EVALUATION OF CROSS-PROTCTION OF AEROMONAS HYDROPHILA AND PSEUDOMONAS FLUORESCENCE DIFFERENT PREPARED VACCINES AGAINST MOTILE AEROMONAS AND PSEUDOMONS SEPTICEMIA IN NILE TILAPIA (OREOCHROMIS NILOTICUS)

EVALUATION OF CROSS-PROTCTION OF AEROMONAS HYDROPHILA AND PSEUDOMONAS FLUORESCENCE DIFFERENT PREPARED VACCINES AGAINST MOTILE AEROMONAS AND PSEUDOMONS SEPTICEMIA IN NILE TILAPIA (OREOCHROMIS NILOTICUS)

Hassanin M. El-Sayed^1* and Mohamed Fathi²

¹Department of Fish Diseases and Management, Faculty of Veterinary Medicine, Zagazig University, Egypt.
²Aquaculture and Genetic improvement, World Fish Center, Abbassa, Sharkia, Egypt

*Corresponding author: Hassanin M. El-Sayed, Phone: +20-1008994986.

E-mail: [email protected]

Abstract

The current work was aimed to evaluate the different prepared Aermonas hydrophilia and Pseudomonas. fluorescence vaccines to develop the best adequate strategy to control such infections in cultured Nile tilapia (Oreochromis niloticus) as well as the cross protection in-between the two pathogens. One thousand three hundred and fifty Nile tilapia were divided to 5 equal groups. Fish in first group was kept as control and injected intra peritoneal with 0.2 mi sterilized saline (0.85%) while groups 2 & 3 were vaccinated intra peritoneal with 0.2 ml (4X10⁸ CFU.ml^-1)
Sonicated cells (SC) suspension and 0.2 ml (4X10⁸ CFU.ml^-1) Extracellular product (ECP) suspension of A. hydrophilia respectively and Fish in groups 4 & 5 were vaccinated with 0.2 ml (4X10⁸ CFU.ml^-1) Sonicated cells (SC) suspension and 0.2 ml (4X10⁸ CFU.ml^-1) Extracellular product (ECP) suspension of Ps. fluorescens respectively.The efficiency of different vaccines was evaluated by nitroblue tetrazoilum (NBT), neutrophil adherence tests, lysozyme activity, the serum bactericidal activity test, antibody titer and challenge test.

The nitroblue tetrazoilum (NBT), neutrophil adherence tests, lysozyme activity showed a significant increase in all vaccinated groups in comparison with control group at 2& 4 week post vaccination. The bactericidal activity and the antibody titer of the serum from fish immunized either by A. hydrophila or Ps. fluorescens vaccines showed higher significant values at 4^th and 8^th weeks post-vaccination in all vaccinated groups in comparison with control. All groups immunized by different vaccines of Ps. fluorescens or A. hydrophila revealed a higher bactericidal activity and antibody titer against Ps. fluorescens than A. hydrophila. Also, all groups immunized by different A. hydrophila vaccines revealed a higher bactericidal activity and antibody titer against A. hydrophila than Ps. fluorescens.

The mortalities percentage of O. niloticus after challenge either by A.
hydrophila or Ps. flourcense showed lower significant decrease in the all immunized groups compared to control group and high relative percent
of survival (RPS).

All prepared Ps. fluorescens or A.
hydrophila vaccines had the potential to induce cross-protection after vaccination against each other in Oreochromis niloticus.

Keywords: Aeromonas hydrophila;
Pseudomonas fluorescens; cross-protection; Oreochromis niloticus.