Bacteriophages induced by ciprofloxacin in a Borrelia burgdorferi skin isolate

Two types of tailed bacteriophages were detected by electron microscopy in a Borrelia burgdorferi strain which had been isolated from infected human skin and exposed to the gyrase inhibitor ciprofloxacin. One of these phages displayed an isometric 30 nm head, a neck and a contractile tail 50-64 nm in length with a baseplate, according to an A-1 morphology. The other phage showing a B-1 morphology had a 30 nm isometric head as well and a long non-contractile straight tail 115-130 nm in length without neck and baseplate. Both types of phages could be found together within one plasmolysed spirochetal cell. We conclude that we are dealing with a lysogenic strain of Borrelia burgdorferi carrying at least two different prophages inducible by ciprofloxacin.