Antibacterial activity of silver nanoparticles (AgNps) synthesized by tea leaf extracts against pathogenic Vibrio harveyi and its protective efficacy on juvenile Feneropenaeus indicus.

To determine the antibacterial potential of silver nanoparticles (AgNps) synthesized by tea leaf extract against Vibrio harveyi and its protective effect on juvenile Feneropenaeus indicus. AgNps were synthesized by a simple procedure using tea leaf extract as the reducing agent. Bacteriological tests were performed in Luria-Bertani medium on solid agar plates and in liquid systems supplemented with V. harveyi against different concentrations of AgNps. AgNps synthesized in the present study were shown to be effective against V. harveyi isolated from F. indicus. The combined results of long- and short-term treatment of AgNps synthesized by tea leaf extract showed a 71% reduction in accumulated mortality. The long-term administration of AgNps synthesized by tea leaf extracts at the concentration of 10 microg significantly reduced the mortalities in F. indicus from V. harveyi infections. The AgNps synthesized by tea leaf extract may be an alternative to antibiotics in controlling V. harveyi infections.