Journal: Journal of Biomedical Science

Article Title: Phage–antibiotic synergy restores β-lactam efficacy in MDR Klebsiella quasipneumoniae biofilms and suppresses resistance

doi: 10.1186/s12929-026-01218-1

Figure Lengend Snippet: Assessment of PAS effects on planktonic K. quasipneumoniae ATCC 700603. A – E Bacterial growth curves under different treatment conditions (as indicated in the diagrams). The concentrations of CAZ as the fold change in the MIC (MIC CAZ = 32 mg/L) and phage titers are indicated in the legends. The data are presented as the means ± standard deviations (SDs, n = 3)

Article Snippet: Notably, the widely used quality-control strain ATCC 700603, originally labeled K. pneumoniae , has since been reclassified as K. quasipneumoniae subsp. similipneumoniae (hereafter referred to simply as K. quasipneumoniae ) [ ].

Techniques:

Journal: Journal of Biomedical Science

Article Title: Phage–antibiotic synergy restores β-lactam efficacy in MDR Klebsiella quasipneumoniae biofilms and suppresses resistance

doi: 10.1186/s12929-026-01218-1

Figure Lengend Snippet: Quantitative evaluation of treatment effects on K. quasipneumoniae ATCC 700603 biofilms following exposure to CAZ (0.25 × MIC), phage vB_KpUKJ_2 (10 8 PFU/mL), or their combination. A Surface area covered (SAC) by viable biofilm (in %) over time, as determined by the calcein fluorescence signal after staining with CAM. A total pixel area of 2048 × 2048 µm was analyzed from LSFM micrographs; B AUC representation of the kinetic data from ( A ) over a treatment period of 0–24 h, based on relative fluorescence units (RFU) × h; C Viable bacterial counts (CFU/mL) after biofilm treatments at three distinct time points. Statistical analysis was performed via two-way ANOVA followed by Tukey’s multiple comparisons test. D Phage particles (PFU/mL) after combined biofilm treatment at three time points. Statistical analysis was conducted via one-way ANOVA followed by Dunnett’s post hoc test. The data are presented as the means ± SDs (n = 3). Significance was assumed at p < 0.05 and is indicated by asterisks: * p < 0.05; ** p < 0.01; *** p < 0.001; **** p < 0.0001

Article Snippet: Notably, the widely used quality-control strain ATCC 700603, originally labeled K. pneumoniae , has since been reclassified as K. quasipneumoniae subsp. similipneumoniae (hereafter referred to simply as K. quasipneumoniae ) [ ].

Techniques: Fluorescence, Staining

Journal: Journal of Biomedical Science

Article Title: Phage–antibiotic synergy restores β-lactam efficacy in MDR Klebsiella quasipneumoniae biofilms and suppresses resistance

doi: 10.1186/s12929-026-01218-1

Figure Lengend Snippet: Representative CLSM images showing the effects of phage vB_KpUKJ_2 (10 8 PFU/mL) on mature K. quasipneumoniae ATCC 700603 biofilms at 0, 4, and 24 h post-treatment. Biofilms were stained with Con-A (green) for α-polysaccharides or with CFW (magenta) for β-polysaccharides to visualize extracellular matrix integrity. A Untreated control, B phage-treated samples. To minimize photobleaching and laser-induced biofilm disruption, independent samples were used for each time point. Each image represents a representative Z-stack projection from three independent experiments. Scale bars: 20 μm

Article Snippet: Notably, the widely used quality-control strain ATCC 700603, originally labeled K. pneumoniae , has since been reclassified as K. quasipneumoniae subsp. similipneumoniae (hereafter referred to simply as K. quasipneumoniae ) [ ].

Techniques: Staining, Control, Disruption

Journal: Journal of Biomedical Science

Article Title: Phage–antibiotic synergy restores β-lactam efficacy in MDR Klebsiella quasipneumoniae biofilms and suppresses resistance

doi: 10.1186/s12929-026-01218-1

Figure Lengend Snippet: Characteristics of six phage-resistant mutants in comparison with the parental K. quasipneumoniae ATCC 700603 strain. A Differences in the AUCs based on growth kinetics. B Biofilm formation ability at 48 h quantified by crystal violet staining and absorbance measured at 570 nm; the data are presented as the means ± SDs (n = 3). Statistical analyses were performed via one-way ANOVA followed by Tukey’s multiple comparisons test. Significance was assumed at p < 0.05 and is indicated by asterisks: * p < 0.05; ** p < 0.01; *** p < 0.001; **** p < 0. 0001

Article Snippet: Notably, the widely used quality-control strain ATCC 700603, originally labeled K. pneumoniae , has since been reclassified as K. quasipneumoniae subsp. similipneumoniae (hereafter referred to simply as K. quasipneumoniae ) [ ].

Techniques: Comparison, Staining

Journal: Frontiers in Immunology

Article Title: The Rho GTPase signaling pathway modulates Moraxella catarrhalis invasion into human respiratory epithelial cells by regulating actin polymerization

doi: 10.3389/fimmu.2026.1730864

Figure Lengend Snippet: Critical role of CDC42 in the Rho GTPase signaling pathway during M. catarrhalis invasion into A549 cells. (A) Comparison of invasion counts of M. catarrhalis strains 73-OR and ATCC 25238 into WT A549 cells vs. CDC42 -/- A549 cells. Data are presented as mean ± standard error (SE) from three independent biological replicates (n=3). Statistical significance was determined using an unpaired Student’s t-test. To accurately assess the magnitude of the impact given the limited sample size, effect sizes (Cohen’s d) and mean differences are reported alongside P-values. (B) Transmission electron micrographs (TEM) of 73-OR and ATCC 25238 invading WT A549 cells and CDC42 -/- A549 cells. (C) TEM quantification of M. catarrhalis invasion into wild-type and CDC42 -/- A549 cells. Invasion counts for M. catarrhalis strains 73-OR and ATCC 25238 were quantified by counting the number of bacteria internalized within wild-type (WT) and CDC42 -/- A549 cells via Transmission Electron Microscopy (TEM). Data represent the mean ± standard error(SE) from three independent biological replicates (n =3). Within each biological replicate, three random microscopic fields at the same magnification were selected and counted. Statistical significance between groups was determined using the non-parametric Mann-Whitney U test. Both 73-OR and ATCC 25238 strains showed a significant reduction in invasion into CDC42 -/- A549 cells compared to WT cells. (D) Quantitative comparison of F-actin/G-actin ratios in WT A549 cells and CDC42 -/- A549 cells post-infection with M. catarrhalis strains 73-OR and ATCC 25238. Data are presented as the mean ± standard error(SE) from three independent biological replicates (n=3). Statistical comparison between groups was performed using an unpaired Student’s t-test. (E) Immunofluorescence analysis of F-actin polymerization in A549 cells post-infection. Wild-type (WT) and CDC42 -/- A549 cells were challenged with M. catarrhalis strains 73-OR and ATCC 25238, fixed, and stained. Blue: nuclei; Green: F-actin. (F) Analysis of microfilament expression levels in WT A549 cells vs. CDC42 -/- A549 cells following infection with 73-OR and ATCC 25238. Data are presented as the mean ± standard error(SE) from three independent biological replicates (n=3). Statistical comparison between groups was performed using an unpaired Student’s t-test.

Article Snippet: The M. catarrhalis . quality control strain ATCC-25238 and the representative strain with strong invasion ability 73-OR should be included in future studies to confirm the universality of these findings.

Techniques: Comparison, Transmission Assay, Bacteria, Electron Microscopy, MANN-WHITNEY, Infection, Immunofluorescence, Staining, Expressing

Journal: Frontiers in Immunology

Article Title: The Rho GTPase signaling pathway modulates Moraxella catarrhalis invasion into human respiratory epithelial cells by regulating actin polymerization

doi: 10.3389/fimmu.2026.1730864

Figure Lengend Snippet: Critical role of Rac1 in the Rho GTPase signaling pathway during M. catarrhalis invasion into A549 cells. (A) Comparison of invasion counts of M. catarrhalis strains 73-OR and ATCC 25238 into WT A549 cells vs. Rac1 -/- A549 cells. Data are presented as mean ± standard error (SE)from three independent biological replicates (n=3). Statistical significance was determined using an unpaired Student’s t-test. To accurately assess the magnitude of the impact given the limited sample size, effect sizes (Cohen’s d) and mean differences are reported alongside P-values. (B) Transmission electron micrographs (TEM) of 73-OR and ATCC 25238 invading WT A549 cells and Rac1 -/- A549 cells. (C) TEM quantification of M. catarrhalis invasion into wild-type and Rac1 -/- A549 cells. Invasion counts for M. catarrhalis strains 73-OR and ATCC 25238 were quantified by counting the number of bacteria internalized within wild-type (WT) and Rac1 -/- A549 cells via Transmission Electron Microscopy (TEM). Data represent the mean ± standard error(SE) from three independent biological replicates (n=3). Within each biological replicate, three random microscopic fields at the same magnification were selected and counted. Statistical significance between groups was determined using the non-parametric Mann-Whitney U test. Both 73-OR and ATCC 25238 strains showed a significant reduction in invasion into Rac1 -/- A549 compared to WT cells. (D) Quantitative comparison of F-actin/G-actin ratios in WT A549 cells and Rac1 -/- A549 cells post-infection with M. catarrhalis strains 73-OR and ATCC 25238. Data are presented as the mean± standard error(SE) from three independent biological replicates (n=3). Statistical comparison between groups was performed using an unpaired Student’s t-test. (E) Immunofluorescence analysis of F-actin polymerization in A549 cells post-infection.Wild-type (WT) and Rac1 -/- A549 cells were challenged with M. catarrhalis strains 73-OR and ATCC 25238, fixed, and stained. Blue: nuclei; Green: F-actin. (F) Analysis of microfilament expression levels in WT A549 cells vs. Rac1 -/- A549 cells following infection with 73-OR and ATCC 25238. Data are presented as the mean ± standard error(SE) from three independent biological replicates (n=3). Statistical comparison between groups was performed using an unpaired Student’s t-test.

Article Snippet: The M. catarrhalis . quality control strain ATCC-25238 and the representative strain with strong invasion ability 73-OR should be included in future studies to confirm the universality of these findings.

Techniques: Comparison, Transmission Assay, Bacteria, Electron Microscopy, MANN-WHITNEY, Infection, Immunofluorescence, Staining, Expressing

Journal: Frontiers in Immunology

Article Title: The Rho GTPase signaling pathway modulates Moraxella catarrhalis invasion into human respiratory epithelial cells by regulating actin polymerization

doi: 10.3389/fimmu.2026.1730864

Figure Lengend Snippet: Critical role of ArpC2 in the Rho GTPase signaling pathway during M. catarrhalis invasion into A549 cells. (A) Comparison of invasion counts of M. catarrhalis strains 73-OR and ATCC 25238 into WT A549 cells vs. ArpC2 -/- A549 cells. Data are presented as mean ± standard error (SE)from three independent biological replicates (n=3). Statistical significance was determined using an unpaired Student’s t-test. To accurately assess the magnitude of the impact given the limited sample size, effect sizes (Cohen’s d) and mean differences are reported alongside P-values. (B) Transmission electron micrographs (TEM) of 73-OR and ATCC 25238 invading WT A549 cells and ArpC2 -/- A549 cells. (C) TEM quantification of M. catarrhalis invasion into wild-type and ArpC2 -/- A549 cells. Invasion counts for M. catarrhalis strains 73-OR and ATCC 25238 were quantified by counting the number of bacteria internalized within wild-type (WT) and ArpC2 -/- A549 cells via Transmission Electron Microscopy (TEM). Data represent the mean ± standard error(SE) from three independent biological replicates (n =3). Within each biological replicate, three random microscopic fields at the same magnification were selected and counted. Statistical significance between groups was determined using the non-parametric Mann-Whitney U test. (D) Quantitative comparison of F-actin/G-actin ratios in WT A549 cells and ArpC2 -/- A549 cells post-infection with M. catarrhalis strains 73-OR and ATCC 25238. Data are presented as the mean ± standard error(SE) from three independent biological replicates (n=3). Statistical comparison between groups was performed using an unpaired Student’s t-test. (E) Immunofluorescence analysis of F-actin polymerization in A549 cells post-infection. Wild-type (WT) and ArpC2 -/- A549 cells were challenged with M. catarrhalis strains 73-OR and ATCC 25238, fixed, and stained. Blue: nuclei; Green: F-actin. (F) Analysis of microfilament expression levels in WT A549 cells vs ArpC2 -/- A549 cells following infection with 73-OR and ATCC 25238. Data are presented as the mean ± standard error(SE) from three independent biological replicates (n=3). Statistical comparison between groups was performed using an unpaired Student’s t-test.

Article Snippet: The M. catarrhalis . quality control strain ATCC-25238 and the representative strain with strong invasion ability 73-OR should be included in future studies to confirm the universality of these findings.

Techniques: Comparison, Transmission Assay, Bacteria, Electron Microscopy, MANN-WHITNEY, Infection, Immunofluorescence, Staining, Expressing

Journal: Frontiers in Immunology

Article Title: The Rho GTPase signaling pathway modulates Moraxella catarrhalis invasion into human respiratory epithelial cells by regulating actin polymerization

doi: 10.3389/fimmu.2026.1730864

Figure Lengend Snippet: Critical role of ArpC4 in the Rho GTPase signaling pathway during M. catarrhalis invasion into A549 cells. (A) Comparison of invasion counts of M. catarrhalis strains 73-OR and ATCC 25238 into WT A549 cells vs. ArpC4 -/- A549 cells. Data are presented as mean ± standard error (SE)from three independent biological replicates (n=3). Statistical significance was determined using an unpaired Student’s t-test. To accurately assess the magnitude of the impact given the limited sample size, effect sizes (Cohen’s d) and mean differences are reported alongside P-values. (B) Transmission electron micrographs (TEM) of 73-OR and ATCC 25238 invading WT A549 cells and ArpC4 -/- A549 cells. (C) TEM quantification of M. catarrhalis invasion into wild-type and ArpC4 -/- A549 cells. Invasion counts for M.catarrhalis strains 73-OR and ATCC 25238 were quantified by counting the number of bacteria internalized within wild-type (WT) and ArpC4 -/- A549 cells via Transmission Electron Microscopy (TEM). Data represent the mean ± standard error(SE) from three independent biological replicates (n=3). Within each biological replicate, three random microscopic fields at the same magnification were selected and counted. Statistical significance between groups was determined using the non-parametric Mann-Whitney U test. (D) Quantitative comparison of F-actin/G-actin ratios in WT A549 cells and ArpC4 -/- A549 cells post-infection with M. catarrhalis strains 73-OR and ATCC 25238. Data are presented as the mean ± standard error(SE) from three independent biological replicates (n=3). Statistical comparison between groups was performed using an unpaired Student’s t-test. (E) Immunofluorescence analysis of F-actin polymerization in A549 cells post-infection. Wild-type (WT) and ArpC4 -/- A549 cells were challenged with M. catarrhalis strains 73-OR and ATCC 25238, fixed, and stained. Blue: nuclei; Green: F-actin. (F) Analysis of microfilament expression levels in WT A549 cells vs ArpC4 -/- A549 cells following infection with 73-OR and ATCC 25238. Data are presented as the mean ± standard error(SE) from three to four independent biological replicates (n=3-4). Statistical comparison between groups was performed using an unpaired Student’s t-test.

Article Snippet: The M. catarrhalis . quality control strain ATCC-25238 and the representative strain with strong invasion ability 73-OR should be included in future studies to confirm the universality of these findings.

Techniques: Comparison, Transmission Assay, Bacteria, Electron Microscopy, MANN-WHITNEY, Infection, Immunofluorescence, Staining, Expressing