Bacterial clearance in the sea urchin, Strongylocentrotus purpuratus Public Deposited

http://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/4x51hn625

Descriptions

Attribute NameValues
Creator
Abstract or Summary
  • Characteristics of bacterial clearance were investigated in the purple sea urchin, Strongylocentrotus purpuratus (Echinodermata: Echinoidea). Primary clearance kinetics were determined for three bacteria, a marine Gram negative motile rod, a marine Gram positive non-motile rod, and a fresh water fish pathogen, Aeromonas salmonicida. Various doses of live bacteria were injected into the perivisceral coelom of urchins, and coelomic fluid samples were removed for viable counts. Clearance of the two marine bacteria occurred in two stages. Reduction in viable counts was rapid and exponential during the first 90 min, followed by a period of slower clearance. The two bacteria exhibited similar clearance rates during the first 90 min, however the Gram positive bacteria were subsequently cleared more slowly than the Gram negative. Clearance of A. salmonicida was linear and not in two stages, although the initial rate of clearance was much lower than that of the marine bacteria. Attempts were made to determine whether a memory or inducible component exists in S. purpuratus' response to bacteria. After the kinetics of clearance of primary injections had been determined, the same urchins were challenged with a second injection of bacteria (9, 14, and 21 days after primary injections for the two marine bacteria, 19 days for A. salmonicida). The secondary clearance rates were not significantly different from the primary clearance rates for any of the three test bacteria. The cell-free coeloraic fluid of S. purpuratus was tested in vitro for bacterial agglutination and bactericidal activity against the two marine bacteria. Declines in viable counts of bacteria were observed with both bacteria in coelomic fluid, while viable counts in sea water controls did not change. Neither previous injection of urchins with bacteria nor prior heating of coelomic fluids (100°C, 10 min) significantly altered the viable counts. It is not clear from these experiments whether the declines in viable counts were due to bacteria killing or agglutination. However, when the coelomic fluid was tested, agglutination was not observed with either of the bacteria. The cellular responses of the urchins were also investigated. After injection of Gram negative bacteria, total numbers of circulating coelomocytes declined by 93% by 90 min after injection, and decreased slowly thereafter. By 24 hr, cell counts had risen, but not to preinjection values. All four coelomocyte cell types contributed to the overall decline. The proportions of coelomocyte types also changed during the 6 hr after injection. A fluorochrome dye, acridine orange, was used to observe phagocytosis and killing of bacteria. Clotting phagocytes trapped and engulfed bacteria. Within 2 hr after mixing bacteria and coelomocytes in vitro, dead bacteria were seen in some of the phagocytes.
Resource Type
Date Available
Date Copyright
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome, 8-bit Grayscale) using ScandAll PRO 1.8.1 on a Fi-6670 in PDF format. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR.
Replaces
Additional Information
  • description.provenance : Submitted by Katy Davis (kdscannerosu@gmail.com) on 2013-08-15T17:48:38Z No. of bitstreams: 1 YuiMaryA1982.pdf: 718880 bytes, checksum: d077ee8ae38e7c452b29d60c8cb7c6f1 (MD5)
  • description.provenance : Made available in DSpace on 2013-08-27T14:57:01Z (GMT). No. of bitstreams: 1 YuiMaryA1982.pdf: 718880 bytes, checksum: d077ee8ae38e7c452b29d60c8cb7c6f1 (MD5) Previous issue date: 1981-12-14
  • description.provenance : Approved for entry into archive by Patricia Black(patricia.black@oregonstate.edu) on 2013-08-15T17:53:27Z (GMT) No. of bitstreams: 1 YuiMaryA1982.pdf: 718880 bytes, checksum: d077ee8ae38e7c452b29d60c8cb7c6f1 (MD5)
  • description.provenance : Approved for entry into archive by Patricia Black(patricia.black@oregonstate.edu) on 2013-08-27T14:57:01Z (GMT) No. of bitstreams: 1 YuiMaryA1982.pdf: 718880 bytes, checksum: d077ee8ae38e7c452b29d60c8cb7c6f1 (MD5)

Relationships

In Administrative Set:
Last modified: 08/23/2017

Downloadable Content

Download PDF
Citations:

EndNote | Zotero | Mendeley

Items