Persister Cell Formation and Elevated <i>lsrA</i> and <i>lsrC</i> Gene Expression upon Hydrogen Peroxide Exposure in a Periodontal Pathogen <i>Aggregatibacter actinomycetemcomitans</i>

Abstract

The effect of hydrogen peroxide, an antiseptic dental treatment, on Aggregatibacter actinomycetemcomitans, the main causative agent of localized invasive periodontitis, was investigated. Hydrogen peroxide treatment (0.06%, 4× minimum inhibitory concentration) resulted in the persistence and survival of approximately 0.5% of the bacterial population. The surviving bacteria did not genetically acquire hydrogen peroxide resistance but exhibited a known persister behavior. Sterilization with mitomycin C significantly reduced the number of A. actinomycetemcomitans persister survivors. RNA sequencing of hydrogen peroxide-treated A. actinomycetemcomitans showed elevated expression of Lsr family members, suggesting a strong involvement of autoinducer uptake. In this study, we found a risk of A. actinomycetemcomitans persister residual from hydrogen peroxide treatment and hypothesized associated genetic mechanisms of persister from RNA sequencing.

Keywords

• <i>Aggregatibacter actinomycetemcomitans</i>
• hydrogen peroxide
• persister
• periodontitis