Could viruses act as a replacement for antibiotics?

In one of my biology lessons today my teacher was talking about a microbiology course he had been on where he had been looking at the growth of bacteria in different conditions. He told my class about an experiment the people on the course with him had conducted involving viruses which attack bacteria called bacteriophages. I was extremely interested in this because straight away it got me thinking about the uses it could have,including as an antibiotic. This is especially important due to the thousands of antibiotic resistant strains of bacteria emerging, making it more difficult to treat patients suffering from diseases such as MRSA. He showed us an agar plate with his bacteria colonies beginning to grow with a wall down the middle. On one side of the wall was just the bacteria (E.coli)and on the other was the bacteria mixed with the bacteriophage. This interested me so much that I decided to do a little bit of research into bacteriophages. 

I discovered that phages, in the environment in general, work by producing enzymes called lysins which destroy the bacteria and therefore release hundreds more of the phages which had been held by the bacteria into the rest of the colony to attack more bacteria cells. 

Bacteriophages can therefore be used as an alternative to antibiotics due to their ability to perform the exact same function; destroying bacteria. This development of bacteriophages into medication as a treatment for bacterial infection would result in huge developments in the medical world. I found some information about an experiment conducted by the laboratory of William Smith which investigated the use of phages of the treatment of E.coli in mice. They wrote a paper which stated that a single dose of a certain E.coli phage was able to greatly reduce the number of that strain of E.coli in the alimentary tract of animals with a diarrhoea causing strain. This resulted in less fluid loss meaning that all of the animals treated with the phage survived.