Impact of psm-mec in the mobile genetic element on the clinical characteristics and outcome of SCCmec-II methicillin-resistant Staphylococcus aureus bacteraemia in Japan  T. Aoyagi, C. Kaito, K. Sekimizu, Y. Omae, Y. Saito, H. Mao, S. Inomata, M. Hatta, S. Endo, H. Kanamori, Y. Gu, K. Tokuda, H. Yano, M. Kitagawa, M. Kaku  Clinical Microbiology and Infection  Volume 20, Issue 9, Pages 912-919 (September 2014) DOI: 10.1111/1469-0691.12575 Copyright © 2013 European Society of Clinical Infectious Diseases Terms and Conditions

FIG. 1 Nucleotide sequence of the psm-mec open reading frame (ORF) in SCCmec-II. The nucleotide sequence of the psm-mec ORF and its promoter is shown [8, 30]. The psm-mec ORF (grey) is encoded from left to right. Black bold nucleotide A indicates the transcription start site (+1) of the psm-mec ORF. Underlined nucleotides (TATACT) indicate the −10 region of the psm-mec promoter; a −7T>C point mutation in the promoter region was found in this study. Clinical Microbiology and Infection 2014 20, 912-919DOI: (10.1111/1469-0691.12575) Copyright © 2013 European Society of Clinical Infectious Diseases Terms and Conditions

FIG. 2 Mutation of the psm-mec promoter in SCCmec-II MRSA strains increases the amount of extracellular PSMs and decreases biofilm formation. The amount of PSMα1 + Hld (a) and PSMα3 (b) in each clinically isolated MRSA strain (psm-mec-absent MRSA (n = 1), mutated psm-mec promoter MRSA (n = 10), wild-type psm-mec promoter MRSA (n = 41)) was measured by HPLC. (c) Biofilm formation of each MRSA strain onto polystyrene microplates was examined. (a–c) Mean ± standard deviation (SD) from three independent experiments is presented. Statistical analysis was performed using the Mann-Whitney test. (d) Cell extra production of MRSA culture was subjected to western blotting by anti-AgrA IgG and band intensities of AgrA were measured. Data analysis was presented to calculate the relative ratio against AgrA expression of wild-type psm-mec promoter MRSA. Means and SD from three independent experiments are presented. Statistical analysis was performed using the Student t-test. Clinical Microbiology and Infection 2014 20, 912-919DOI: (10.1111/1469-0691.12575) Copyright © 2013 European Society of Clinical Infectious Diseases Terms and Conditions

FIG. 3 MIC values of vancomycin and teicoplanin in SCCmec-II MRSA strains. Vancomycin and teicoplanin MIC values for SCCmec-II MRSA strains (mutated psm-mec promoter MRSA (n = 10), wild-type psm-mec promoter MRSA (n = 41)) were evaluated by the E-test. Clinical Microbiology and Infection 2014 20, 912-919DOI: (10.1111/1469-0691.12575) Copyright © 2013 European Society of Clinical Infectious Diseases Terms and Conditions