{"doi":"10.1101/2024.08.06.606862","title":"A Strain of <i>Streptococcus mitis</i> Inhibits Biofilm Formation of Caries Pathogens via Abundant Hydrogen Peroxide Production","abstract":"Commensal oral streptococci that colonize supragingival biofilms deploy mechanisms to combat competitors within their niche. Here, we determined that Streptococcus mitis more effectively inhibited biofilm formation of Streptococcus mutans within a seven species panel. This phenotype was common amongst all assayed isolates of S. mutans , but was specific to a single strain of S. mitis , ATCC 49456. The growth inhibitory factor was not effectively carried in spent supernatants of S. mitis . However, we documented ATCC 49456 to accumulate 4-5 times more hydrogen peroxide (H 2 O 2 ) than other species tested, and 5-18 times more than other S. mitis strains assayed. The S. mutans biofilm formation inhibitory phenotype was reduced when grown in media containing catalase or with a S. mitis mutant of pyruvate oxidase ( spxB ; pox ), confirming that SpxB-dependent H 2 O 2 production was the main antagonistic factor. Addition of S. mitis within hours after S. mutans inoculation was effective at reducing biofilm biomass, but not for 24 h pre-formed biofilms. Transcriptome analysis revealed responses for both S. mitis and S. mutans , with several S. mutans differentially expressed genes following a gene expression pattern previously described, while others being unique to the interaction with S. mitis . Finally, we show that S. mitis also affected coculture biofilm formation of several other commensal streptococci. Our study shows that strains with abundant H 2 O 2 production are effective at inhibiting initial growth of caries pathogens like S. mutans , but are less effective at disrupting pre-formed biofilms and have the potential to influence the stability of other oral commensal strains.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2024,"id":501903,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":0,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9556,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2024-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1351741,"name":"Jacob S. Tuckerman","orcid":null,"position":1,"is_corresponding":false},{"id":1172717,"name":"D. Peters","orcid":"0009-0005-5608-1289","position":2,"is_corresponding":false},{"id":1351742,"name":"Madisen Bangs","orcid":null,"position":3,"is_corresponding":false},{"id":1172714,"name":"Emily Williams","orcid":"0009-0008-6843-8304","position":4,"is_corresponding":false},{"id":1173068,"name":"Iris J. Shin","orcid":null,"position":5,"is_corresponding":false},{"id":481472,"name":"Justin R. Kaspar","orcid":"0000-0001-6901-5524","position":6,"is_corresponding":false},{"id":1351740,"name":"Isabella Williams","orcid":null,"position":0,"is_corresponding":true}],"reference_count":42,"raw_metadata":null,"created_at":"2026-07-19T02:10:19.647285Z","pmid":"39149263","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}