commercially available antibiotic disks  (Laborclin BR)

Journal: Advanced Science

Article Title: Proanthocyanidin Interferes with Intrinsic Antibiotic Resistance Mechanisms of Gram‐Negative Bacteria

doi: 10.1002/advs.201802333

Figure Lengend Snippet: Potentiating interaction of cPAC with antibiotic results in growth inhibition. MICs were determined for the combination of cPAC with each antibiotic in vitro. Fractional inhibitory concentration index (FICI) for each combination are shown for A) E. coli CFT073, B) P. mirabilis HI4320, and C) P. aeruginosa PA14. A FICI of ≤0.5 is indicated by the gray shaded area. TMP: trimethoprim; SMX: sulfamethoxazole; FOS: fosfomycin; NIT: nitrofurantoin; GEN: gentamicin; KAN: kanamycin; TET: tetracycline; AZT: azithromycin.

Article Snippet: Step 1: commercially available TET 30 μg or MIN 30 μg antibiotic disk (Thermo Scientific Oxoid, Fisher Scientific, Canada) was placed on top of the inoculated agar surface and the plate was incubated at 37 °C for 18 h. Custom disks were prepared using sterile blank disks (Thermo Scientific Oxoid, Fisher Scientific, Canada) supplemented with 400 μg glucose or 400 μg cPAC with or without 400 μg glucose and left to dry at room temperature.

Techniques: Inhibition, In Vitro, Concentration Assay

Journal: Advanced Science

Article Title: Proanthocyanidin Interferes with Intrinsic Antibiotic Resistance Mechanisms of Gram‐Negative Bacteria

doi: 10.1002/advs.201802333

Figure Lengend Snippet: Synergistic effect of cPAC with TET for the inhibition of growth re‐activation of antibiotic‐exposed cells and prevention of the evolution of resistance. A) Detection of growth re‐activation of antibiotic‐exposed E. coli CFT073 cells using a modified disk‐diffusion assay. Step 1: a TET antibiotic disk was placed on top of MHB‐II agar. The dashed lines mark the diameter of the clear zone surrounding the TET disk. Step 2: the TET disks are replaced with a glucose alone, cPAC+glucose, or cPAC alone disk on the MHB‐II agar plate. The diameter of the clear zone (CZ) and no colony formation inside the clear zone surrounding the cPAC+glucose disk indicate no re‐activation of antibiotic‐exposed cells after disk replacement at Step 2 and colonies inside the inhibition zone (indicated by black arrow) surrounding the glucose disk indicate re‐activation of antibiotic‐exposed cells. The cPAC‐only disk prevented re‐activation of growth, most likely because of synergy with TET remnants. The images shown are only representative images of three independent experiments. Disk diameter: 6 mm. Emergence of antibiotic resistance in B) E. coli CFT073 and C) P. aeruginosa PA14 during 21 serial passages in the presence of sub‐MIC levels of TET compared to 400 µg mL −1 cPAC alone or its combination with 100 µg mL −1 cPAC.

Article Snippet: Step 1: commercially available TET 30 μg or MIN 30 μg antibiotic disk (Thermo Scientific Oxoid, Fisher Scientific, Canada) was placed on top of the inoculated agar surface and the plate was incubated at 37 °C for 18 h. Custom disks were prepared using sterile blank disks (Thermo Scientific Oxoid, Fisher Scientific, Canada) supplemented with 400 μg glucose or 400 μg cPAC with or without 400 μg glucose and left to dry at room temperature.

Techniques: Inhibition, Activation Assay, Modification, Diffusion-based Assay

Journal: Advanced Science

Article Title: Proanthocyanidin Interferes with Intrinsic Antibiotic Resistance Mechanisms of Gram‐Negative Bacteria

doi: 10.1002/advs.201802333

Figure Lengend Snippet: Mechanisms of antibiotic potentiation by cPAC. cPAC‐mediated NPN uptake in A) E. coli CFT073, B) P. mirabilis HI4320, and C) P. aeruginosa PA14. Bacterial cells were pretreated with cPAC or gentamicin (Gen) for NPN uptake. Control represents NPN fluorescence in the presence of only cPAC without bacteria. Inhibition of multidrug efflux pump by cPAC or the known efflux pump inhibitor CCCP in D) E. coli CFT073, E) P. mirabilis HI4320, and F) P. aeruginosa PA14. Control represents untreated bacteria. G) MICs were determined for the combination of cPAC with TET in vitro. FICI values for cPAC+TET combination are shown for efflux pump mutants of P. aeruginosa PA14: mexL − (overexpressing MexJK‐OprM), nfxB − (overexpressing MexCD‐OprJ), nfxC − (overexpressing MexEF‐OprN), nalC − (overexpressing MexAB‐OprM), mexA − (nonfunctioning MexAB‐OprM), and oprM − (nonfunctioning MexAB‐OprM, MexJK‐OprM, and MexXY‐OprM). A FICI index of ≤0.5 is indicated by the gray shaded area. H) Effect of cPAC on cell membrane integrity. Cells of each strain were pretreated separately with cPAC or the cell membrane disrupting agent CTAB. The ratio of green to red fluorescence was normalized to that of the untreated control and expressed as a percentage of the control. All assays were repeated independently three times (* P < 0.05; Student's t‐ test).

Article Snippet: Step 1: commercially available TET 30 μg or MIN 30 μg antibiotic disk (Thermo Scientific Oxoid, Fisher Scientific, Canada) was placed on top of the inoculated agar surface and the plate was incubated at 37 °C for 18 h. Custom disks were prepared using sterile blank disks (Thermo Scientific Oxoid, Fisher Scientific, Canada) supplemented with 400 μg glucose or 400 μg cPAC with or without 400 μg glucose and left to dry at room temperature.

Techniques: Control, Fluorescence, Bacteria, Inhibition, In Vitro, Membrane

Journal: BMC Microbiology

Article Title: Phenotypic and genotypic screening of multidrug resistant Klebsiella pneumoniae isolated from ready to eat street food in Tanta, Egypt

doi: 10.1186/s12866-025-03769-z

Figure Lengend Snippet: Antibiotic profile of K. pneumoniae isolates to tested antibiotics

Article Snippet: In this study, a panel of 16 different commercially available antibiotic disks (HiMedia, India) was used.

Techniques: