reference strain mrsa atcc 43300  (ATCC)

Journal: AMB Express

Article Title: Repurposed bunamidine disrupts envelope energetics and induces ROS-mediated non-lytic killing

doi: 10.1186/s13568-026-02016-6

Figure Lengend Snippet: Antibacterial activity of BUN against MRSA. A Chemical structure of bunamidine hydrochloride (BUN). B MIC determinations of BUN against MRSA ATCC 43300 and USA300 in MH and TSB media. C XTT assays showing concentration-dependent inhibition of metabolic activity by BUN. D Comparison of OD 630 changes over time between BUN and the bacteriostatic comparator LZD. E Time-kill kinetics demonstrating concentration-dependent bactericidal activity of BUN. F Live/dead staining of MRSA using SYTO9/PI probes after 2 h exposure to BUN. G Quantification of PI-positive (dead) cells following BUN treatment. Data are presented as mean ± SD from at least three independent experiments. Statistical analyses were performed using one-way ANOVA with post hoc comparisons; ns, not significant; * P < 0.05; ** P < 0.01; *** P < 0.001; **** P < 0.0001

Article Snippet: Time-kill assays demonstrated that BUN at 4 μg/mL eradicated persister cells of both the reference strain MRSA ATCC 43300 and the clinically relevant MRSA USA300 isolate within 2 h, whereas vancomycin and daptomycin, even at 10 × MIC, showed minimal activity under identical conditions (Fig. G).

Techniques: Activity Assay, Concentration Assay, Inhibition, Comparison, Staining

Journal: AMB Express

Article Title: Repurposed bunamidine disrupts envelope energetics and induces ROS-mediated non-lytic killing

doi: 10.1186/s13568-026-02016-6

Figure Lengend Snippet: Antibiofilm and anti-persister activity of BUN against MRSA. A , B Biofilm inhibition ( A ) and eradication ( B ) of MRSA ATCC 43300 determined by CV (biomass) and XTT (metabolic activity) assays after exposure to BUN (0–16 µg/mL) in TSBg for 24 h. Statistical significance was evaluated by one-way ANOVA with Dunnett’s test versus control (ns, * P < 0.05, ** P < 0.01, *** P < 0.001, **** P < 0.0001). C , D CLSM images of biofilms stained with SYTO9 (green) and PI (red) under inhibition ( C ) and eradication ( D ) conditions following BUN treatment (4 or 8 µg/mL). Scale bars, 20 µm. E , F Quantification of live/dead cell ratios from representative CLSM fields. G Time-kill curves of biofilm-associated persister cells from MRSA ATCC 43300 and USA300 challenged with BUN (4 µg/mL) or comparators [VAN and DAP, 10 × MIC]. Dashed line indicates the limit of detection. Data are presented as mean ± SD from independent experiments

Article Snippet: Time-kill assays demonstrated that BUN at 4 μg/mL eradicated persister cells of both the reference strain MRSA ATCC 43300 and the clinically relevant MRSA USA300 isolate within 2 h, whereas vancomycin and daptomycin, even at 10 × MIC, showed minimal activity under identical conditions (Fig. G).

Techniques: Activity Assay, Inhibition, Control, Staining

Journal: AMB Express

Article Title: Repurposed bunamidine disrupts envelope energetics and induces ROS-mediated non-lytic killing

doi: 10.1186/s13568-026-02016-6

Figure Lengend Snippet: Structural perturbation, hemolytic assessment, and ROS involvement in BUN activity. A Transmission electron microscopy images of MRSA ATCC 43300 showing morphological changes after BUN treatment compared with untreated controls. B Hemolysis of freshly isolated human red blood cells in the presence of BUN. Hemoglobin release was measured spectrophotometrically. C Effect of glutathione (GSH) supplementation on the MIC of BUN against MRSA ATCC 43300 and USA300. D Confocal fluorescence imaging of intracellular ROS in MRSA ATCC 43300 using DCFH-DA probe, with or without GSH supplementation. Bright-field images are shown for comparison. Scale: 200 μm

Article Snippet: Time-kill assays demonstrated that BUN at 4 μg/mL eradicated persister cells of both the reference strain MRSA ATCC 43300 and the clinically relevant MRSA USA300 isolate within 2 h, whereas vancomycin and daptomycin, even at 10 × MIC, showed minimal activity under identical conditions (Fig. G).

Techniques: Activity Assay, Transmission Assay, Electron Microscopy, Isolation, Fluorescence, Imaging, Comparison