Molecular characterization of Vibrio harveyi bacteriophages isolated from aquaculture environments along the coast of India

Abstract

Seven bacteriophages specific to Vibrio harveyi, the causative agent of luminous vibriosis in shrimp, were isolated from coastal aquaculture systems like shrimp farms, hatcheries and tidal creeks along the east and west coast of India. All the seven phages were found to have the typical head and tail morphology with double-stranded DNA as genetic material. Morphologically, six phages were grouped under family Siphoviridae and one under Myoviridae. These phages were further characterized with respect to host range, morphology and structural proteins. Genomic fingerprinting was carried out using restriction fragment length polymorphism (RFLP) and randomly amplified polymorphic DNA (RAPD). Major capsid proteins of all the phages detected by SDS-PAGE were distinct from one another. All the phages were found to be highly lytic for V. harveyi and had different lytic spectrum for the large number of isolates tested. Six of the seven phages isolated had a broad lytic spectrum and could be potential candidates for biocontrol of V. harveyi in aquaculture systems.

New Approach to Use Phage Therapy against Aeromonas hydrophila Induced Motile Aeromonas Septicemia in Nile Tilapia

“…Which was inoculated by A.hydrophila (3.37×10 9 CFU/ml) reduced the percentage of mortality from 68% to 18% after treatment for 15 days. Also total number of bacteria in polluted aquarium changed from 4.18×10 13 cfu/ml to 7.5×10 7 Cfu/ml after three days of treatments. The efficiency of isolated phages reduction of A.hydrophila in Nile water more than that founded by Donn Cruz-Papa [15].…”

“…Addition of phage to such treatment reduced the mortality to 18% with reduction efficiency reached above 50%. Also phage reduced total count of bacteria from 4.8×10 13 cfu/ml to 7.3×10 7 cfu/ml. on other hand, phages titer in fourth treatments increased above the initial titer of phages it changed from 8.1×10…”

“…A number of phages have been isolated for potential use in phage therapy against important aquatic animal pathogens such as Aeromonas salmonicida in brook trout (Oncorhynchus fontinalis) [12], Vibrio harveyi in shrimp (Penaeus monodon) [13], Pseudomonas plecoglossicida in ayu (Plecoglossus altivelis) [14] and Lactococcus garvieae in yellowtail (Seriolaquin queradiata) [14].…”

Antibiotics in Aquaculture – Use, Abuse and Alternatives

“…Treatment with the bacteriophage in field trials where there was a natural outbreak of V. harveyi improved larval survival and reduced the V. harveyi counts in hatchery tanks (Vinod et al, 2006). Shivu et al (Shivu et al, 2007) also isolated four phages from oyster tissue and a shrimp hatchery that had lytic activity against V. harveyi. These bacteriophages were effective in controlling the population of V. harveyi in hatchery systems and enhanced the survival of shrimp (Penaeus monodon).…”

“…Purified phages of the family Siphoviridae had a clear lytic ability and no apparent transducing properties, indicating they are appropriate for phage therapy (Crothers-Stomps et al, 2010). Although several phages isolated from hatcheries and water from aquaculture systems showed highly lytic activity against V. harveyi (Shivu et al, 2007), some phages that infect V. harveyi occur in a hatchery and co-exist with V. harveyi cells and are unable to control the outbreak of luminescent bacterial disease in a shrimp system Chrisolite et al (2008).…”