A method of inhibiting growth of a bacterium including steps of: a) delivering a polynucleotide including a sequence of SEQ ID NO: 1 or a homologue thereof to the bacterium, and b) contacting the bacterium with an effective amount of an antibiotic; wherein the bacterium is Pseudomonas aeruginosa. A method of treating a subject suffering from an infection caused by a bacterium which is Pseudomonas aeruginosa and the method including steps of: i) delivering said polynucleotide to a tissue infected by the bacterium or a bacterial cell in the subject; and ii) administering an effective amount of an antibiotic to the subject. A composition and a recombinant plasmid containing said polynucleotide.