Electrostatic mechanism of survival of virulent Aeromonas salmonicida strains in river water.
AUTOR(ES)
Sakai, D K
RESUMO
The ecological mechanism of survival of Aeromonas salmonicida, the bacterial pathogen of fish furunculosis, in river water was investigated by laboratory-based experiments with two virulent strains (which were autoagglutinating) and two virulent strains (which were nonagglutinating). A difference in net electrical charge of A. salmonicida cells was detected by electrophoresis; cells of the virulent strains were negative, whereas cells of the avirulent strains were positive. Despite the loss of viable cells within a week in distilled water and physiological saline (0.85% sodium chloride), the cells of the virulent strains survived for more than 15 weeks in the presence of diluted humic acid (10 micrograms/ml), tryptone (10 micrograms/ml), and cleaned river sand (100 g/100 ml of medium), but loss of viable cells occurred within 5 weeks in the absence of sand. The cells of the avirulent strains lost viability within 2 weeks with no relation to the presence of sand. Using ion-exchange columns, humic acid and the amino acids of tryptone were found to be anionic and cationic in water (pH 7.0), respectively. Sand particles had a high capacity to adsorb humic acid alone and amino acid-humic acid complexes. Thirty to fifty times the environmental concentration of amino acids (10 micrograms/ml) were accumulated on the surface of sand particles, thereby permitting only bacterial cells carrying net negative electrical charges (virulent cells) to survive for a long period on the surface of the sand particles. These electrostatic interrelationships among river sand, humic acid, and bacterial cells are closely implicated in the mechanism of long-term survival of virulent A. salmonicida in river sediments.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=239068Documentos Relacionados
- Electrostatic Mechanism of Survival of Virulent Aeromonas salmonicida Strains in River Water
- Survival of Aeromonas salmonicida in lake water.
- Survival of nonculturable Aeromonas salmonicida in lake water.
- Molecular Characterization and Quantitative Analysis of Superoxide Dismutases in Virulent and Avirulent Strains of Aeromonas salmonicida subsp. salmonicida
- Adhesion of Aeromonas salmonicida strains associated with net electrostatic charges of host tissue cells.