Each assay was performed in quadruplicate and repeated three times. The results were converted to percentages of the control (cells only treated with 1% DMSO) and CC50 (concentrations that produce a 50% cytotoxiCity

effect on Vero cell) was calculated by using the SPSS 11.0 software. In vivo assays Male and female BALB/c mice, aged 6–8 weeks (approx. 18–20 g), were used to evaluate the in vivo effects of the compounds. Briefly, these mice were randomly assigned to 8 groups (10-12 per group, half in each sex): 6 compound-treated groups, one negative control and one positive control. All the mice were administrated with 100 μl suspended S. pneumoniae strain ATCC 7466 (5 × 103 CFU/ml in phosphate buffered saline) by Trichostatin A solubility dmso intraperitoneal injection route. selleck products Compounds (1–6) were diluted to the concentration of MIC respectively (1.27 mg/kg/d, 0.65 mg/kg/d, 1.13 mg/kg/d, 2.32 mg/kg/d, 1.27 mg/kg/d, 0.014 mg/kg/d, respectively) with normal sodium and 200 μl was administered by vena caudalis route after selleck chemical infection. Two control groups were administered with 200 μl normal sodium (negative

control) and penicillin (0.42 mg/kg/d, positive control) respectively by the same injection route. Treatments were continued 3 times a day for 3 consecutive days, and these levels of chemicals caused few toxic influences on normal mice. The results are expressed as cumulative survival rates over the following 8-day observation. Acknowledgements This work was supported by the National Natural Science Foundation of China (No. 30671868, 20721003). References 1. Bruyn GA, van Furth

R: Pneumococcal polysaccharide vaccines: indications, efficacy and recommendations. Eur J Clin Microbiol Infect Dis 1991,10(11):897–910.CrossRefPubMed 2. Ryan MW, Antonelli PJ: Pneumococcal antibiotic resistance and rates of meningitis in children. Laryngoscope 2000,110(6):961–964.CrossRefPubMed 3. Cutts FT, Zaman SM, Enwere G, Jaffar S, Levine OS, Okoko JB, Oluwalana C, Vaughan A, Obaro SK, next Leach A, et al.: Efficacy of nine-valent pneumococcal conjugate vaccine against pneumonia and invasive pneumococcal disease in The Gambia: randomised, double-blind, placebo-controlled trial. Lancet 2005,365(9465):1139–1146.CrossRefPubMed 4. Swiatlo E, Champlin FR, Holman SC, Wilson WW, Watt JM: Contribution of choline-binding proteins to cell surface properties of Streptococcus pneumoniae. Infect Immun 2002,70(1):412–415.CrossRefPubMed 5. Sandgren A, Albiger B, Orihuela CJ, Tuomanen E, Normark S, Henriques-Normark B: Virulence in mice of pneumococcal clonal types with known invasive disease potential in humans. J Infect Dis 2005,192(5):791–800.CrossRefPubMed 6. Liang X, Ji Y: Comparative analysis of staphylococcal adhesion and internalization by epithelial cells. Methods Mol Biol 2007, 391:145–151.CrossRefPubMed 7.