mtb strain h37rv atcc 27294  (ATCC)

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

Journal: Small Science

Article Title: Dendritic Cell Vaccine Harboring Inactivated Mycobacteria Induces Immune Protection Against Tuberculosis in Murine Models and is Well Tolerated in Humans

doi: 10.1002/smsc.202400355

Figure Lengend Snippet: Vaccine protective efficacy and Mtb ‐specific recall T‐cell immune responses against Mtb challenge in mice. A) Vaccination, infection, and detection schedule. Mice received blank DCs, DCs loaded with blank macrophage debris (MHDC), BCG, or DCs loaded with debris from BCG‐infected macrophages (BIMHDC) by i.v. injection, and then were challenged with virulent Mtb H37Rv strain 8 weeks later. Five weeks postinfection, the numbers of live bacteria in homogenates of the spleens B) and lungs C) were counted as CFU after 3 weeks of incubation on 7H11 agar and transformed as log 10 ( n = 5, one‐way ANOVA). D) Tissue sections from the right superior lung lobes were stained for histopathology with H&E. Representative histological appearances are shown in (D), show ×200, scale bar = 100 μm. E–K) The recall T‐cell immune responses in the lung cells 5 weeks postinfection. The largest lobe of lung tissue from each mouse in a group was pooled and digested to liberate single lung cells by using collagenase IV and DNase I. The cells were then stimulated with PPD in the presence of monensin and brefeldin A, then analyzed for surface marker expression and intracellular cytokine production by ICS assay. The proportions of CD4 (E) and CD8 (F) T cells producing IFN‐γ, IL‐2, and TNF‐α are shown as histograms ( n = 5, nonpaired t ‐test). The frequencies of the seven cell subpopulations, based on the possible combinations of expression of IFN‐γ, IL‐2, and TNF‐α, are shown for CD4 (G) and CD8 (H) T cells ( n = 5, two‐way ANOVA), and pie chart analysis is shown in (I). The memory phenotypes in CD4 (J) and CD8 (K) T cells are shown ( n = 5, nonpaired t ‐test). T CM and T EM were defined as CD44 + CD62L + and CD44 + CD62L − , respectively. CD4 T RM was defined as CXCR3 + KLRG1 − , and CD8 T RM was defined as CD69 + CD103 + . The results are representative of two independent experiments with five mice per group. Values are expressed as mean ± SEM. * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001, and ns, no significant difference.

Article Snippet: The BCG Danish strain and Mtb H37Rv strain (ATCC 27 294) used in this study were stocked in our laboratory.

Techniques: Infection, Injection, Bacteria, Incubation, Transformation Assay, Staining, Histopathology, Marker, Expressing