Use of at least one compound of formula below: in which: - R represents a hydrogen atom; - R 3 represents a hydrogen atom; - R 4 and R 7 repesent a hydrogen atom; - R 5 and R 6 represent independently of each other a group chosen from one of the following groups: * a hydrogen atom; * a alkoxyl group comprising 1 to 7 carbon atoms or a benzyloxyl group; * a halogen atom chosen from Br, Cl, F or I; - R 1 represents a group chosen from one of the following groups: * a -CH 2.NH-GP group, GP representing a group chosen from the following groups: Boc. Cbz, or Me 3 SiCH 2 CH 2 OCO (Teoc); * a -CH 2 -NH 2 or -CH 2 -NH 2.X group, X representing HCl, HCOOH or HOOCCOOH; - R 2 represents a group chosen from one of the following groups: * a hydrogen atom; * an O - group; * an OH group; * an acyl group comprising 1 to 10 carbon atoms; - B represents a group chosen from one of the following groups: * a representing a single bond or a double bond; * A representing N or N +;. a representing a single bond when A represents N;. a representing a double bond when A represents N + and R 2 represents O"; * R', R" and R'" representing, independently of each other, a group chosen from one of the following groups: * a hydrogen atom; * an alkoxyl group comprising 1 to 4 carbon atoms; * R IV representing a hydrogen atom; * GP 1 representing a Boc or Cbz group; * R c representing a hydrogen atom; said compounds of formula being possibly in the form of optical isomers, namely in the form of enantiomers or mixtures of enentiomers, including racemic mixtures, or in the form, if appropriate, of salts of physiologically acceptable acids, for the preparation of a medicament intended for the treatment of pathologies associated with bacterial infections. - R represents a hydrogen atom; - R 3 represents a hydrogen atom; - R 4 and R 7 repesent a hydrogen atom; - R 5 and R 6 represent independently of each other a group chosen from one of the following groups: * a hydrogen atom; * a alkoxyl group comprising 1 to 7 carbon atoms or a benzyloxyl group; * a halogen atom chosen from Br, Cl, F or I; * a hydrogen atom; * a alkoxyl group comprising 1 to 7 carbon atoms or a benzyloxyl group; * a halogen atom chosen from Br, Cl, F or I; - R 1 represents a group chosen from one of the following groups: * a -CH 2.NH-GP group, GP representing a group chosen from the following groups: Boc. Cbz, or Me 3 SiCH 2 CH 2 OCO (Teoc); * a -CH 2 -NH 2 or -CH 2 -NH 2.X group, X representing HCl, HCOOH or HOOCCOOH; * a -CH 2.NH-GP group, GP representing a group chosen from the following groups: Boc. Cbz, or Me 3 SiCH 2 CH 2 OCO (Teoc); * a -CH 2 -NH 2 or -CH 2 -NH 2.X group, X representing HCl, HCOOH or HOOCCOOH; - R 2 represents a group chosen from one of the following groups: * a hydrogen atom; * an O - group; * an OH group; * an acyl group comprising 1 to 10 carbon atoms; * a hydrogen atom; * an O - group; * an OH group; * an acyl group comprising 1 to 10 carbon atoms; - B represents a group chosen from one of the following groups: * a representing a single bond or a double bond; * A representing N or N +;. a representing a single bond when A represents N;. a representing a double bond when A represents N + and R 2 represents O"; * R', R" and R'" representing, independently of each other, a group chosen from one of the following groups: * a hydrogen atom; * an alkoxyl group comprising 1 to 4 carbon atoms; * R IV representing a hydrogen atom; * GP 1 representing a Boc or Cbz group; * R c representing a hydrogen atom; * a representing a single bond or a double bond; * A representing N or N +;. a representing a single bond when A represents N;. a representing a double bond when A represents N + and R 2 represents O";. a representing a single bond when A represents N;. a representing a double bond when A represents N + and R 2 represents O"; * R', R" and R'" representing, independently of each other, a group chosen from one of the following groups: * a hydrogen atom; * an alkoxyl group comprising 1 to 4 carbon atoms; * a hydrogen atom; * an alkoxyl group comprising 1 to 4 carbon atoms; * R IV representing a hydrogen atom; * GP 1 representing a Boc or Cbz group; * R c representing a hydrogen atom;