Bacteriophage M: an Incompatibility Group M Plasmid-specific Phage

Abstract
SUMMARY: Phage M was specific for bacterial strains, of various genera, harbouring plasmids of the M incompatibility group. It formed turbid plaques which varied from pin point to more than 2 mm in diameter on all hosts where plaques were detected. The phage had an hexagonal outline with a diameter of 27 nm. It contained RNA but differed from other plasmid-dependent RNA phages in being sensitive to chloroform. It adsorbed along the length of shafts of M pili.