Quantitative Assessment of Microbial Contamination and Patterns of Public Behaviour with Used Toothbrushes: Implications of Storage and Replacement

Peter Lambert,Amreen Bashir

doi:10.31487/j.dobcr.2021.02.08

Abstract

Introduction: Toothbrushes can readily become contaminated with microbes during use and storage. They present a potential hazard of cross-contamination and subsequent infection. Aims: To investigate the nature and level of microbial contamination of used toothbrushes and influence of participant lifestyle. Methods and Results: 103 used toothbrushes were donated, and microbial contents were determined by microbial culture and identification. 97% of toothbrushes revealed contamination. The microbial loads ranged from 0-1010 cfu/brush with median values of around 107, with Candida isolated in the highest levels. 90% of toothbrushes were stored in bathrooms presumably exposed to environmental contamination and 72% revealed the presence of enteric bacteria including Klebsiella, Serratia and Enterobacter. 50% of participants kept toothbrushes for >3 months and 40% retained toothbrushes for 4-6 months; microbial loads were fully established during the first three months of use and did not increase further with prolonged use. Only 57% of participants brushed their teeth twice a day and 41% brushed once a day. Conclusion: Used toothbrushes are heavily contaminated and the presence of potentially pathogenic microorganisms constitutes a potential health risk. Significance and Impact of Study: There is an under-recognised risk of cross-contamination/infection, especially when multiple users store toothbrushes in close contact. Guidance on toothbrush age, brushing frequency and storage is not being followed. Further education is required to improve public awareness.

Highlights

Toothbrushes can readily become contaminated with microbes during use and storage
The microbial loads ranged from 0-1010 cfu/brush with median values of around 107, with Candida isolated in the highest levels. 90% of toothbrushes were stored in bathrooms presumably exposed to environmental contamination and 72% revealed the presence of enteric bacteria including Klebsiella, Serratia and Enterobacter. 50% of participants kept toothbrushes for >3 months and 40% retained toothbrushes for 4-6 months; microbial loads were fully established during the first three months of use and did not increase further with prolonged use
Analysis of agar plates using standard laboratory tests including agar and biochemical properties revealed that 97% of used toothbrushes were contaminated and the presence of the following organisms was observed; Enterobacteriaceae comprising Escherichia coli (62%), Klebsiella species (55%), Enterobacter species (4%) and Serratia species (4%), Staphylococcus species (70%), non-fermenting Gram-negative bacteria (47%) and Candida species (77%)

Summary

Introduction

Toothbrushes can readily become contaminated with microbes during use and storage. They present a potential hazard of cross-contamination and subsequent infection. Aims: To investigate the nature and level of microbial contamination of used toothbrushes and influence of participant lifestyle. Conclusion: Used toothbrushes are heavily contaminated and the presence of potentially pathogenic microorganisms constitutes a potential health risk. Guidance on toothbrush age, brushing frequency and storage is not being followed. Pathogenic microorganisms can contaminate toothbrushes due to microbial transmission during use and from the environment. Following recommendations from dentists, the average person brushes their teeth twice daily, changing their toothbrush every 3-4 months [1, 2]. When microbiota balance is disrupted, the existing commensal microorganisms, and non-commensal organisms, can cause disease

Objectives

Results

Conclusion