Isolation of a Polyvalent Bacteriophage for Escherichia coli, Klebsiella pneumoniae , and Aerobacter aerogenes

Abstract

A lytic bacteriophage isolated from sewage was found to attack strains of Aerobacter aerogenes, Escherichia coli , and Klebsiella pneumoniae , but not members of the genera Salmonella, Proteus , and Serratia. The phage, designated φmp, contained deoxyribonucleic acid with a 50% guanine plus cytosine ratio and a molecular weight of 23.1 × 10 6 daltons. Single-step growth experiments of φmp plated at 37 C on A. aerogenes A2 gave a mean latent period of 20 min, an average burst size of 103 plaque-forming units/infected cell, and an average adsorption rate constant of 3 × 10 −10 ml/min. Electron microscopy of φmp revealed a phage with a flexible tail (165 nm long and 6 nm wide). The phage head had a hexagonal outline (62 nm in diameter).