Journal: Journal of Biomedical Optics

Article Title: Digital holographic microscopy for rapid bacteria segmentation and counting in microfluidic cartridges: basic considerations and limitations for diagnostic application

doi: 10.1117/1.JBO.30.10.106501

Figure Lengend Snippet: Numerical refocusing and counting results using bacteria. Representative images of videos showing the numerically refocused phase image (a) and segmented structures (b). (a) S. warneri at 200 μ m and 1:3 dilution of an OD 600 = 1 suspension ( Video 3 ); (b) E. coli at 200 μ m and 1:3 dilution of an OD 600 = 1 suspension ( Video 4 ); (c) S. warneri at 400 μ m and 1:10 dilution of an OD 600 = 1 suspension ( Video 5 ); (d) E. coli at 400 μ m and 1:30 dilution of an OD 600 = 1 suspension ( Video 6 ). Refocused phase images and binary images of segmented structures represent identical fields of views for direct comparison, respectively. Green colored scale bars correspond to 10 μ m ; (e) counting results for S. warneri at 200 and 400 μ m chamber height; (f) counting results for E. coli at 200 and 400 μ m chamber height. Dilution factors on the x -axis refer to a bacterial suspension adjusted to OD 600 = 1 . Counting results include at least three biological replicates, each taken at multiple positions within the same microfluidic chamber. The error bars represent one standard deviation of uncertainty; (g) and (h) coefficient of variation (CV) in percent, calculated as the ratio of the standard deviation to the mean particle count from the results shown in panels (e) and (f), respectively ( Video 3 , MP4 [URL: https://doi.org/10.1117/1.JBO.30.10.106501.s3 ], 7.83 MB; Video 4 , MP4, 7.37 MB [URL: https://doi.org/10.1117/1.JBO.30.10.106501.s4 ]; Video 5 , MP4, 12.8 MB [URL: https://doi.org/10.1117/1.JBO.30.10.106501.s5 ]; Video 6 , MP4, 10.8 MB [URL: https://doi.org/10.1117/1.JBO.30.10.106501.s6 ]).

Article Snippet: Bacterial suspensions [rod-shaped Gram-negative Escherichia coli ( E. coli ) strain K12 DH5-alpha (Invitrogen, Karlsruhe, Germany), spherical Gram-positive Staphylococcus warneri ( S. warnri ) strain DSM20316 (DSMZ, Braunschweig, Germany)] were grown overnight during shaking at 37°C in LB-medium ( E. coli ) or TSB-medium ( S. warneri ), respectively.

Techniques: Bacteria, Suspension, Comparison, Standard Deviation

Journal: Journal of Biomedical Optics

Article Title: Digital holographic microscopy for rapid bacteria segmentation and counting in microfluidic cartridges: basic considerations and limitations for diagnostic application

doi: 10.1117/1.JBO.30.10.106501

Figure Lengend Snippet: Evaluation of the DHM system using bacterial suspensions (1:10 dilution of OD 600 = 1 ), green colored scale bars correspond to 10 μ m . Rows (1) to (2) S. warneri and E. coli , respectively, at 200 μ m chamber height and rows (3) to (4) S. warneri and E. coli , respectively, at 400 μ m chamber height. First column (a1–a4): recorded holograms with a magnified view of bacteria 4 to 10 μ m out-of-focus. Please note that in the case of S. warneri , two bacteria are observed to be aligned axially (a1) and transversely (a3); second column (b1–b4): numerically refocused phase images of holograms in column (a1–a4), respectively, with a magnified view at the same position as in (a1–a4); third column (c1–c4): color-coded profile plots along the lines in column (b1–b4).

Article Snippet: Bacterial suspensions [rod-shaped Gram-negative Escherichia coli ( E. coli ) strain K12 DH5-alpha (Invitrogen, Karlsruhe, Germany), spherical Gram-positive Staphylococcus warneri ( S. warnri ) strain DSM20316 (DSMZ, Braunschweig, Germany)] were grown overnight during shaking at 37°C in LB-medium ( E. coli ) or TSB-medium ( S. warneri ), respectively.

Techniques: Bacteria

Journal: Journal of Biomedical Optics

Article Title: Digital holographic microscopy for rapid bacteria segmentation and counting in microfluidic cartridges: basic considerations and limitations for diagnostic application

doi: 10.1117/1.JBO.30.10.106501

Figure Lengend Snippet: (a) Mean phase noise ⟨ ϕ N ⟩ calculated using Eq. (1) for various sample types, concentrations, and chamber heights. Dashed line corresponds to a quadratic interpolation of the values measured for microspheres. Interpolated polynomials are given in the color-coded boxes together with their respective coefficients of determination. The analysis includes three independent dilution series for microspheres and at least three biological replicates for bacteria, each captured at multiple positions within the same microfluidic chamber. The error bars represent one standard deviation of uncertainty. The dilutions 1:2400 and 1:10 for the 400 μ m chamber height were omitted due to technical reasons; (b) mean signal-to-noise ratios for the various sample types, concentrations, and chamber heights. Points correspond to the ratio between the calculated phase signal ⟨ ϕ S ⟩ using Eq. (4) and the measured phase noise ⟨ ϕ N ⟩ using Eq. (1). The lines are the ratio between the calculated phase signal ⟨ ϕ S ⟩ using Eq. (4) and the interpolated phase noise ⟨ ϕ ^ N ⟩ in Eq. (2). MS, microspheres; SW, S. warneri ; EC, E. coli ; mes., measured, and thr., theoretical.

Article Snippet: Bacterial suspensions [rod-shaped Gram-negative Escherichia coli ( E. coli ) strain K12 DH5-alpha (Invitrogen, Karlsruhe, Germany), spherical Gram-positive Staphylococcus warneri ( S. warnri ) strain DSM20316 (DSMZ, Braunschweig, Germany)] were grown overnight during shaking at 37°C in LB-medium ( E. coli ) or TSB-medium ( S. warneri ), respectively.

Techniques: Bacteria, Standard Deviation

Journal: Gut microbes

Article Title: Staphylococcus warneri dampens SUMOylation and promotes intestinal inflammation.

doi: 10.1080/19490976.2024.2446392

Figure Lengend Snippet: Figure 2. S. epidermidis does not inhibit host cell SUMOylation. (a) immunoblot analysis of SUMO2/3-conjugated proteins, SAE1, SAE2 and Ubc9 in HeLa cells treated with dilutions of S. warneri (S. warn) or S. epidermidis (S. epi) supernatants, or with bacterial culture medium alone (BHI), for 5 h. (b) quantification of SUMO2/3-conjugated proteins (above 50 kDa), SAE1, SAE2 and Ubc9 levels after normalization by actin levels. Values are expressed as fold-change versus untreated cells (mean ± s.d.; n = 4; **, P<0.01; ***, P<0.001; NS, not significant; one-way ANOVA, with Dunnett’s correction).

Article Snippet: The bacterial strains used in this study were Staphylococcus warneri AW25 type strain (DSM 20316, DSMZ, Germany), Staphylococcus epidermidis ATCC 14990 type strain (DSM 20044, DSMZ, Germany) and Escherichia coli BL21(DE3)pLysS strain.

Techniques: Western Blot