0×105

cells/well). Culture supernatants were removed and the monolayer was washed once with PBS buffer. Fresh bacterial cells cultured to an OD600 of 1.0 were diluted in DMEM with or without DSF at a final concentration of 50 μM, which were then added to the HeLa cell monolayers at a multiplicity of infection (MOI) about 1000, and gentamycin was added at different final concentrations as indicated. Cytotoxicity was determined by BAY 11-7082 measuring the release of the cytosolic selleckchem enzyme lactate dehydrogenase (LDH) into supernatants using the cytotoxicity detection kit (Roche). Acknowledgements The funding for this work was provided by the Biomedical Research Council, the Agency of Science, Technology and Research (A*Star), Singapore. Electronic supplementary material Additional file 1: Figure S1: Real-time PCR analysis of DSF effect on transcriptional expression of selected genes in B. cereus 10987. Table S1. The genes with increased or decreased expression in B. cereus 10987 after treatment with 50 μM DSF. Figure S2. The bacterial growth rate in the presence and absence of 50 μM DSF or its analogue. Figure S3. Effect of DSF signal and rhamnolipid on the growth rate of B. thuringiensis. Table S2. Bacterial strains used in this study. (DOCX 107 KB) References 1. Livermore DM: The need for new

antibiotics. Clin Microbiol Infect 2004, 10:1–9.PubMedCrossRef 2. Pfaller MA, Jones RN, Doerm GV, Kugler K: Bacterial pathogens isolated from patients with bloodstream infection: frequencies of occurrence Ulixertinib purchase and

antimicrobial Selleckchem AZD9291 susceptibility patterns from the SENTRY antimicrobial surveillance program (United States and Canada, 1997). Antimicrob Agents Chemother 1998, 42:1762–1770.PubMedCentralPubMed 3. Slama TG, Amin A, Brunton SA, File TM Jr, Milkovich G, Rodvold KA, Sahm DF, Varon J, Weiland D Jr: A clinician’s guide to the appropriate and accurate use of antibiotics: the Council for Appropriate and Rational Antibiotic Therapy (CARAT) criteria. Am J Med 2005,118(suppl):1–6.CrossRef 4. Giannini AJ, Black HR: Psychiatric, psychogenic and somatopsychic disorders handbook. Garden City, NY: Medical Examination Publishing Co.; 1987:136–137. 5. Sundin DP, Sandoval R, Molitoris BA: Gentamicin inhibits renal protein and phospholipid metabolism in rats: implications involving intracellular trafficking. J Am Soc Nephrol 2001, 12:114–123.PubMed 6. Aaron SD, Ferris W, Henry DA, Speert DP, Macdonald NE: Multiple combination bactericidal antibiotic testing for patients with cystic fibrosis infected with Burkholderia cepacia . Am J Respir Crit Care Med 2000, 161:1206–1212.PubMedCrossRef 7. Athamna A, Athamna M, Nura A, Shlyakov E, Bast DJ, Farrell D, Rubinstein E: Is in vitro antibiotic combination more effective than single-drug therapy against anthrax? Antimicrob Agents Chemother 2005, 49:1323–1325.PubMedCentralPubMedCrossRef 8.