Pixantrone Sensitizes Gram-Negative Pathogens to Rifampin

Abstract

Bacterial resistance has become increasingly serious because of the widespread use and abuse of antibiotics. In particular, the emergence of multidrug-resistant bacteria has posed a serious threat to human public health.

Anti-staphylococcal activity of a polyphenol-rich citrus extract: synergy with β-lactams and low proficiency to induce resistance

“…The fractional inhibitory concentration index (FICI) was calculated using the following formula: (MIC of B in combination)/(MIC of B alone) + (MIC of antibiotic in combination)/(MIC of antibiotic alone). The FICI values were interpreted as follows: FICI ≤0.5 indicate synergy, 0.5 < FICI <4 indicate indifference, while values >4 indicate antagonism ( She et al, 2022 ). Three independent biological replicates were performed.…”

Baicalein Resensitizes Multidrug-Resistant Gram-Negative Pathogens to Doxycycline

“…LIVE/DEAD BacLight bacterial viability kits (Molecular Probes) containing SYTO9 and PI were used to distinguish between live and dead bacteria. The samples were visualized using a Zeiss Axio Scope A1 upright microscope, and the images were processed for merging using the ImageJ software ( 46 ).…”

“…Next, the bacterial suspensions were mixed with 10 nmol/L of PI (Solarbio, Beijing, China) to detect the permeabilization of the inner membrane, and then the suspensions were coincubated for 30 min in the dark. The fluorescence was detected at emission/excitation wavelengths of 615/535 nm ( 46 ). In the fluorescence or luminescence assay, the corresponding concentrations of drugs (without cells) were incubated with probes as blank controls, and the relative fluorescence intensity was calculated as the value of the analyte minus the value of the blank control.…”

“…Bacterial suspension with an OD 600 of 0.5 was coincubated with 0.2 × 10 −6 M of 2’,7’-Bis (2-carboxyethyl-5(6)-carboxyfluorescein) (BCECF)-AM (acetoxymethyl ester) or 0.5 × 10 −3 mM of 3,3-dipropylthiadicarbocyanine iodide [DiSC 3 (5); Sigma-Aldrich] for 30 min at 37°C. Then, 10 μL of different drugs, glucose (2.5 × 10 −5 M), or melittin (16 μg/mL) was added as a supplement and incubated for 30 min, and the fluorescence values of PMF and dissipated bacterial ΔΨ were determined by excitation/emission at 500/522 nm and 622/670 nm, respectively ( 46 ).…”

Simeprevir restores the anti-Staphylococcus activity of polymyxins

“…After incubation at 37℃ for 16-18 h, the optical density at 630 nm (OD 630 ) was measured, and the antibacterial interaction between the drugs was calculated by . FICI ≤ 0.5 indicates synergy, 0.5 < FICI ≤ 4 indicates no interaction, and FICI > 4 indicates antagonism (She et al 2022).…”