The present invention relates in its broadest aspect to combined phage/antibiotic therapy. More particularly, it relates to use of (i) one or more bacteriophages and (ii) one or more antibiotics in the manufacture of a combined product for simultaneous, separate or sequential administration of (i) and (ii) to treat a bacterial infection characterized by biofilm formation, for example an infection comprising or consisting of P. aeruginosa. Treatment in this context may be either therapeutic or prophylactic treatment. Also provided are deposited bacteriophages each exhibiting different strain specificity against P. aeruginosa and combinations of such bacteriophages, e.g. a panel of six deposited bacteriophages which was found to be effective against a high percentage of clinical isolates of P. aeruginosa from canine ear infections.