Work

A Defined Artificial Saliva Medium Allows Characterization of the Hypothiocyanite Response of Streptococcus sanguinis and Streptococcus mutans

Year: 2025

Type: article

Abstract: /HOSCN) is an antimicrobial molecule found at high concentrations in saliva. HOSCN is thought to differentially affect oral streptococci, since noncariogenic streptococci (e.g. Streptococcus sanguinis) possess HOSCN reductase activity that cariogenic streptococci (e.g. Streptococcus mutans) lack. However, the enzyme responsible for this activity and the effects of HOSCN and HOSCN reductase activity on biofilm formation by oral streptococci have not been previously established. In this work, we developed an artificial saliva medium for growth of oral streptococci with minimal redox-active components, called Defined Recipe Optimized Oral Liquid (DROOL), and used it to characterize the HOSCN responses of S. sanguinis and S. mutans. We identified a homolog of the Streptococcus pneumoniae Har protein in S. sanguinis as HOSCN reductase. S. mutans wild-type and S. sanguinis ∆har mutants were more sensitive to inhibition by physiological concentrations of HOSCN in DROOL than wild-type S. sanguinis when grown planktonically. S. mutans biofilm formation and glucan production were strongly decreased by HOSCN treatment, suggesting HOSCN inhibits S. mutans exopolysaccharide production. Collectively, our data demonstrate the specific ability of HOSCN to inhibit functions of cariogenic but not noncariogenic oral streptococci and show that Har is responsible for mediating this difference.

Source: Molecular Oral Microbiology

DOI: 10.1111/omi.70008

Authors: Avery D. Lieber, Drashti Vaghasia, Christopher W. Hamm, Michael J. Gray

Institutions: University of Alabama at Birmingham, UAB Medicine

Language: English

Topic: Oral microbiology and periodontitis research

Subfield: Periodontics

Field: Dentistry

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: hybrid

Estimated APC paid: $4,250