fnn atcc 25586  (ATCC)

Journal: bioRxiv

Article Title: AI-2 Production in Fusobacterium nucleatum Is Subspecies-Specific and Uncoupled from Quorum Sensing

doi: 10.64898/2026.03.02.709096

Figure Lengend Snippet: (A) Phylogenetic relationship of representative F. nucleatum strains used in this study, grouped by subspecies—subsp. nucleatum (FNN; ATCC 25586, ATCC 23726, CTI-2), subsp. vincentii (FNV; 3_1_27, ATCC 49256, ATCC 51190), subsp. animalis (FNA; 7_1, F0401, ATCC 51191), and subsp. polymorphum (FNP; ATCC 10953, 12230). The phylogenetic tree was constructed based on znpA gene using the maximum-likelihood method implemented in DNAMAN Version 10 (Lynnon Biosoft). Fusobacterium periodonticum ATCC 33693 (FP) was included as an outgroup. (B) Schematic of the chromosomal region between uraA and pepF showing subspecies-specific presence of luxS . luxS is absent from FNN and FNV at this locus, present as an intact gene in FNA (between uraA and pepF ), and disrupted in FNP by insertion of an IS200-family element. The corresponding region from F. periodonticum is shown for comparison. Arrows indicate gene orientation; uraA (gray), pepF (black), luxS (blue), IS200 insertion (magenta), and the adjacent gene ( ddpA , orange) are indicated. (C) AI-2 activity in cell-free culture supernatants was measured using the Vibrio harveyi BB170 bioluminescence reporter assay. Supernatants from FNN, FNV, and FNP strains showed signals at or near background levels, whereas all tested FNA strains and F. periodonticum generated robust reporter induction. E. coli wild type (WT) and its Δ luxS mutant served as positive and negative controls, respectively. Data are presented as relative fluorescence units (RFU; mean ± SD) from three independent experiments (each assayed in technical triplicate); the y-axis includes a break to display both low- and high-signal samples.

Article Snippet: To generate a markerless Δ luxS mutant in FNA strain 7_1, the deletion plasmid pBCG10-Δ luxS was first introduced into E. coli SZU604, which expresses three F. nucleatum methyltransferases derived from FNN ATCC 25586( ).

Techniques: Construct, Comparison, Activity Assay, Reporter Assay, Generated, Mutagenesis, Fluorescence

Journal: bioRxiv

Article Title: AI-2 Production in Fusobacterium nucleatum Is Subspecies-Specific and Uncoupled from Quorum Sensing

doi: 10.64898/2026.03.02.709096

Figure Lengend Snippet: (A) Schematic of the uraA–pepF chromosomal locus in FNN ATCC 23726 before (WT) and after in-frame insertion of the FNA 7_1 luxS gene (WT:: luxS 7_1 ) between uraA and pepF . (B) PCR confirming correct chromosomal insertion of luxS 7_1 in ATCC 23726 (WT band versus the larger amplicon from WT:: luxS 7_1). (C) AI-2 activity measured by the V. harveyi BB170 bioluminescence reporter assay. WT ATCC 23726 and WT ATCC 25586 showed background-level signals, whereas ATCC 23726 carrying the chromosomal luxS 7_1 insertion (WT:: luxS 7_1 ) and ATCC 25586 expressing luxS 7_1 from a shuttle plasmid (p luxS 7_1 ) produced robust AI-2 signals comparable to the E. coli WT positive control. The E. coli Δ luxS strain served as a negative control. (D) Growth analysis showing that expression of luxS 7_1 in ATCC 23726 (WT:: luxS 7_1 ) or ATCC 25586 (p luxS 7_1 )) did not significantly alter final culture density relative to the corresponding WT strains (n.s., Student’s t test). (E) Representative crystal violet–stained monospecies biofilms demonstrating no obvious difference in biofilm biomass between WT and luxS 7_1 -expressing derivatives of ATCC 23726 and ATCC 25586 after anaerobic growth in TSPC for 72 h.

Article Snippet: To generate a markerless Δ luxS mutant in FNA strain 7_1, the deletion plasmid pBCG10-Δ luxS was first introduced into E. coli SZU604, which expresses three F. nucleatum methyltransferases derived from FNN ATCC 25586( ).

Techniques: Amplification, Activity Assay, Reporter Assay, Expressing, Plasmid Preparation, Produced, Positive Control, Negative Control, Staining