period of time for growth. Natural materials are a new era of antibacterial agents to control periodontal infections. The aims of the current study were to test the antibacterial activity of two natural agents, namely olibanum and alum, against three types of red complex periodontal pathogens and compare the application of agar diffusion and microdilution methods for testing the susceptibility. Gingival crevicular fluid from pockets with chronic infections was sampled as a source for the three types of bacteria, Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola (the red complex pathogens). The samples (n= 30) were cultured on three types of media, namely Schaedler Anaerobe Agar, Tannerella forsythia (TF) agar, and Trypton Yeast extract Gelatin Volatile fatty acids and Serum (TYGVS) agar for the three types of red complex pathogens. After anaerobic growth, the isolates of red complex pathogens were identified by cultural and cellular morphological characteristics and confirmed by molecular diagnosis. The antibacterial activity of the two natural materials was tested by agar (disk and well) diffusion and microdilution method (spectrophotometer- and resazurin- based). Ciprofloxacin (CIP) and chlorhexidine (CHX) were used as controls. Minimal Inhibitory Concentrations (MICs) of the four reagents (olibanum, alum, CIP, and CHX) were determined on the three types of bacteria. MIC values by each susceptibility method were compared and analyzed statistically at p- value ≤ 0.05. The results showed that resazurin- based microdilution method was the easiest and simplest approach which gave reliable reads. MIC values of the four regents differed from a method to another and from one bacterium to another. Statistically, there were no significant values among these differences, except for olibanum which was statistically more significant than the other reagents.

Antibacterial Activity of Boswellia sacra Flueck. Oleoresin Extract against Porphyromonas gingivalis Periodontal Pathogen

“…Al-Hamdoni and Al-Rawi [30] reported that frankincense extract exhibited antibacterial activity against the red complex periodontal pathogens isolated from patients in Mosul, Iraq with MIC value of 2.4 mg/mL. The difference between the MIC values reported in the current study and that of Al-Hamdoni and Al-Rawi [16,30] could be explained by the finding reported by Di Stefano et al [40]. They noticed that frankincense essential oils derived from three different Boswellia sacra cultivars had different MIC values against Staphylococcus aureus, Pseudomonas aeruginosa, and Propionibacterium acnes standard isolates.…”

“…Hence, the need to use local antiseptics or systemic antibiotic therapy is recommended to improve the treatment outcome [15]. Systemic antibiotics are of great benefit as they reach the periodontal tissues via blood to suppress periodontal pathogens [16]. However, the emergence of antibiotic-resistant bacteria has made infectious diseases more difficult to treat [17].…”