The present invention relates to peptide sequences enabling mycobacteria to adhere to host cells (e.g., epithelial cells). More particularly, the invention relates to a mycobacterial heparin-binding haemagglutinin type antigen from M. bovis ECG or M. tuberculosis. The invention also relates to a recombinant peptide sequence enabling mycobacteria to adhere to host cells. The polypeptides can be used to prepare vaccines against mycobacterial infections and for serological diagnosis of mycobacterial infections.