Pneumonia-associated microbial species and stabilized chlorine dioxide–containing oral care products

Abstract

Background

This study evaluated the antifungal and antibacterial effects of stabilized chlorine dioxide–containing oral care products against yeast and bacterial species associated with pneumonia.

Methods

Six yeast species (Candida albicans, Candida glabrata, Cryptococcus neoformans, Candida dubliniensis, Candida krusei, Candida tropicalis) and 5 bacterial species (Streptococcus pneumoniae, Klebsiella pneumoniae, Haemophilus influenzae, Staphylococcus aureus, Pseudomonas aeruginosa) were grown in Sabouraud dextrose broth and brain-heart infusion media, respectively, overnight. Each microorganism was treated with individual chlorine dioxide–containing ClōSYS (Rowpar Pharmaceuticals) products (Silver Multi-Benefit Fluoride Mouthwash, Sensitive Fresh Breath Mouthwash, Ultra Sensitive Mouthwash, Oral Spray, Silver Toothpaste, Sensitive Toothpaste, Fluoride-free Toothpaste) at serial dilutions. Chlorhexidine gluconate (0.12%) mouthrinse and water were positive and negative controls, respectively. Treated species were grown overnight. Minimum inhibitory concentration (MIC) was evaluated. Five microliters of each culture were transferred to blood agar plates incubated overnight, and minimum fungicidal concentration (MFC) and minimum bactericidal concentrations (MBC) were evaluated.

Results

All undiluted products produced antifungal effects against tested yeast species. Similarly, antibacterial effects were observed for all products except for S pneumoniae and H influenzae, which were resistant to killing by some products. All tested products produced fungistatic or bacteriostatic effects against tested fungal or bacterial species. Different concentrations of each product are required to produce MIC, MFC, and MBC for each species tested. Some species required an equal or higher MIC than MFC and MBC.

Conclusions

Stabilized chlorine dioxide–containing ClōSYS oral care products exhibit antifungal and antibacterial effects against common yeast and bacterial species associated with pneumonia.