Sensitivity Patterns of Lozenge Formulation Against Selected Bacterial and Fungal Isolates Associated with Throat Infections.

Abstract

The increasing prevalence of antimicrobial resistance in common oral pathogens has necessitated the development of alternative therapeutic approaches. Lozenge formulations containing natural ingredients with antimicrobial properties offer potential treatment options for oral and pharyngeal infections. This study aimed to evaluate the sensitivity patterns of a lozenge formulation developed at Africa University against Staphylococcus aureus, Klebsiella pneumoniae, and Candida albicans. A laboratory-based experimental design was used to demonstrate in vitro antimicrobial activity, determine minimum inhibitory concentrations (MICs), and compare sensitivity patterns with known antibiotics. The disc diffusion method was used to determine and measure zones of inhibition, while the broth micro dilution method was used to determine MICs. Statistical analysis included Dunnett's Multiple Comparisons Test which was used to compare the zones of inhibition of the lozenge formulation against each known antibiotic. The lozenge formulation exhibited significant antimicrobial activity against S. aureus and K. pneumoniae with mean zones of inhibition of 13.0±2.1 mm and 16.4±2.4 mm, respectively, but showed no activity against C. albicans (0.0±0.0 mm). MIC values were determined to be 40.0% for Staphylococcus aureus and 50.0% for Klebsiella pneumoniae, with Candida albicans showing no inhibition at concentrations of up to 50.0%. Statistical analysis revealed significant differences in MIC values between Staphylococcus aureus and Candida albicans (p=0.019), confirming the greater susceptibility of Staphylococcus aureus to the lozenge formulation. Comparison with known antibiotics demonstrated that the lozenge formulation performed better than the known antibiotics, with relative potency values ranging from 86.7% to 328.0%. The lozenge formulation showed significantly higher inhibition against Staphylococcus aureus than all tested known antibiotics except tetracycline, while it demonstrated significantly higher inhibition than all tested antibiotics except ciprofloxacin against Klebsiella pneumoniae. The findings indicated that the lozenge formulation has potential as an alternative or adjunctive therapy for bacterial infections in the oral cavity, particularly those caused by Staphylococcus aureus and Klebsiella pneumoniae, which have shown increasing resistance to conventional antibiotics. However, the lack of activity against Candida albicans indicated that the formulation should not be used as a sole treatment for fungal infections in the oral cavity, and combination therapy with antifungal agents may be necessary. Further in vivo studies are recommended to evaluate the clinical efficacy and safety of the formulation, along with investigations into its chemical composition to identify the specific compounds responsible for its antimicrobial activity.