Disclosed are a novel pyridine thio derivative, and a pharmaceutical composition using the novel pyridine thio derivative, particularly a pharmaceutical composition having selective antibacterial activity against Helicobacter pylori.Specifically disclosed is a pyridine thio derivative represented by general formula (I) (wherein R and R each represents a hydrogen atom, a C alkyl group or the like； R and R each represents a hydrogen atom, a C alkyl group or the like； X represents -O-, -S- or the like； Y represents a C alkyl group which may be substituted by a substituent or -(R-O)-R (wherein R represents a C alkylene group； R represents a C alkyl group which may be substituted by a substituent, and n represents an integer of 1-10)； and Z represents a hydrogen atom or the like), or a pharmacologically acceptable salt thereof. Also specifically disclosed is a pharmaceutical composition containing the pyridine thio derivative or a salt thereof.
