PROBLEM TO BE SOLVED: To provide a novel pharmaceutical or sterilization agent, effective for therapy and prevention of bacterial infection caused by multi-drug-resistant Pseudomonas aeruginosa (MDRP), etc.SOLUTION: Provided are: a bacterial efflux pump inhibitor of MexY of Pseudomonas aeruginosa or of a bacterium having high homology with MexY, the bacterial efflux pump inhibitor comprising patulin an antibacterial agent to a bacterium having the efflux pump, the antibacterial agent comprising a combination of patulin and antibacterial drugs which may be a substrate of the efflux pump a method for identifying multi-drug-resistant mechanism of pathogenic Pseudomonas aeruginosa strain, which is characterized by separating Pseudomonas aeruginosa strains from a patient infected by multi-drug-resistant Pseudomonas aeruginosa, respectively/independently and combinationally contacting the strains with patulin and antibacterial drugs which may be a substrate of MexY efflux pump of Pseudomonas aeruginosa, and deciding bacterial strains having synergistically inhibited growth in the case of having combination contact relative to the case of respective and independent contact, as strains having multi-drug-resistance mechanism by hyperfunction of MexY efflux pump and the like.COPYRIGHT: (C)2015,JPO&INPIT【課題】多剤耐性緑膿菌(MDRP)等の細菌感染症の治療及び予防に有効な新規医薬又は除菌薬を提供すること。【解決手段】パツリンを含有してなる、緑膿菌のMexY又はMexYと高い相同性を有する細菌の排出ポンプの阻害剤;パツリンと、該排出ポンプの基質となり得る抗菌薬とを組み合わせてなる、該排出ポンプを有する細菌に対する抗菌剤;多剤耐性緑膿菌に感染した患者から分離した該緑膿菌株に、パツリン及び緑膿菌のMexY排出ポンプの基質となり得る抗菌薬をそれぞれ単独で、並びに併用して接触させ、それぞれを単独で接触させた場合に対して、併用して接触させた場合に、相乗的に生育が阻止された菌株を、MexY排出ポンプの機能亢進による多剤耐性機構を有する菌株であると判定することを特徴とする、病原緑膿菌株の多剤耐性機構の同定方法等が提供される。【選択図】なし
