Journal: Tetrahedron letters

Article Title: Identification of an unexpected shunt pathway product provides new insights into tirandamycin biosynthesis

doi: 10.1016/j.tetlet.2016.11.080

Figure Lengend Snippet: Biological activities of tirandamycin K ( 7 ) and C ( 3 ).

Article Snippet: Finally, the antibacterial activity of 7 against a select group of Gram-negative and Gram-positive strains including the Escherichia coli W3110 TolC disruption mutant strain, the Staphylococcus aureus 8325 NorA disruption mutant strain, the S. aureus ATCC 6538P, and the vancomycin-resistant Enterococci (VRE), was evaluated using 3 as a control.

Techniques: Concentration Assay, Mutagenesis

Journal: Frontiers in Microbiology

Article Title: Rapid Phenotypic Antibiotic Susceptibility Testing of Uropathogens Using Optical Signal Analysis on the Nanowell Slide

doi: 10.3389/fmicb.2018.01530

Figure Lengend Snippet: Characterization of the nwSlide as an AST platform. (A) Photograph of a nwSlide (25 mm × 75 mm) holding 672 nanowells in a 14 × 48 matrix. (B) Side view of one nanowell with dimensions and volume (V) indicated. (C) Growth measured at OD 600 of a wt Escherichia coli laboratory strain (W3110, black) and a strain with mutated fnr gene ( BW25113Δfnr , blue) in a nwSlide. Circa 200 nanowells were recorded for each strain, dashed lines = SD, n = 3. (D) The design of functionalized nwSlides used for nwASTs. The left side offers 24 non-functionalized nanowells each for negative (NEG., medium only) and positive (POS., inoculated medium) controls of bacterial growth. The antibiotics ampicillin (blue, AMP), ciprofloxacin (green, CIP), nitrofurantoin (red, NIT), cefadroxil (purple, CFR), mecillinam (yellow, MEC), and trimethoprim (brown, TMP) are coated and distributed in separate rows. The antibiotic concentration varies from lowest (left) to highest (right) as indicated schematically above the nwSlide. Each antibiotic is represented by seven twofold dilutions. Each concentration includes four nanowells that serve as technical replicates. Antibiotic concentrations in individual experiments are defined in Section “Materials and Methods.” (E) MIC determination of the reference strain E. coli ATCC 25922 from one nwAST functionalized as in (D) . The heatmap shows OD 600 recordings in each of the 216 nanocultures over 12 h at indicated conditions. A color change from yellow (low OD 600 ) to red (high OD 600 ) in one row indicates bacterial growth in the corresponding nanowell. Negative and positive controls include 24 wells each. For each antibiotic, growth pattern of the 28 nanocultures at 7 antibiotic concentrations is shown. The vertical gradient symbol indicates that nanocultures in the upper rows are exposed to the lowest concentration of antibiotics, whereas a gradual increase leaves the lower rows representing nanowells exposed to the highest concentration. Black dots represent the T lag of each nanoculture.

Article Snippet: Strains included in this study were wild type (wt) Escherichia coli laboratory strain W3110 , BW25113 (Δfnr-771::kan) [National BioResource Project (NIG, Japan): E. coli ], and the reference strain E. coli ATCC 25922 (Oxoid, United Kingdom).

Techniques: Concentration Assay

Journal: Frontiers in Microbiology

Article Title: Rapid Phenotypic Antibiotic Susceptibility Testing of Uropathogens Using Optical Signal Analysis on the Nanowell Slide

doi: 10.3389/fmicb.2018.01530

Figure Lengend Snippet: Characterization of the nwSlide as an AST platform. (A) Photograph of a nwSlide (25 mm × 75 mm) holding 672 nanowells in a 14 × 48 matrix. (B) Side view of one nanowell with dimensions and volume (V) indicated. (C) Growth measured at OD 600 of a wt Escherichia coli laboratory strain (W3110, black) and a strain with mutated fnr gene ( BW25113Δfnr , blue) in a nwSlide. Circa 200 nanowells were recorded for each strain, dashed lines = SD, n = 3. (D) The design of functionalized nwSlides used for nwASTs. The left side offers 24 non-functionalized nanowells each for negative (NEG., medium only) and positive (POS., inoculated medium) controls of bacterial growth. The antibiotics ampicillin (blue, AMP), ciprofloxacin (green, CIP), nitrofurantoin (red, NIT), cefadroxil (purple, CFR), mecillinam (yellow, MEC), and trimethoprim (brown, TMP) are coated and distributed in separate rows. The antibiotic concentration varies from lowest (left) to highest (right) as indicated schematically above the nwSlide. Each antibiotic is represented by seven twofold dilutions. Each concentration includes four nanowells that serve as technical replicates. Antibiotic concentrations in individual experiments are defined in Section “Materials and Methods.” (E) MIC determination of the reference strain E. coli ATCC 25922 from one nwAST functionalized as in (D) . The heatmap shows OD 600 recordings in each of the 216 nanocultures over 12 h at indicated conditions. A color change from yellow (low OD 600 ) to red (high OD 600 ) in one row indicates bacterial growth in the corresponding nanowell. Negative and positive controls include 24 wells each. For each antibiotic, growth pattern of the 28 nanocultures at 7 antibiotic concentrations is shown. The vertical gradient symbol indicates that nanocultures in the upper rows are exposed to the lowest concentration of antibiotics, whereas a gradual increase leaves the lower rows representing nanowells exposed to the highest concentration. Black dots represent the T lag of each nanoculture.

Article Snippet: Strains included in this study were wild type (wt) Escherichia coli laboratory strain W3110 , BW25113 (Δfnr-771::kan) [National BioResource Project (NIG, Japan): E. coli ], and the reference strain E. coli ATCC 25922 (Oxoid, United Kingdom).

Techniques: Concentration Assay