Isolation, Characterization, and Classification of Three Bacteriophage Isolates for the Genus Levinea

Bacteriophages for the genus Levinea were isolated from sewage samples. On the basis of plaque morphology and host specificity, three different phage isolates were obtained and purified by standard techniques. Cross-neutralization experiments with homologous and heterologous phage antisera showed no serological relatedness among the three phages and, therefore, they were placed into three serological groups. Electron micrographs showed the isolates to have different and distinctive morphological types, one of which was unique in that it possessed an elongated "bullet-shaped" capsid. Nucleic acid types for the three phages were determined by the acridine orange-fluorescent staining technique to be double-stranded deoxyribonucleic acid. Based on serological grouping, the three phages were classified and designated DM-11, DM-21, and DM-31. The value of the phage isolates in defining the species of the genus Levinea is discussed.