Papel de las actividades superóxido dismutasa y catalasa en la ...
Papel de las actividades superóxido dismutasa y catalasa en la ...
Papel de las actividades superóxido dismutasa y catalasa en la ...
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INTRODUCTION<br />
pathog<strong>en</strong>s, study of these activities in P. damse<strong>la</strong>e subsp. piscicida could contribute to<br />
the un<strong>de</strong>rstanding of the interactions betwe<strong>en</strong> this bacterium and its host.<br />
Barnes et al. (1999a) <strong>de</strong>termined the exist<strong>en</strong>ce of a perip<strong><strong>la</strong>s</strong>mic FeSOD and a<br />
citop<strong><strong>la</strong>s</strong>mic cata<strong><strong>la</strong>s</strong>e, not characterized. The SOD activity is repressed un<strong>de</strong>r iron<br />
restricted or low oxyg<strong>en</strong> conditions. Cata<strong><strong>la</strong>s</strong>e activity is constituvely expressed,<br />
although there are differ<strong>en</strong>ces in int<strong>en</strong>sity gel bands <strong>de</strong>p<strong>en</strong>ding on strains. In this PhD.<br />
Thesis we have tried to <strong>de</strong>ep more in the study of the role of superoxi<strong>de</strong> dismutase and<br />
cata<strong><strong>la</strong>s</strong>e activities in P. damseale subsp. piscicida virul<strong>en</strong>ce.<br />
4. STIMULATION OF RESPIRATORY BURST ACTIVITY BY<br />
DIFFERENT MICROORGANISMS AFTER Photobacterium<br />
damse<strong>la</strong>e subsp. piscicida INFECTION<br />
4.1. PREVENTION AND TREATMENT OF PSEUDOTUBERCULOSIS<br />
Over the <strong><strong>la</strong>s</strong>t <strong>de</strong>ca<strong>de</strong>, inci<strong>de</strong>nce of drug-resistant strains, carrying a transferable R-<br />
p<strong><strong>la</strong>s</strong>mid have increased, making treatm<strong>en</strong>t with antimicrobial chemotherapeutics less<br />
successful. Moreover, a period of intracellu<strong>la</strong>r parasitism within macrophages has be<strong>en</strong><br />
<strong>de</strong>scribed for P. damse<strong>la</strong>e subsp. piscicida (Kusuda and Sa<strong>la</strong>ti, 1993); this finding can<br />
exp<strong>la</strong>in the ineffectiv<strong>en</strong>ess of chemotherapy in the treatm<strong>en</strong>t of some disease outbreaks.<br />
Therefore, immunoprophy<strong>la</strong>xis has become the best way to prev<strong>en</strong>t pseudotuberculosis.<br />
Throughout the <strong><strong>la</strong>s</strong>t 20 years, there have be<strong>en</strong> a variety of studies analyzing the<br />
effectiv<strong>en</strong>ess of immunization in prev<strong>en</strong>ting pseudotuberculosis (Romal<strong>de</strong> and<br />
Magariños, 1997). Most vaccine formu<strong>la</strong>tions tested consisted of heat- or formalin-killed<br />
cells (Fukuda and Kusuda, 1981; Kusuda and Hamaguchi, 1987; Kusuda and Hamaguchi,<br />
1988; Hamaguchi and Kusuda, 1989). Best results were obtained using formu<strong>la</strong>tions<br />
based on lipopolysacchari<strong>de</strong>s (LPS) and ribosomal fractions of the bacteria (Fukuda and<br />
Sukuda, 1985; Kusuda et al., 1988; Kawakami et al., 1997). However, these formu<strong>la</strong>tions<br />
pres<strong>en</strong>ted not only problems of reproducibility, but also difficulties on <strong>la</strong>rge scale<br />
production. Passive immunization has also be<strong>en</strong> evaluated (Fukuda and Kusuda, 1981),<br />
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