312. The persistence and recovery of bacteriophage in cheese

Several cheese made from milk after the starter had failed, or during outbreaks of ‘slowness’ at three different places, were found to contain bacteriophage, which it is now possible to isolate from cheese where the whey is no longer available. The concentration of phage in cheese was found to be fairly constant when tested periodically during one year. The significance of such persistence on phage dispersal, its reintroduction into the dairy, and carry-over from one season to the next is pointed out.