Bacitracin sensing and resistance in Staphylococcus aureus

Authors

  • Yuuma Yoshida,

    1. Department of Oral Microbiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
    2. Department of Oral and Maxillofacial Surgery, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
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  • Miki Matsuo,

    1. Department of Oral Microbiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
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  • Yuichi Oogai,

    1. Department of Oral Microbiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
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  • Fuminori Kato,

    1. Department of Bacteriology, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima, Japan
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  • Norifumi Nakamura,

    1. Department of Oral and Maxillofacial Surgery, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
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  • Motoyuki Sugai,

    1. Department of Bacteriology, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima, Japan
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  • Hitoshi Komatsuzawa

    1. Department of Oral Microbiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
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  • Editor: Roger Buxton

Correspondence: Hitoshi Komatsuzawa, Department of Oral Microbiology, Kagoshima University Graduate School of Medical and Dental Sciences, Sakuragaoka 8-35-1, Kagoshima City, Kagoshima 890-8544, Japan. Tel.: +81 99 275 6150; fax: +81 99 275 6158; e-mail: hkomatsu@dent.kagoshima-u.ac.jp

Abstract

Bacterial two-component systems (TCSs) have been demonstrated to be associated with not only the expression of virulence factors, but also the susceptibility to antibacterial agents. In Staphylococcus aureus, 16 types of TCSs have been identified. We previously found that the inactivation of one uncharacterized TCS (designated as BceRS, MW gene ID: MW2545-2544) resulted in an increase in susceptibility to bacitracin. In this study, we focused on this TCS and tried to identify the TCS-controlled factors affecting the susceptibility to bacitracin. We found that two ABC transporters were associated with the susceptibility to bacitracin. One transporter designated as BceAB (MW2543-2542) is downstream of this TCS, while another (formerly designated as VraDE: MW2620-2621) is separate from this TCS. Both transporters showed homology with several bacitracin-resistance factors in Gram-positive bacteria. Inactivation of each of these two transporters increased the susceptibility to bacitracin. Expressions of these transporters were significantly increased by the addition of bacitracin, while this induction was not observed in the TCS-inactivated mutant. These results indicate that this TCS senses bacitracin, and also positively regulates the expression of two ABC transporters.

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