The present invention relates in one aspect to a conjugate of a mucopolysaccharide or mucopolysaccharidic fraction and a cellular wall fragment of a bacterium belonging to the Corynebacterium genus, and in particular to the Corynebacterium granulosum species, also named P40. The conjugate of the invention is applied to medicine, in particular for topical treatment of infections, dermatological affections, such as psoriasis, acne, allergic reactions, such as rashes and eczema, and in vaginal mucosae affections.