In vivo mouse model To evaluate the contribution of EndoS to GAS virulence in vivo, we utilized a murine model of systemic infection. GAS strains were grown as described and resuspended in PBS with 5% mucin for an inoculum of 2 × 107 cfu for WT M1T1

strain 5448 and isogenic mutant 5448ΔndoS, and 5 × 108 cfu for NZ131[empty vector] and NZ131[pNdoS]. 8-10 week old female CD-1 mice (n = 6 for 5448, SC79 solubility dmso n = 10 for NZ131) were infected intraperitoneally with GAS strains and mortality was monitored daily for 10 days. Statistical analysis Cfu enumeration in neutrophil and monocyte killing assays were statistically analyzed by unpaired Student’s t-test. Differences were considered significant if P < 0.05. The in vivo results were evaluated with log-rank (Mantel-Cox) test for comparison of survival curves. Differences in survival were considered significant if P < 0.05. All statistical analysis was performed using GraphPad Prism v.5 (GraphPad Software). Ethical approval Permission

to collect human blood under informed consent was approved by the UCSD Human Research Protections Program. All animal use and procedures were approved by the UCSD Institutional Animal Care and Use Committee. Acknowledgements and Funding AH was supported by a Department of Employment Sciences and Technology (Australia) International Science Linkages grant to Prof. Mark Walker (U. Queensland) and VN. Additional support was provided by the Swedish Research Council (projects 2005-4791 Quisinostat research buy and 2010-57X-20240 to MC), the ACY-738 order Foundations of Crafoord (MC), Bergvall (MC), Österlund (MC), Wiberg (MC), Söderberg (MC), Kock (MC) the Swedish Society for Medicine (MC), the Royal Physiografic Society (MC), King Gustaf V’s Memorial Fund (MC), and Hansa Medical AB (MC). CYMO is a San Diego IRACDA Postdoctoral Fellow supported by NIH Grant

GM06852. Electronic supplementary material Additional file 1: Table S1. (PDF 110 KB) References 1. Cunningham MW: Pathogenesis of group A streptococcal infections. Clin Microbiol Rev 2000,13(3):470–511.PubMedCrossRef 2. Carapetis JR, Steer AC, Mulholland EK, Weber M: The global burden of group A streptococcal diseases. GPX6 Lancet Infect Dis 2005,5(11):685–694.PubMedCrossRef 3. Kwinn LA, Nizet V: How group A Streptococcus circumvents host phagocyte defenses. Future Microbiol 2007, 2:75–84.PubMedCrossRef 4. Collin M, Olsén A: EndoS, a novel secreted protein from Streptococcus pyogenes with endoglycosidase activity on human IgG. EMBO J 2001,20(12):3046–3055.PubMedCrossRef 5. Nose M, Wigzell H: Biological significance of carbohydrate chains on monoclonal antibodies. Proc Natl Acad Sci USA 1983,80(21):6632–6636.PubMedCrossRef 6. Krapp S, Mimura Y, Jefferis R, Huber R, Sondermann P: Structural analysis of human IgG-Fc glycoforms reveals a correlation between glycosylation and structural integrity. J Mol Biol 2003,325(5):979–989.PubMedCrossRef 7.