Papel de las actividades superóxido dismutasa y catalasa en la ...

CONCLUSIONS
Studies carried out on the role of superoxide dismutase and catalase activities in
the virulence of Photobacterium damselae subsp. piscicida, and the use of
microorganisms for the control of this pathogen, have yielded the following
conclusions:
1. Photobacterium damselae subsp. piscicida synthetizes only one isoenzyme
with superoxide dismutase activity, characterized by the presence of iron in
its active centre.
2. Photobacterium damselae subsp. piscicida contains only one isoenzyme with
catalase activity, with iron in its active centre.
3. Catalase activity plays an important role in P. damselae subsp. piscicida
resistance against hydrogen peroxide. Thus, bacterial cells with higher
contents of this activity, are able to resist efficiently to hydrogen peroxide.
4. Iron plays a significant role in P. damselae subsp. piscicida survival in the
presence of oxidant radicals, because under iron limiting conditions, lower
levels of superoxide dismutase and catalase activities are detected, and higher
susceptibility to hydrogen peroxide.
5. Photobacterium damselae subsp. piscicida is able to survive as intracellular
pathogen within sole phagocytes, at least for 5 h.
6. Oral administration of red microalga Porphyridium cruentum, in combination
with intraperitoneal inoculation of a bacterin containing P. damselae subsp.
piscicida cells, increases respiratory burst activity.
7. Oral administration of Shewanella strains Pdp11 and Pdp13, proposed as
probiotics, increases respiratory burst activity and confers protection against
experimental infection with P. damselae subsp. piscicida, respectively.
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