Proteomic and Electron Microscopy Study of Bacteriophages

Abstract Bacteriophages are one of the key factors playing an important role in exchange of genetic information between different bacterial species leading towards bacterial evolution. Their study becomes especially significant if bacteriophages contribute to the development of new human pathogens. In the present study we have investigated the occurrence of bacteriophages in Bartonella, a genus of Gram-negative bacteria representing facultative intracellular parasites causing strong infections mainly in immune-compromised patients. Proteomic and morphologic characterization of bacteriophage preparations from B.henselae and B.grahamii bacteriophages indicated the presence of three different types of bacteriophages. Bacteriophage-like particles with diameter 42 nm, non-enveloped tailed bacteriophages and large enveloped phages with icosahedral to round cores were identified. Most of the results of our observations suggests, that B.henselae is the host of tailed dsDNA bacteriophages belonging to order Caudovirales and family Myoviridae (similar to bacteriophage P2), and enveloped bacteriophages similar to dsRNA viruses from family Cystoviridae. Small size bacteriophage-like particles could correspond to defective or satellite phages. Similar conclusions might be drawn for B. grahamii, though less experimental evidences are available