Abstract: The present disclosure describes Cephem compounds of the formula: wherein, X is N, CH or C—Cl; T is S or the like; A and G are lower alkylene or the like; B is a single bond or the like; D is optionally present, and when present is, —NR7—, —CO—, —CO—NR7—, —NR7—CO—, —NR7—CO—NR7—, or the like; F is optionally present, and when present is or phenylene; R3 and R4 are —OR8; R5 and R6 each is independently hydrogen, halogen, nitrile, or —OR8; or an ester at the carboxyl at the 7-position side chain or at the 4-position, a compound protected at the amino on the ring in the 7-side chain, a pharmaceutically acceptable salt, or a solvate thereof, which have a wide antimicrobial spectrum and have potent antimicrobial activity against beta-lactamase producing Gram negative bacteria.

Abstract: The present invention provides Cephem compounds which have a wide antimicrobial spectrum and have potent antimicrobial activity against beta-lactamase producing Gram negative bacteria as follows: A compound of the formula: wherein, X is N, CH or C—Cl; T is S or the like; A and G are lower alkylene or the like; B is a single bond or the like; D is a single bond, —NR7—, —CO—, —CO—NR7—, —NR7—CO—, —NR7—CO—NR7—, or the like; E is optionally substituted lower alkylene; F is a single bond or optionally substituted phenylene; R3, R4, R5 and R6 each is independently hydrogen, halogene, nitrile, or the like; or an ester, a compound protected at the amino on the ring in the 7-side chain, a pharmaceutically acceptable salt, or a solvate thereof.