Therapeutic combination of daptomycin and protein synthesis inhibitor antibiotic, and methods of use

A therapeutic combination comprising

• an antibacterially effective amount of daptomycin, and
• an amount of a compound of Formula (I), or a pharmaceutically acceptable salt thereof, effective to prevent the development of daptomycin non-susceptible bacterial strains
• wherein,
• Het is tetrazolyl or oxadiazolyl;
• ring A is unsubstituted or has at least one fluorine substituent;
• R7 is H, PO(OH)2 or PO(O)2−2(M+)2, wherein M+ is a metal cation;
• R3 is H or unsubstituted C1-4 alkyl group.