12 members of the Kaspar Lab presented poster presentations at the 2025 The Ohio State University College of Dentistry Research Day.

In addition, several members took home awards for their efforts:

Nicole Fleming – Alumni Research Achievement Award, will be going to the Hinman Student Research Symposium as a part of this prize (held in Fall 2025)

Robbie Bettinger – Alumni Research Merit Award, will be going to the Hinman Student Research Symposium as a part of this prize

3^rd Place Dental Student Award for Research Day 2025

Jarett Pittman — ADA Dentsply Award, will be going to the 2026 IADR/AADOCR General Meeting to compete in the Student Competition for Advancing Dental Research and its Application (SCADA)    Competition (held next March 2026)

2^nd Place Dental Student Award for Research Day 2025

Jacob Harris — 1^st Place PhD/Resident Student Award for Research Day 2025

Award winners from the Kaspar Lab at the 2025 College of Dentistry Research Day

The full presenters and titles are listed below:

DDS Student Category

Robbie Bettinger, D2 – Identification of genes that impacts fitness in Streptococcus gordonii (Award winner)

Nicole Fleming, D3 – Efficacy of oral healthcare antimicrobials on Streptococcus mutans clinical isolates (Award winner)

Jarett Pittman, D2 – Chlorhexidine tolerance in Streptococcus mutans isolates at a single-cell level (Award winner)

Iris Shin, D2 – Streptococcus sanguinis carbohydrate utilization pathways impacts growth with Streptococcus mutans 

Jacob Tuckerman, D3 – Assessing prevalence of viroid-like colonists in commensal oral streptococci

PhD/ Resident Category

Jacob Harris, 2nd year PhD – Identification of Streptococcus mutans conditionally essential genes within human saliva

Staff Category 

Alyssa Deever – New fluorescent strains of oral streptococci species

Undergraduate Category

Hamsika Arnipalli, Junior – Impacts of carbohydrates and metabolites on Rothia dentocariosa growth rates

Allen Choi, Senior – Human saliva modifies the behaviors of oral bacteria

Sarah Klingerman, Senior – Transformation efficiency of Streptococcus oralis: optimizing competence conditions

Huizhen Lim, Junior – Rothia dentocariosa antagonism of oral streptococci in coculture

Isabella Williams, Senior – Streptococcus mitis inhibits Streptococcus mutans biofilms via hydrogen peroxide production

Congrats to all of our presenters for their hard work this past year! 

The Kaspar Lab took home the prize for the “2024 Research Paper of the Year Award” in the Basic Science category at The Ohio State University College of Dentistry’s 2025 Research Day.

The paper, titled “Human saliva modifies growth, biofilm architecture, and competitive behaviors of oral streptococci” was published in February 2024 by the journal mSphere, an American Society of Microbiology (ASM) journal. Co-first authors on the manuscript included Allen Choi, a senior OSU student, Kevin Dong, a current D1 student, and Emily Williams, also a current D1 student within the College of Dentistry. Other authors included Lindsey Pia, a senior OSU student, Jordan Batagower, a current D2 at Texas A&M College of Dentistry, Paige Bending, a current D2 student, Iris Shin, also a current D2 student, Dan Peters, former lab technician in the Kaspar Lab currently in medical school at Ohio University Heritage College of Osteopathic Medicine, and Justin Kaspar.

The paper details how inclusion of human saliva into lab-based growth medias commonly used in oral microbiology positively influences the growth rates of several species of oral bacteria, including oral streptococci. In contrast, saliva negatively impacted biofilm formation of the same species. In addition, it was uncovered that inclusion of human saliva made the caries pathogen Streptococcus mutans more competitive against other species of oral streptococci, caused in part due to gene expression changes. This work reveals the importance of studying oral bacteria, as well as intermicrobial interactions, in lab conditions that more closely mimics their natural environments as lab conditions may not fully recapitulate what is actively occurring in the oral environment.

On Tuesday, February 25th, the latest publication from the Kaspar Lab was published in Applied and Environmental Microbiology, an ASM Journal. The title of the publication is “A strain of Streptococcus mitis inhibits biofilm formation of caries pathogens via abundant hydrogen peroxide production”.

Read the publication here. 

The study was led by Isabella Williams, a current Ohio State senior, and Jacob Tuckerman, a current D3 student within the College of Dentistry.

Other authors included Dan Peters, former lab technician, Madisen Bangs, a D1 student, Emily Williams, also a D1 student, Iris Shin, a D2 student, and Justin Kaspar.

The study originated from the finding that a strain of Streptococcus mitis, ATCC 49456, was observed to effectively inhibit the biofilm formation of caries pathogen Streptococcus mutans. The research uncovers that the source of the biofilm inhibition is due to high hydrogen peroxide production by S. mitis ATCC 49456, which was found to produce 4-5x more hydrogen peroxide than other strains tested in the study.

The study reinforces prior work from other groups that shows hydrogen peroxide production in oral commensal streptococci to be a main antagonistic factor against caries pathogens like S. mutans. In addition, select strains such as ATCC 49456 have the propensity to produce higher amounts of hydrogen peroxide than other strains, which can be a beneficial property used to combat odontopathogens. High hydrogen peroxide production may be a desirable trait in strains considered to be oral probiotic candidates, but further research is needed to determine why strains like ATCC 49456 produce higher amounts of hydrogen peroxide compared to other strains, and its potential effects on the broader microbiome.

A strain of Streptococcus mitis inhibits Streptococcus mutans biofilm formation. Figure 1 from Williams et al 2025.

Exploring How the Behavior of Microbes Change When They’re Together