PROBLEM TO BE SOLVED: To provide a cephem compound having a wide antibacterial spectrum and especially exhibiting strong antibacterial activities against β-lactamase producing Gram-negative bacteria and to provide a pharmaceutical composition comprising the same.SOLUTION: There is provided a cephem compound represented by the formula (I), an ester of a carboxyl group, a protected product in an amino group when the amino group is present on the ring in the 7-position side chain or a pharmaceutically acceptable salt thereof. (R1 represents a substituted/unsubstituted heterocyclic group or the like R2A and R2B together represent substituted/unsubstituted hydroxyimino or the like R3 represents H, -OCH3 or the like and R5A and R5B each independently represents H, a lower alkyl or the like.)SELECTED DRAWING: NoneCOPYRIGHT: (C)2016,JPO&INPIT【課題】広範な抗菌スペクトルを有し、特にβ-ラクタマーゼ産生グラム陰性菌に対し強い抗菌活性を示すセファム化合物およびそれを含有する医薬組成物の提供。【解決手段】式(I)で表されるセフェム化合物、カルボキシのエステル体、もしくは7位側鎖の環上にアミノ基が存在する場合の該アミノ基における保護体又はそれらの製薬上許容される塩。(R1は置換/非置換の複素環式基等;R2A及びR2Bは一緒になって置換/非置換のヒドロキシイミノ等;R3はH、-OCH3等;R5A及びR5Bは各々独立にH又は低級アルキル等)【選択図】なし
