الفهرس | Only 14 pages are availabe for public view |
Abstract This study was aimed to isolate and characterize bacteriophages infecting some pathogenic bacteria. The E. coli O157:H7 wild type strain 93111 and B. cereus ATCC 33013 - specific phages were successfully isolated. Four B. cereus phages (BCP₁, BCP₂, BCP₃ and BCP₄) were isolated from clay soil samples, whereas four E. coli phages (ECP₁, ECP₂, ECP₃ and ECP₄) were isolated from sewage and Nile water. The morphological characterization of isolated phages suggests that the phages of infecting B. cereus could be considered as members of Siphoviridae or Myoviridae families. The morphology of E. coli phages confirms their classification to Tectiviridae, Corticoviridae, Siphoviridae or Podoviridae families. The genome size of the isolated B. cereus and E. coli phages ranged between 28.7 - 33.6 kbp and 34.5- 41.5, respectively. The four isolated B. cereus phages exhibited very limited host spectrum, infecting only 2 of 9 Bacillus spp. The ECP₂ has the ability to infect eight strains of Escherichia coli including five strains of shiga toxin producing E. coli and three nontoxigenic E. coli strains. The SDS-PAGE analysis of phage proteins revealed that the BCP₃ and ECP1 had five protein bands with molecular weights ranging from 37.0 to 110.0 and from 34.0 to 112.0 kDa, respectively. The effect of some stress conditions on the BCP1 and ECP2 survivability was evaluated |