new endolysin. The present invention relates to an endolysin activity polypeptide comprising an amino acid sequence according to sequence. 1 and fragments or derivatives thereof, or fusion proteins derived therefrom. Additionally, the present invention relates to nucleic acid molecules encoding said polypeptide or fusion protein, vectors comprising said nucleic acid molecules and host cells comprising either said nucleic acid molecules or said vectors. furthermore, the present invention relates to said polypeptide, fragment, derivative or fusion protein for use as a medicament, in particular for the treatment or prevention of gram-negative bacterial infections, as a diagnostic means, as a cosmetic substance or as a sanitizing agent. . The present invention also relates to the use of said polypeptide, fragment, derivative or fusion protein for the treatment or prevention of gram-negative bacterial contamination of food products, food processing equipment, food processing facilities, surfaces. contacting food products, medical devices, hospital surfaces and surgeries. Additionally, the present invention relates to a pharmaceutical composition comprising said polypeptide, fragment, derivative or fusion protein.nova endolisina. a presente invenção se refere a um polipeptídeo com atividade de endolisina compreendendo uma sequência de amino ácido de acordo com seq id no. 1 e fragmentos ou derivados da mesma, ou proteínas de fusão derivadas da mesma. adicionalmente, a presente invenção se refere a moléculas de ácido nucleico que codificam o referido polipeptídeo ou proteína de fusão, vetores compreendendo as referidas moléculas de ácido nucleico e células hospedeiras compreendendo ou as referidas moléculas de ácido nucleico ou os referidos vetores. adicionalmente, a presente invenção se refere ao referido polipeptídeo, fragmento, derivado ou proteína de fusão para uso como um medicamento, em particular para o tratamento ou prevenção de infecções bacterianas gram-negativas,
