We also thank Harold Meekel at the University of North Carolina, Chapel Hill, for his help and technical skills with electron microscopy; and Dr. Ziqiang Guan at the Duke University Lipidomics Center for his expertise with mass spectrometry. Also, thanks to Dr. Ken Kreuzer who provided the T4 D+ phage and was extremely helpful with experimental design involving bacteriophage. This work was supported by NIH/NIAID grants R01AI079068 and R01AI064464. Electronic supplementary material Additional file 1: Figure S1. Mass

spectroscopic analysis of lipid A. Lipid A was purified as described below from Compound C MK318 (A), MK496 (B), MK1248 (ΔyieM derivative of MK496) (C), ETEC (D), and ETEC-R (polymyxin B resistant derivative of ETEC) (E). Samples were applied to normal phase LC/MS and relevant areas of the spectrum are shown. Lipid A samples were prepared as described previously [52]. Normal phase liquid chromatography was performed on an Agilent 1200 Quaternary LC system equipped with an Ascentis Silica HPLC column, 5 μm, 25 cm × 2.1 mm (Sigma-Aldrich, St. Louis, MO). www.selleckchem.com/small-molecule-compound-libraries.html mobile phase A consisted of chloroform/methanol/aqueous ammonium hydroxide (800:195:5, v/v); mobile phase B consisted of chloroform/methanol/water/aqueous ammonium hydroxide (600:340:50:5, v/v);

mobile phase C consisted of chloroform/methanol/water/aqueous ammonium hydroxide (450:450:95:5, v/v). The elution scheme for the column after loading of the sample was as follows: 100% mobile phase A was held constant for 2 min, followed by a linear increase Montelukast Sodium to 100% mobile phase B over 14 min. CYT387 molecular weight The column was then held at 100% mobile phase B for 11 min, followed by a linear change to 100% mobile phase C over 3 min. Finally, the mobile phase was set at 100% C for 3 min. The column was returned to 100% mobile phase A over the course of 0.5 min and then held at 100% mobile phase A for 5 min prior to application of the next sample. The LC flow rate was 300 μL/min. The post-column splitter diverted approximately 10% of the LC effluent into the mass spectrometer, a QSTAR

XL quadrupole time-of-flight tandem mass spectrometer (Applied Biosystem, Foster City, CA). Instrumental settings for negative ion electrospray (ESI) and MS/MS analysis of lipid species were as follows: IS = -4500 V; CUR = 20 psi; GSI = 20 psi; DP = -55 V; and FP = -150 V. The MS/MS analysis used nitrogen as the collision the gas. Each injection consisted of about 0.1% of the total lipid extracted from a 20 mL E. coli culture, typically in 10 μL chloroform/methanol (2:1, v/v). Data analysis was performed using Analyst QS software (Applied Biosystem, Foster City, CA). (n = 3). (JPEG 617 KB) Additional file 2: Figure S2. Growth of untreated WT E. coli is unaffected by the addition of OMVs. Relative survival (% Survival) of antibiotic-free cultures of mid-log WT E. coli cultures supplemented with 4 μg/mL OMVs (2 h, 37°C)(Untreated +OMV) compared with non-supplemented, antibiotic-free cultures (Untreated). (n = 9).