Antimicrobial compositions including a cell penetrating peptide (CPP) having the amino acid sequence Tyr-Ala-Arg-Val-Arg-Arg-Arg-Gly-Pro-Arg-Gly-Tyr-Ala-Arg-Val-Arg-Arg-Arg-Gly-Pro-Arg-Arg (SEQ ID NO:1) or variant thereof are disclosed. The CPP, which itself has antimicrobial properties, can be advantageously combined with or conjugated to a cargo to increase the delivery, efficacy, or combinations thereof, of the cargo into cells. In preferred embodiments, the CPP is combined with or conjugated to a functional nucleic acid, such as an external guide sequence (EGS) which can target and reduce expression of essential microbial genes or genes than impart resistance to antimicrobial drugs. Methods of using the compositions alone or in combination with traditional antimicrobial drugs to treat infections are also disclosed.
