Characterization and pathological activities of aeromonas bacterial complex isolated from freshwater fish.

by Costa, Andréa Belém

Abstract (Summary)
Bacteria isolated from surubim Pseudoplatystoma corruscans, tilapia Oreochromis niloticus e pacu Piaractus mesopotamicus, were characterized and identified by biochemical, biophysical, serology, and SDS-PAGE, and their virulence observed. The strain isolated from surubim was characterized as Plesiomonas shigelloides. The other strains isolated from tilapia and pacu were Aeromonas hydrophila. The isolated A. hydrophila strains presented virulence and resistance against the follow antibacterial substances: ampicillin, amoxicillin, lincomicin, novobiocin, oxacillin, penicillin, rifampin and trimetoprim+sulfametoxazole. Both strains when cultivated in YEA medium shared with the A. hydrophila type strain a similar protein band of 33,61kDa. In a medium supplemented with glucose, only one protein exhibiting relative molecular mass of 144.28 kDa, was shared by the type strains isolated from fish and the type strain. The serology tests revealed that all isolated strains presented heat-stable O-antigens. The Ouchterlony double-immunodiffusion showed that the antigen prepared from the tilapia strain possessed surface antigens similar to A. hydrophila type strain and the strains isolated from pacu. This suggested the possibility of development and usage of a common or polyvalent vaccine for A. hydrophila among tilapia and pacu or other freshwater fish species.
This document abstract is also available in Portuguese.
Bibliographical Information:

Advisor:Jose Eurico Possebon Cyrino; Debora Machado Fracalossi; Margarida Maria Barros Ferreira Lima; Flavio Ruas de Moraes; Jose Eurico Possebon Cyrino

School:Universidade de São Paulo

School Location:Brazil

Source Type:Master's Thesis

Keywords:animal disease immunology fresh water fish. pathogenicity


Date of Publication:05/29/2003

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