This invention relates to a peptide selected from the group: FLLDADHNTFGSVIPATGPLFTGTASS
LYSANFESLIPANADPVVTTQNIIVTG LYSANFEYLIPANADPVVTTQNIIVTG TNPEPASGKMWIAGDGGNQP RYDDFTFEAGKKYTFTMRRAGMGDGTD
DDYVFEAGKKYHFLLLMKKMGSGDGTE TNPEPASGKMWIAGDGGNQPARYDDFTFEAGKKYTFTMRRAGMGDGTD NTFGSVIPATGPL
PASGKMWIAGDG EAGKKYTFTMRRA EAGKKYHFLMKKM. It also relates to compositions and use
of these peptides for treating and testing Porphyromonas gingialis.