Compounds of the formula I OR2R4R6 PARALLEL ¦+¦¦ H-P-O-CH-C-CH2-N- -(CH2)n-N- -R7 ¦¦¦¦I O( )R1R3R5m IN WHICH R1 stands for hydrogen or methyl, R2, R3, R4, R5 and R6 which may be identical or different, each stands for hydrogen or alkyl radicals of 1 to 4 carbon atoms, R7 stands for an alkyl or alkenyl radical of 8 to 18 carbon atoms, n is an integer of 2 or 3 and m is zero or an integer from 1 to 4, having an excellent action against pathogenic bacteria and protozoans especially against oocyst of coccidia when they are used in mixture with one or several chlorinated hydrocarbons.