Journal: Journal of Thoracic Disease

Article Title: Upper respiratory tract commensal Streptococcus oralis inhibits mycobacterial growth by producing bioactive molecules and inducing macrophage autophagy

doi: 10.21037/jtd-2026-2039

Figure Lengend Snippet: Screening of the anti-mycobacterial activity of throat swab-derived microbial culture supernatants from TB close contacts. (A) Effects of pooled throat swab-derived microbial culture supernatants on the in vitro growth of BCG. (B) Effects of culture supernatants derived from 12 individual participants on the in vitro growth of BCG. The red boxes highlight samples 5 and 11, which showed the most prominent inhibitory activity against BCG growth among all 12 individuals tested. (C) Representative colony images showing the inhibitory effects of culture supernatants from different individuals on BCG growth. (D-F) PMA-differentiated THP-1 macrophages were infected with BCG (D), H37Rv (E), or M. smegmatis (F), and treated with culture supernatants at the indicated concentrations; intracellular viable bacterial loads were then measured. For the H37Rv infection shown in (E), the 50% supernatant concentration was not tested owing to limited volume of the pooled supernatant. Results are expressed as the CFU index and presented as the mean ± standard deviation. *, P<0.05; **, P<0.01; ****, P<0.0001; ns, not significant. BCG, Bacillus Calmette-Guérin; CFU, colony-forming unit; TB, tuberculosis.

Article Snippet: The Mtb reference strain H37Rv (ATCC 27294), the attenuated Mycobacterium bovis Bacillus Calmette-Guérin (BCG) strain (ATCC 35733), and M. smegmatis (ATCC BAA-535) were maintained in our laboratory.

Techniques: Screening, Activity Assay, Derivative Assay, In Vitro, Infection, Concentration Assay, Standard Deviation

Journal: Journal of Thoracic Disease

Article Title: Upper respiratory tract commensal Streptococcus oralis inhibits mycobacterial growth by producing bioactive molecules and inducing macrophage autophagy

doi: 10.21037/jtd-2026-2039

Figure Lengend Snippet: Isolation, identification, and anti-mycobacterial activity validation of a functional S. oralis strain. (A) Effects of candidate functional strain culture supernatants on the in vitro growth of BCG. (B) Effects of culture supernatants from monoclonal isolates obtained from sample 11 on the in vitro growth of BCG; the red box indicates strain 11-9, which was selected for subsequent experiments. (C-E) Changes in viable intracellular H37Rv, BCG, and M. smegmatis burdens in THP-1-derived macrophages after treatment with the culture supernatant of strain 11-9. Results are expressed as the CFU index and presented as the mean ± standard deviation. *, P<0.05; **, P<0.01; ***, P<0.001; ****, P<0.0001. BCG, Bacillus Calmette-Guérin; CFU, colony-forming unit.

Article Snippet: The Mtb reference strain H37Rv (ATCC 27294), the attenuated Mycobacterium bovis Bacillus Calmette-Guérin (BCG) strain (ATCC 35733), and M. smegmatis (ATCC BAA-535) were maintained in our laboratory.

Techniques: Isolation, Activity Assay, Biomarker Discovery, Functional Assay, In Vitro, Derivative Assay, Standard Deviation

Journal: PLOS One

Article Title: Identifying optimal combination regimens for therapy of Mycobacterium tuberculosis with an algorithmic approach: prospective predictions and validations

doi: 10.1371/journal.pone.0324206

Figure Lengend Snippet: The organs were harvested from mice that were sacrificed 1 and 5 hours after they have received daily doses of these antibiotics for seven days. H&E stains of the lungs are also shown. The Kramnik mice were aerosol challenged with Mtb H37Rv 14 weeks prior to the initiation of antibiotic therapy.

Article Snippet: Mtb strain H37Rv ATCC 27294 was purchased from the American Type Culture Collection (Manassas, VA).

Techniques: Aerosol

Journal: BMC Infectious Diseases

Article Title: Non-continuous Percoll density gradient: a method for purifying Mycobacterium tuberculosis from dust

doi: 10.1186/s12879-025-12332-0

Figure Lengend Snippet: Schematic of the experimental workflow for method validation using H37Rv-spiked dust samples

Article Snippet: The MTB H37Rv reference strain (ATCC27294) was obtained from the American Type Culture Collection (ATCC, USA).

Techniques: Biomarker Discovery

Journal: BMC Infectious Diseases

Article Title: Non-continuous Percoll density gradient: a method for purifying Mycobacterium tuberculosis from dust

doi: 10.1186/s12879-025-12332-0

Figure Lengend Snippet: Determination of optimal Percoll density gradient for H37Rv separation from dust. ( A , D) Photographs of discontinuous ( A ) 5-layer and ( D ) 3-layer Percoll density gradients. Methylene blue was added to select layers during gradient preparation for visual clarity. The distinct interphases after centrifugation are formed by intrinsic density differences. Pure H37Rv (acid-fast stained, red bacilli) and unprocessed dust particles were layered. The pink background in the MTB sample tubes originates from the suspension medium of the stained bacilli; the actual localization of MTB is indicated by the turbid, cloudy bands at the density interfaces. ( B , E ) Quantitative comparison of H37Rv DNA recovery efficiency across gradient fractions, as determined by qPCR. Data are presented as mean ± SD ( n = 3). Statistical significance was analyzed by one-way ANOVA for multi-group comparisons and unpaired t-test for pairwise comparisons (*** p < 0.001, **** p < 0.0001). ( C ) Representative microscopic fields (1000× magnification) of acid-fast stained bacilli recovered from each layer of the 5-layer gradient (scale bar: 100 μm)

Article Snippet: The MTB H37Rv reference strain (ATCC27294) was obtained from the American Type Culture Collection (ATCC, USA).

Techniques: Centrifugation, Staining, Suspension, Comparison

Journal: BMC Infectious Diseases

Article Title: Non-continuous Percoll density gradient: a method for purifying Mycobacterium tuberculosis from dust

doi: 10.1186/s12879-025-12332-0

Figure Lengend Snippet: Viability assessment of H37Rv recovered via Percoll separation. ( A-E ) Macroscopic appearance of H37Rv colonies on LJ medium after 4 weeks of incubation. Left panels: Recovery standard controls (direct inoculation of pure H37Rv suspensions without dust). Right panels: Colonies recovered via Percoll separation from H37Rv-spiked dust samples. Initial spiking concentrations: ( A ) 10⁰, ( B ) 10¹, ( C ) 10², ( D ) 10³, ( E ) 10⁴ CFU/mL. ( F ) Quantitative comparison of viable MTB concentrations (CFU/mL) between Percoll-separated samples (from dust matrix) and direct inoculation controls (pure H37Rv). Colony counts were converted to CFU/mL for analysis. Bars represent mean ± SD ( n = 3). Statistical significance was determined by a paired t-test (ns, not significant; ** p < 0.01)

Article Snippet: The MTB H37Rv reference strain (ATCC27294) was obtained from the American Type Culture Collection (ATCC, USA).

Techniques: Incubation, Comparison

Journal: BMC Infectious Diseases

Article Title: Non-continuous Percoll density gradient: a method for purifying Mycobacterium tuberculosis from dust

doi: 10.1186/s12879-025-12332-0

Figure Lengend Snippet: Detection of MTB in air-conditioning dust from TB hospital wards using qPCR. ( A–D ) Representative qPCR amplification curves for MTB DNA detected in 25 clinical dust samples. Dashed lines: samples processed by Percoll separation. Solid lines: samples processed by direct DNA extraction. ( E ) qPCR amplification profiles for positive controls (H37Rv genomic DNA, red lines) and negative controls (no-template, green lines). ( F ) Examples of abnormal amplification curves obtained from the direct extraction method. ( G ) Violin plots comparing MTB DNA copy numbers between Percoll-based separation and direct extraction methods. Horizontal lines within violins represent the median and interquartile range. Statistical significance was determined by the Mann-Whitney U test (**** p < 0.0001)

Article Snippet: The MTB H37Rv reference strain (ATCC27294) was obtained from the American Type Culture Collection (ATCC, USA).

Techniques: Amplification, DNA Extraction, Extraction, MANN-WHITNEY