Fluorinated cephalosporin antibiotics and their use for the treatment of mastitis

The invention provides new fluorinated cephalosporin antibiotics of Formula I wherein R, R, R, R and R, independently, are H, F or C1-C6 alkyl-(Z)n- group having at least one fluorine substituent; X is O or S; Y is S, O, or -CH2-; Z is O, S, -SO-, or -SO2-; m and n independently are 0 or 1; and R is H, C1-C6-alkyl, phenyl or benzyl, each of which may optionally have up to three substituents selected from halo, C1-C4-alkoxy, phenyl, NO2, C1-C6-alkanoyl, benzoyl, or C1-C6-alkanoyloxy; or a physiologically acceptable salt thereof; provided that: 1) at least one of R, R, R, R or R is other than hydrogen; and 2) when R is F, or one of R or R is CF, at least one of the remaining R, R, R, R or R is other than hydrogen, processes for preparing these compounds and veterinary and pharmaceutical formulations containing a Formula I compound as an active ingredient.