The viability was presented in percentage compared with the CFU of the sample without being exposed to stress. Antimicrobial susceptibility tests Minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) of erythromycin, cefotaxime,

gentamicin, polymyxin B, rifampicin and ampicillin were determined by a microtitre broth dilution method as described previously [49, 50]. Acknowledgements We thank Dr. Qijing Zhang (Iowa State University, USA) for providing C. jejuni 81-176. This work was supported by the grant (A09058009010000100) to SR from the Korean Health Technology R&D Project, the Ministry for Health, Welfare and Family Affairs, Republic of Korea. Sunyoung Hwang is a recipient of the graduate fellowship provided by the Ministry of Education through the Brain Korea 21

Project. Electronic supplementary Aloxistatin supplier material Additional file 1: Figure S1. Loss of motility in the rpoN mutant. The diameter of each motility zone was measured after 36 hr incubation of C. jejuni strains on 0.4% motility agar plates at 42°C. (TIFF 177 KB) Additional file 2: Figure S2. Effect of the rpoN mutation on C. jejuni ‘s resistance to alkali, heat and cold stresses. (A) Resistance to alkali stress. The growth under different pHs was examined by dotting 10 μl of serially-diluted bacterial cultures. pH 7 MLN0128 in vitro was used as a control. (B) Heat and cold resistance. Bacteria were exposed to 55°C and -20°C. After exposure, the viability changes were measured by dotting 10 μl of bacterial cultures on MH agar plates. (TIFF 291 KB) Additional file 3: Table S1. Antimicrobial susceptibility of the rpoN mutant. (DOCX 23 KB) References 1. Ruiz-Palacios GM: The health burden of Campylobacter infection and the impact of antimicrobial resistance: playing chicken. Clin Infect Dis 2007,44(5):701–703.PubMedCrossRef 2. Gillespie IA, O’Brien SJ, Penman

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