Antibacterial and anti-biofilm activity of the lipid extract from Mantidis ootheca on Pseudomonas aeruginosa / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

The aim of this study is to assess the antibacterial and anti-biofilm properties of the lipid extract from Mantidis ootheca against the gentamycin resistant Pseudomonas aeruginosa. The chemical composition of the lipid extract and its relative proportion were determined using the technique of gas chromatography coupled with mass spectrometry (GC-MS). Antibacterial susceptibility tests were performed using a disc diffusion assay and the minimum inhibition concentration (MIC) was determined by way of the agar dilution method. The anti-biofilm test was carried out with crystal violet staining and scanning electron microscopy (SEM). There were 16 compounds detected, and the most abundant components were sesquiterpenoids, monoterpenes, and trace aromatic compounds. The MIC for P. aeruginosa was 4 mg/ml and the eradication effect on preformed biofilms was established and compared with a ciprofloxacin control. The results of our study indicated that a lipid extract from M. ootheca could be used as a topical and antibacterial agent with anti-biofilm activity in the future.

Evaluation of a lipid extract surfactant isolated from foam from adult sheep lung lavage

A simple and inexpensive method of isolating surfactant was devised. The in vivo function of surfactant isolated from saline alveolar washes of adult sheep lungs by foam formation using nitrogen gas was evaluated. The foam was organic solvent extracted with chloroform:methanol:saline (2:1:1 v/v) either once or twice. Part of each lipid extract surfactant (LES) was autoclaved. The total phosphorus (TP) and saturated phosphatidylcholine (sat PC) measurements were used to quantify these phospholipids in the LES. The mean sat PC:TP ratio was 0.54 and there were no changes with sterilization. to evaluate in vivo function, surfactant deficient preterm rabbits were treated intratracheally with either 100 mg/kg of the isolated sheep surfactant extracted twice with chloroform:methanol (LES-2), surfactant extracted only once (LES- 1), 4 ml/kg Survanta (S), or air (control, Cx). The rabbits were then ventilated with dital volumes of 8 ml/kg and 3 cm H20 positive and expiratory pressure (PEEP). Ventilation pressures (peak inspiratory pressure-PIP in cm H20, mean +/- SE) of animals treated with LES-2 (14.4 +/- 0.7) were lower (p 0.01) than Cx (22.8 + 0.5) and LES-1 (19.5 + 0.6), and not different from S (14.6 +/- 1.1). Dynamic compliances (ml/cmH20/kg) in animals treated with LES-2 (0.6 +/- 0.0) were higher (p 0.01) than Cx (0.4 +/- 0.0) and LES-1 (0.4 +/- 0.0), and not different from S (0.6 +/- 0.1). The initial inflation pressure from pressure-volume curve measurements was lowest for LES-2 treated animals (p0.01 at 20cm H20). Survanta and LES-2 treated animals retained more volume on deflation than Cx and LES-1 animals (p 0.01 at 0 cm H20). The ventilation and pressure-volume curve measurements for the autoclaved LES and non-autoclaved LES were similar. Based on the invivo performance of the LES, recommendations are made for improvements of the isolation procedure. (Author)