Virology Group, Agharkar Research Institute, MACS, G.G. Agarkar Road, Pune-411004, India.
Abstracts of the papers presented at the International Conference of Indian Virological Society on “Emerging and Re-emerging viral Diseases of the Tropics and Subtropics” at Indian Agricultural Research Institute, New Delhi, India, December 11–14, 2007.
Attempts were made to isolate bacteriophages from sewage in Pune, which were lytic for one or more Salmonella species. Around 150 bacteriophages were isolated against Salmonella typhi ‘O’, S. typhi ‘H’, S. paratyphi A, S. paratyphi B, S. typhimurium, S. enteritidis, and S. gallinarum. Electron-microscopy of the bacteriophages showed them to be belonging to the families Myoviridae, Siphoviridae, and Podoviridae. Physicochemical characteristics of the bacteriophages, such as viability at various temperatures and in presence of stabilizer, thermal inactivation kinetics, precipitability with PEG, multiplication of phages in different Salmonella spp., etc., were studied. The bacteriophages were shown to be relatively thermostable up to 62°C.
Bacteriophages of S. typhimurium multiplied in most other Salmonella spp., whereas bacteriophages of other spp. of Salmonella showed restricted cross-reactivity among the Salmonella spp. Bacteriophages purified in potassium-tartrate gradient were used, along with incomplete Freund\’s adjuvant, for raising high-titre antibodies in Wistar rats. These Antisera were used to differentiate the various bacteriophage isolates by neutralization test. A single immune-serum could differentiate a large number of the bacteriophages. One-step growth curves have been obtained for some of the bacteriophages. The physicochemical and immunological properties of the bacteriophages could be an important tool in identification and taxonomy of bacteriophages as well lead to clues to their origin.
