ISOLATION, CLASSIFICATION AND MOLECULAR CHARACTERIZATION OF BACTERIOPHAGES FOR ENTEROBACTER SPECIES

Out of 22 Enterobacter phages investigated, nine were found to be suit able for phage typing based on their different lytic spectra on 398 st rains of Enterobacter spp. isolated from milk powder and other foods. These phages were compared on the basis of morphology, protein composi tion, restriction endonuclease patterns and DNA-DNA hybridization. Two phages (WS-EP19, WS-EP13) belonged to the Podoviridae family (morphot ype Cl), and three (WS-EP20, WS-EP26, WS-EP28) were classified as Siph oviridae (morphotype B1). The other four phages were Myoviridae of the morphological groups Al (WS-EP57) and A2 (WS-EP32, WS-EP94, WS-EP96). SDS-PAGE revealed individual protein profiles for each phage, which c orresponded to different restriction enzyme fragment patterns. DNA-DNA hybridization demonstrated the close relationship of phages WS-EP20 a nd WS-EP26, and of WS-EP94 and WS-EP96. In general, a good correlation was found between groupings obtained with the various methods. The ni ne phages could be attributed to existing enterobacterial phage specie s although some differences to the described type phages were observed .