Prasad Y.,Mjp Rohilkhand University |
Arpana,Mjp Rohilkhand University |
Kumar D.,Mjp Rohilkhand University |
Sharma A.K.,Mjp Rohilkhand University
Journal of Environmental Biology | Year: 2011
This investigation was aimed to find out appropriate strategy against antibiotic resistant bacterial fish pathogen, F. columnare. This pathogen was found persistently associated with fishes causing columnaris disease and ensuing mass mortality in hatchery and culture system of Sub - Himalayan region. Nine lytic F. columnare phages (FCP1 - FCP9) specific to its fifteen isolates were isolated from the water and bottom sediments of various geo-climatic regions of North India. The F. columnare phage FCP1 (made of hexagonal head and non contractile long tail belonging to family Podovariedae, a member of DNA virus) exhibited broader host range to lyse 9 out of 15 isolates of F. columnare. Therapeutic ability of FCP1 phage was assessed in C. batrachus inoculated intramuscularly (im) with virulent bacterial isolate FC8 and post inoculated (Pl) with FCP1phage (@ 108:106:: cfu : pfu) through intramuscular (im), immersion (bath) and oral (phage impregnated feed) treatment. Significant (p<0.001 ) reduction (less than 10-3 cfu ml1) in host bacterium in the sera, gill, liver and kidney of challenged fishes was noted after 6 hr of phage treatment. Quantum of phage played a significant role in bringing down bacterial population as in the sera of dosel (0 4.55×106PfUml-1) anddose2(@9. 15×106pfu ml-1) treated fishes mean log 10cfu value reduced by 3 logs (58.39%) and 5 logs (73.77%) at 96 hr, respectively. Phage treatment led to disappearance of gross symptoms, negative bacteriological test, detectable phage and 100% survival in experimentally infected C. batrachus. Result of this study provides evidence of profound lytic impact of FCP1 phage and represents its interesting therapeutic importance against antibiotic resistant F. columnare. © 2011 Triveni Enterprises Vikas Nagar, Lucknow, INDIA.