an A layer grown in iron depleted and iron supplemented conditions plus cells

An a layer grown in iron depleted and iron

This preview shows page 372 - 376 out of 594 pages.

an A-layer) grown in iron-depleted and iron-supplemented conditions plus cells of Aer. bestiarum in TSB successfully protected goldfish against ulcer disease (RPS > 90%) when administered by immersion (-5 X 10^ cells/ml for 60 sec) fol- lowed by oral boosting over 7 days after 28 days (5 x 10^ cells/g of feed) (Robertson et ai, 2005). Avirulent cells, with altered A-layer, have also been proposed as candidates for live vaccines (Thornton et ai, 1991). However, a compHcation to the various developmental studies comes from the fascinating work of Norqvist et al. (1989), who used live attenuated cells of a different bacterial taxon, namely V. salmonicida, and reported their effectiveness at controlHng infections by Aer. salmonicida. A detailed study revealed that a 28 kDa outer-membrane pore-forming protein (= porin) from Aer. salmonicida led to the development of protective immunity in rainbow trout (Lutwyche et al., 1995). The commercial interest in polyvalent vaccines has resulted in several products, which are regularly used in Europe and elsewhere. The benefit of this approach to controlling furunculosis may be illustrated by the observation that Vibrio antigens, particularly V. salmonicida, appear to enhance the humoral immune response to Aer. salmonicida (Hoel et al, 1997). Moreover, vaccination with V. salmonicida antigens led to protection against Aer. salmonicida following challenge by co-habitation (Hoel et al, 1998a). This approach could well overcome the perceived problem that Aer. salmonicida is a weak antigen (Tatner, 1989). Also, this cross-protection may explain the often superior protection afforded by polyvalent vaccines (Hoel et al., 1998a). Concerning the use of rough and smooth strains for vaccine preparation, dis- crepancies are apparent among results obtained by different groups of investigators. Michel (1979) reported that there was no difference in the effectiveness of vaccines prepared with either rough or smooth cultures, when administered orally or via i.p. injection to rainbow trout. In fact, neither type of vaccine was protective. Yet, circulating antibodies were present in fish which received the vaccines via injection. Cipriano (1982a), examining the effectiveness of vaccines prepared from virulent and avirulent cultures, determined an equal level of protection from passive immunisation of brook trout. Similar agglutinin titres, i.e. 1:512, were found in both groups of vaccinated fish. He concluded, therefore, that protective immunogens were common to both virulent and avirulent cultures. In contrast, McCarthy et al. (1983) reported
Image of page 372
354 Bacterial Fish Pathogens o > o ^ (D ^ > 3 ^ ^ 2 •B -U B B a ^ B U H c^ 'B -B ^ 'B •g x) ^ -S -S :^ Co ^ y ' ^ ^ ^ 8 U W PQ ^ o B ^ ^^ o .^ o .a o .S o ct + o ^ 'S^ ct ^ .a o ct > O PH ^ + ^ r-~- ^ U U H < o U ' T ^ n u o o r- ^ C/5 < n o B I t >< W
Image of page 373
Control 355 N 9^ o^ ' T ^ n ct > o a> O .n PH PH PH o ^ 6 ^ ^ ^ b ^ ::^ b 0 o B It o o U m ^ > ;:3 ^3> 0 O It o o U m ^ > ;:3 ^3> 0 O It o o U > ir^ O O 'ct oi ir^ o O 'ct oi ^ n o 'ct in O n ^ < ^ + w o 'ct in O r^ < ^ w > o ct m < < o O m ^ + o < o O m ^ + o O O O m ;-i + O O O O m ^ + o O O O m n o It in O n ^ < • ^ ;-! a .^ [/5 [/5 'iJ m O m -^ ct ct ^ =^ ^ =^ ^ G G ^ ^ ^ ^ ^ Q-) o o ^ o U o o o U o U c 2 0 o . a ^ i ^ - * ^ ct a O fe < ct o U fe fe ct a O fe ct a O fe ct a O fe fe ct a O fe fe oi ai
Image of page 374
Image of page 375
Image of page 376

You've reached the end of your free preview.

Want to read all 594 pages?

  • Spring '20
  • Bacteria, representative, gram-negative bacteria

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern

Stuck? We have tutors online 24/7 who can help you get unstuck.
A+ icon
Ask Expert Tutors You can ask You can ask You can ask (will expire )
Answers in as fast as 15 minutes
A+ icon
Ask Expert Tutors