Isolation And Identification Of Phage-Host Systems From Xiamen Harbor And Baltic Sea, And Preliminary Study Of Detection Of Stained Host Bacteria By Fluorescent-Labeled Phages

This research is based on the cooperative project "Autochthonous phage-host systems in different aquatic habitats" (HB08302(1)) in the charge of Third Institute of Oceanography, State Oceanic Administration in China and Leibniz Institute for Baltic Sea Research Warnemiinde in Germany.4 samples were collected from coasts of Xiamen Harbor and Baltic Sea.We used the traditional double-layer-agar plating method to isolate autochthonous phage host systems from different habitats. The characterization of isolated host strains were mainly based on sequencing of the 16S rDNA and comparing with sequences of the known species. Phages were mainly characterized by its morphology using TEM and the restriction patterns of its DNA. On the basis of the biological charecteristics of phages, we focused on the primary research and developing the protocols of "Staining of host bacteria by fluorescently labeled phages", and discussed the parameters which are likely to impact the staining processes and effects, in order to accumulate data for discussion of the phage-host interaction and phage therapy to pathogenic bacteria.The results showed that:1.9 phage-host systems were isolated;2.9 host bacteria isolated were identified to belong to y-Proteobacteria and Enterobacteria respectively;3.9 phages isolated belonging to Bradley group B1 and A1; or Siphoviridae and Myoviridae respectively, all in Caudovirales. The combination of phages morphology and restriction analysis by enzyme BglII and EcoRV showed that the phages should be different.4. Based on the biological characteristics of 9 phages, we eventually selected the PHSs:φ2YDI16-2YDI16 andφV2X2-V2X2 to proceed with the experiments of "Staining of host bacteria by fluorescently labeled phages ". The results showed that:using EFM, SYBR Gold labeled FLPs can specifically detect their host bacteria from bacteria mixture.